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Gear Ratio Chart

The below table can be used to get a rough idea on gear ratios. The colors represent ideal RPM's at highway speeds (65). For highway cruising and best fuel economy stay towards the yellow (2600 rpm), around town daily driving is color coded green (2800 rpm), and for better towing power or just more 4-low power use the ratios near the red (3100 rpm). These calculations are assuming a manual transmission with a 1:1 ratio. If you drive an automatic your RPMs will be slightly higher, and the opposite is true if you have overdrive (your RPMs will be slightly lower).

  Better Gas Mileage 

 Near Factory Ratio  More Power 

 

Gear Ratio
T
i
r
e


D
i
a
m
e
t
e
r
3.313.423.553.733.914.114.274.564.885.135.295.385.716.177.17
27"267727662872301731633325345436893947415042794352461949915800
28"258226682769290930503206333135573806400141264196445448135593
29"249325762674280929453095321634343675386339844052430046475400
30"241024902584271528462992310933203553373538513917415744925220
31"233224092501262827552896300832133838361437273790402343475051
32"225923342423254626962805291431123331350136103672389742114894
33"219122632349246925882720282630183230339535013561377940934745
34"212621972280239625122640274329293135329533983456366839634606
35"206521342215232824402565266428453045320133013357356338504474
36"200820752154226323722493259027662961311232093264346437434350
37"195420192095220323082426252026922881302831233176337036424243
38"190219662040214422472362245426212805294830403092328235464121
39"185419151988208921902302239125542733287329623013319834554015
40"180718671938203721352244233124902664280128882937311833693915
41"176318221891198720832189227524292599273328182866304232873819
42"172117781846194020332137222023712538266827512798296932083728
43"168117371803189419862087216923162479260626872733290031343642
44"164316981762185119412040211922632422254626262670283430633559

Exactly how do you flush your radiator?

  1. Begin with the engine cold and ignition off. Remove the radiator cap. MAKE SURE THE ENGINE IS COOL. If the radiator cap is too hot to touch, your engine is not cool enough.
  2. Open the drain-plug at the bottom of the radiator and drain the coolant into a bucket. You will want to dispose of the cooling fluid as environmentally conscious as possible. So, if there are any shops or recycling places in your area that take old coolant give it to them. Make sure you keep the fluid away from animals. Don't just pour it on the ground. Animals tend to want to drink it, but it will kill them. My ex-girlfriend's dog died of this once.
  3. Close the drain-plug and fill the radiator with water.
  4. Start the engine and turn the heater control to hot (this will open the heater control valve). Add cooling system cleaner and idle the engine for 30 minutes (or as per the instructions on container).
  5. Stop the engine and allow it to cool for five minutes. Drain the system.
  6. Close the drain-plug, fill the radiator with water and let the engine idle for five minutes.
  7. Repeat step No. 5. Close the drain-plug.
  8. Install new 50/50 mixture of water and ethylene glycol antifreeze/coolant. Be sure you use the same coolant as was in your vehicle. Many of the coolants that are designed to last 150,000 miles will react with cheaper coolants and cause corrosion of the radiator. The best way to do this is match color. If it says "Dex-Cool" or something of that nature, definitely use a Dex-Cool variant.

It's that simple! Good luck.

AXLE TERMINOLOGY

AXLE SHAFT SEMI-FLOATING - Shaft that carries vehicle load and transmits torque.
BACKLASH - The amount of clearance or play between two meshed gears.
BANJO-AXLE DESIGN - An axle assembly with a final drive assembly that assembles into the housing and is bolted into place.
BEARING CAP - The portion of the axle housing that is bolted in place to secure the differential bearings and differential assembly.
BEARING CONE - The inner race of a tapered roller bearing.
BEARING CUP - The outer race of a bearing assembly.
CARRIER - The casting center section of a drive axle that contains the differential assembly, ring gear, pinion gear and support bearings.
CENTER SECTION - The carrier portion of a drive axle.
COAST - A load condition in which the vehicle is driving the engine, as during deceleration.
DECELERATE - To reduce speed.
DIFFERENTIAL - A gear arrangement that allows the drive wheels to be driven at different speeds and divides the input torque of one shaft between two output shafts.
DRIVE - A load condition in which the engine is applying power to the wheels.
DRIVE GEARS - A large gear that meshes with a smaller gear. Also known as a Crown Gear.
END YOKE - Yoke-shaped forging that forms part of the universal joint connection the drive shaft to the transmission or axle.
EXTREME PRESSURE (EP) LUBRICANT - A lubricant designed to stay in place and keep the gears from touching when under extremely high pressure (e.g., heavy torque loads).
SALISBURY AXLE DESIGN - Axle assembly with final drive components assembled into one piece housing.
SHIM - A thin spacer used to adjust preloads and ring gear to pinion gear backlash may also be used for controlling pinion gear positions.
FLOAT - A load condition where two parts are turning at the same speed with no driving force between them.
FLANGE YOKE - Same as an end yoke except circular in design.
FULL-FLOATING AXLE - Axle shaft which transmits torque only and carries no vehicle load.
GEAR - A wheel with teeth that transmits power or motion to another gear.
GEAR RATIO - The ratio in the number of teeth on the driving and driven gears; it is calculated by dividing the number of teeth on the driven gear by the number of teeth on the driving gear.
HEEL - The outer end of a bevel or hypoid ring gear tooth.
HOUSING - Portion of the axle assembly that consists of the carrier and axle tubes.
HYPOID GEAR - A special form of bevel gear that positions the gear axis on non-intersecting planes and is commonly used in drive axles.
LIMITED SLIP DIFFERENTIAL - Differential in which the difference in rotational speed or torque between two output shafts is mechanically limited to prevent wheel spin on difficult terrain.
NEWTON METER (N.M.) - The metric measurement of torque.
PINION GEAR - A small gear that meshes with a larger gear.
PITCH LINE - The effective diameter of a gear; midpoint of the gear tooth.
PRELOAD - A load placed on parts during assembly to maintain critical clearances and adjustments when operating loads are applied.
R.T.V. - A formed-in-place gasket material; a rubber like compound that vulcanizes at room temperature.
TOE - The inner end of a bevel or hypoid ring gear tooth.
TORQUE - A turning or twisting force that is normally measured in pound-feet or Newton meters.
VISCOSITY - The resistance to flow of a fluid.

AXLE TROUBLESHOOTING

ISSUEPOSSIBLE CAUSES
Noise in all driving modesRoad and tires, wheel bearings
Noise changes with type of road surfaceRoad and tires
Noise tone lowers with vehicle speedTires
Noise louder on turnsDifferential pinion and side gears, axle wheel bearings
Noise in one or more driving modesRing and pinion gears
Clunk on change of speed or direction of power flowWorn differential shaft or thrust washers; worn U-joints
Wheel noiseWheel loose, faulty or bad wheel bearing
VibrationDamaged drive shaft, missing drive shaft balance weight, worn or out-of-balance tires, loose wheel lug nuts, worn U-joints, loose spring U-bolts, loose/broken spring, damaged axle shaft bearings, loose pinion gear nut, excessive pinion yoke run-out, bent axle shaft
Differential gears scoredInsufficient lubrication, improper grade of lubricant, lubricant contamination, excessive spinning of tires
Loss of lubricantLubricant level too high, worn axle shaft seals, cracked differential housing, worn drive pinion gear shaft seal, scored and worn yoke, axle cover not properly sealed, plugged vent or vent tube
Axle overheatingLubricant level too low, incorrect grade of lubricant, contaminated lubricant, bearing preload too high, excessive gear wear, insufficient ring gear backlash
Gear teeth brokenOverloading, erratic clutch operation, wheel spinning, improper adjustment
Axle gear noiseInsufficient lubricant, incorrect backlash, improper tooth contact, worn/damaged gears
Axle noiseInsufficient lubricant, improper ring gear and drive pinion gear adjustment, unmatched ring gear and drive pinion gear, worn teeth on ring gear or drive pinion gear, loose drive pinion gear shaft bearings, loose differential bearings, misaligned ring and pinion gear, loose differential bearing cap screws, worn bearings
Limited slip differentialThe most common problem is a "chatter" noise when turning corners. The probable cause is incorrect or contaminated lubricant or lack of friction modifier additive in the lubricant, worn or damaged plates and discs, plates and discs improperly assembled

52" Front Spring Swap

Introduction:

As CK5'ers, many of us are looking for mods that not only increase our rigs off-road capability, but can also be done in an inexpensive way that we can install ourselves, "built not bought" and all of that good stuff.

Suspension upgrades for full-size Chevys have traditionally tended to focus on the rear suspension. Upgrades like Teraflex's Revolver shackles, the Marv Springer-designed AK57 kit and Off Road Design's shackle flip kit are examples of common suspension upgrades. The average K5 owner has traditionally matched these with aftermarket lift springs up front to level things out. This is an acceptable way to raise a full-size, but what if there was a cheaper alternative that added lift (4-5"), increased front-end flex and could be installed at home by the average Joe with nothing more exotic than the standard selection of tools?

Enter the 52" spring swap! 52s are stock K5 rear springs and are commonly found in parts yards, on 4x4 web sites or, if you plan on running other-than-stock springs in the rear suspension, the back of your very own K5! That is the main draw of this swap, the springs can be had dirt cheap-to-free almost anywhere. Aftermarket pieces like Tuff Country, BDS, Deaver or Alcan springs are certainly high quality and flex well for stock-length springs, but they are also a lot more expensive, and probably won't provide better flex than the longer 52" springs would. I had been running Rancho HD 4" lift springs in my rig and they would hardly flex at all. When my rig got twisted up, it was clear that almost all the suspension action was happening in the rear with very little movement up front. If you're like me, you're looking for a better solution, so grab a set of 52s and let's get started! 

Part I: Spring Preparation:

Ok, so you've got an old pair of stock 52" springs, now what? Before diving in to the spring swap itself, you might consider spending some time rebuilding your stockers. I don't know about your leaf springs, but the ones I had were crusty with dirt, road grime and some surface rust. The whole point of doing this upgrade is to increase flex and with gunked up springs you're just not going to get the maximum benefit of the swap.

The first step is to get your spring packs taken apart. The center pin uses a 9/16" nut. The other end is round, which can make it pretty hard to get a hold of it well enough that it doesn't spin while you try to wrench the nut off. I usually start by putting a pair of vice grips on the round end and see if that will work. If not, one trick is to use a grinder to carefully grind the pin down so it has two opposing flat sides on it that are easier for pliers or a vice to hold onto without spinning. If the pack is so crusty that even that won't work, I just grind the head down until it's flush with the spring and use a center punch to push it out the other side of the pack. A torch would work too, but I don't own one and I'd rather avoid the risk of damaging the leaves.

Crusty Springs

Once the center pin is out, its time to inspect the leaves. You'll want to make sure that there are no cracks, excessive pitting or other physical damage. Inspection of the main leaf should be especially thorough. If one of the other leaves cracks or breaks on the trail, it's not the end of the world. If the main leaf breaks, it could be a major PITA, so give it a good look. If the leafs appear serviceable, its time to clean them up.

The easiest way would be to sandblast them, but since most of us don't have a media blasting rig in our garage, I had to use a ton of elbow grease instead. I started off by using soapy water and an old nasty scrub brush to get the big chunks. Honestly, this got some dirt off but didn't even put a dent in the grime. The next thing I tried was drill-mounted wire brush. This method takes awhile, but did a very good job of getting most of the crap off my leaves. I tried not to use any kind of device that would remove material from t he leaf itself. I'm sure a flapper wheel on a grinder would have worked great and been a lot faster than the drill-mounted wire wheel, but I just didn't want to risk damaging the base metal just to save a little sweat. A good wipe down with mineral spirits afterwards and the springs were clean enough for me. Once my leaves were clean, I noticed that the ends of some of them had some sharp 90 degree edges on them which wore on the leaf above during compression. I used a few swipes with the grinder to smooth these edges out a bit. You can take this a step further by using a grinder to round the ends of your springs, but I decided simply removing the sharp edge was good enough for the time being and the extra effort not worth it. 

At this point, I busted out some rattle-can primer and added a thin coat to each leaf to protect it from rusting during the rebuild. Setting the rest of the leaves aside, I put the main leaves on the work bench. The 20 year old factory rubber bushings were completely shot, of course, so I had to remove them. This is a process that is ten times easier with a better equipped shop. With a press or torch this is a 5 minute job. For the rest of us, it can be a pain. The easiest way for us tool-deprived souls is to drill a bunch of holes in the rubber around its perimeter so that the whole thing can be hammered out. Problem is, the bushings are rounded on the ends so it's hard to get a drill to go straight in without walking all over the place or going in at an odd angle and potentially breaking the bit.

To solve this, I cut off that rounded part of each bushing with a cut off wheel (a sawzall would work too) so it's flush with the sides of the spring eye. This gives me a flat surface to work with that is much easier to drill into. From here, I use what I call the "drill and chunk" method. Basically, you drill 8-10 holes around the bushing. Then flip the spring over and do the same thing to the other side. This process takes some time because the rubber creates a lot of friction on the drill bit and it tends to get hot very quickly. In the past I've found it handy to use two drills and alternate them with each hole. This definitely helps, the last thing you want to do is toast a bit and break it off inside the bushing, they are enough of a PITA already. Anyway, once you have a good selection of holes drilled you take some needle nose pliers, some flathead screwdrivers and any other tool you have laying around that will fit and pry/pull/tear chunks of the rubber out.

This is a tedious process and it's amazing how strong the bushing can hold on even after you have removed half of its volume. Pretty annoying. At some point you won't be able to get any more chunks of rubber out and its time to repeat the process and drill some more. Eventually the bolt sleeve will start to get loose enough that you can use a hammer and pound it and the rest of the bushing the rest of the way out. Now all you have to do is do that same thing three more times. fun!

Primered SpringsToast Bushings

New bushings are available from many places, the bushings I used are poly and are much more durable than the stockers. They also have a shoulder that is 1/4" wider than the stock 52" springs bushings. This is a good thing because that extra width matches them up perfectly with your stock front hangers and shackles. Keep in mind that if you just go to a 4x4 parts supplier and order new bushings for rear K5 springs, they won't be the right size and you'll have to use some sort of spacers or thick washers to make up the difference. I don't know what the application is for the wider bushings that I bought, but any vendor with a catalog can look them up by their dimensions. The ones I have are 1.5" in diameter inside the spring eye, 3.5" wide overall with a 1/2" shoulder on each side and a ¾" hole in the middle which has a steel sleeve that allows a 9/16 bolt). As you may have noticed, these bushings are larger in diameter than the stockers. This is because they are designed to be used in a factory leaf but without the factory steel sleeve in the eye.

Removing these spring eye sleeves is a job that, again, would be easier with better tools. My tool selection kinda sucks, but I can make do with a sawzall, center punch and a flathead screw driver. These sleeves are held in by friction so a good soaking with WD40 or liquid wrench the night before you do this might help. Leaf springs tend to be awkward to work on, so I used a C clamp to hold them securely to my work bench. Then I use a sawzall to cut the sleeve. It's important to take this step slowly, because you don't want to cut all the way through the thin sleeve and damage the eye of the spring. The best approach is to cut as much as you think you can without actually going all the way through, stopping frequently to make sure that you haven't. Once there is a good notch in the sleeve, I lay the spring on its side and use a flat screwdriver and hammer to bend the lip of the sleeve up right next to the notch I just cut with the sawzall.

Best not to use your favorite screwdriver for this, as it is possible that you'll break it. Pound the screwdriver straight into the gap, don't try to twist it or pry with it or anything. Doing so probably will break your screwdriver and it really isn't necessary because as the part of the screwdriver pushing in between the spring eye and sleeve gets thicker, it will separate the two by itself anyway. You just need to get enough of a gap in there that it allows the end of a center punch to fit in between the sleeve and eye. Once you have the edge of the sleeve peeled back a bit, grab your center punch. The idea here is to pound in the punch with a hammer, which will fold the sleeve inward along the notch you just made with the sawzall, cutting the sleeve in half in the process and allowing its removal. What's left of the sleeve at the bottom of the sawzall notch is very thin, and the force of the punch should have no problems rupturing it and pushing the ends inward. Several good whacks and the punch will go all the way in and the sleeve should look something like the picture. At this point it's just a matter of using a hammer, pliers etc. to remove the punch, and pounding the mangled sleeve the rest of the way out. I use a spare bolt for this, and it works pretty well. There isn't much left holding the sleeve in at this point, so a few whacks and it should come right out.

Sawzalled SleeveScrewing Sleeve

Punchin the SleevePunched through SleevePushing out Sleeve

I found the insides of the eyes in my springs to be a bit rusty. A quick scouring job with an SOS pad and they were good to go. A little more primer and the bushings are ready to go in. I slather grease all over my bushings when I install them. I think it helps with long term durability, not to mention ease of installation/removal.

The final issue with the stockers is that the factory Teflon pads put between leaves aren't especially durable (some 52" packs don't have these pads from the factory, others do). One of the sets of 52s I had showed considerable wear on each leaf from the leaf below it rubbing against it during compression. This friction not only reduces suspension movement but, over time, grinds material off the spring, weakening it. To combat this I use UHMW-PE or Ultra High Molecular Weight Poly Ethylene. UHMW-PE is a linear polymer with a molecular weight between 3,100,000 and 6,000,000. This high molecular weight gives the material outstanding abrasion resistance (30 times more than Teflon) and a high impact strength too. It has a low coefficient of friction and is self lubricating. It will not cold flow as readily as Teflon and won't absorb moisture either. It can operate at a continuous temperature of 180 degrees F, and withstand temporary temperatures over 220.

If you live in Canada or some other super chilly environment, fear not... UHMW-PE can withstand cryogenic freezing temperatures without a problem. In its most common form, UHMW-PE is not UV stable, but manufacturers can use additives to make it so. I doubt this is a concern in our case, since it will spend its life sandwiched between leaf springs underneath a truck. UHMW-PE is a cool material with lots of potential uses in your 4x4. It's also easy to use and can be cut with good set of scissors. It comes in many thicknesses, but I've found either 0.030" or 0.060" to work the best with leaf springs. In its natural form its white in color, but some manufactures produce the same material in different colors as well. I got mine in black at no extra cost from my local plastics supplier (http://www.multicraftplastics.com).

The vast majority of spring bind occurs at the ends of the leaves, but I didn't have a simple way to cover just the ends so I cut the UHMW-PE to lengths about 3/4" longer than each leaf, drilled a hole in the center for the spring pack's center pin to go through and mounted it that way. The center pin and spring clamp(s) keep it from going anywhere and with the material running from end to end you won't have to worry about the springs binding and wearing against each other ever again. I first read about using this material in leaf springs in one of the 4x4 mags a few years ago so it's not some wacky experimental stuff I came up with on my own one day. It's tested and it works. 

Part way through this process I saw several posts on CK5 talking about the use of the overload leaf. Some people used it... some people used it but cut it shorter... still other people removed it from the pack entirely. I decided that I didn't want to run the overload. This was based on two factors. First, it hangs down below the rest of the spring pack a good amount and could easily get caught on terrain before the tires can get me up and over. Second, I am going to relocate my tie rod behind my axle with WFO Concepts trick steering arms (http://www.wfoconcepts.com) so I want my spring pack to be as thin as possible for maximum tie rod clearance while at the same time still providing a good amount of lift. Because of this, I decided to take one leaf from another set of 52s and add it to the new packs.

This leaf is half as tall as an overload, so the clearance for the tie rod in increased, but it's arched, so I shouldn't lose much in the way of lift. This is a good thing, because the eventual goal is to replace my 39.5x15x15 TSLs with 42" Iroks. Whether you keep the overload or not is a matter of personal preference, the springs would work either way. Some people have suggested using the overload because it works like a bump stop to help limit a flexy suspension, I plan on using real bump stops so I wasn't especially concerned about running a pack without them. If you're not, you might consider running the overloads in your packs.

Last thing to do before assembly is to paint the springs. Some people use graphite impregnated spray paint on leafs to help reduce bind. That's not a bad idea, but I have heard that this paint isn't especially durable in this application and with the UHMW-PE between each leaf, it would probably be redundant, so I just used some common rattle can gloss black on mine to help keep rust at bay. Once they are nice and dry, its time to put the packs together.

To hold the packs together, you'll need new center pins. Some people use grade 8 bolts with the heads ground round. That would work fine. Personally, I have a good local spring shop and get them there. If I am buying anything else there, like u-bolts, they will usually toss in some center pins for free. Score. I have found it to be worthwhile to have a good relationship with the local spring shop, they can make custom u-bolts in minutes and they are always cheaper than those available from the lift manufacturers and retail 4x4 shops. If you haven't done so already, you might consider this a good excuse to pick up the phonebook and find a good spring shop in your area. Anyway, I use a deep 9/16" socket to spin the nut on while holding the other end of the pin with a pair of pliers. It doesn't take much pressure to stop it from spinning. This is good because you don't want to damage the center pin which could make it hard to slide into the spring perch later on. Once the nut is good and tight I used a cutoff wheel on my grinder to chop the pin off about 2-3 threads above the nut so they will fit under the spring plates. 

Shazam! 1 set of rebuilt 52" springs!

Part II: The Swap

Your springs are now ready to go so its time to actually swap them in. Before you start, it's a good time to measure the frame-to-axle distance for a reference point so you'll know how much lift the swap provides. The first step is to put the rigs frame up on stands, getting the weight off the front suspension. Since you'll be under the rig at times during this upgrade, it's a smart idea to make sure the frame is well supported. I have a set of four cinder blocks that I use which I have attached a piece of 3/4" plywood to one side with liquid nails and then filled in the holes in the blocks with concrete. People 'in the know' say you should never use cinder blocks to support of vehicle, but these have works flawlessly for me for years. The plywood helps distribute the pressure from the jack stands footing, and the filled-in block has significant strength in compression.

They are heavy as hell and awkward to move around, but they work. Anyway, I don't recommend cinder blocks to others, especially an unmodified one, but whatever you use, be safe. We want a trick new suspension, not a poor guy crushed under his rig because he didn't support it properly while working on it. Anyway, once it's up on stands, remove the front tires/wheels and shocks to get them out of the way. Set up some jack stands under your axle, double check that the springs are not under compression, and remove the u-bolts. Once the axle is safely supported by the stands, unbolt/remove the leaf springs and shackles from their mounts on the frame so you have a clean slate to work with. Since this spring swap requires axle relocation, you might as well disconnect the drag link from the steering arm too. It will probably have to be adjusted for length anyway. There should only be two things connecting the axle to the rest of the rig at this point brake lines and the driveshaft. I like to keep the driveshaft connected; it stops the axle from rotating on the jack stands due to the weight of the pumpkin.

Up on StandsRemoving old SpringsOld Springs/shackles Removed

These new springs are longer than your stock ones, so you're going to need to rearrange your spring hangers in order to use them. There are several ways to do this, but the most common is to relocate this L-bracket from behind the body mount to in front of it. This is a good method mainly because it requires no fabrication whatsoever (read: cheaper/faster). The stock bracket is plenty strong, I've never heard of a factory one failing. My factory L-brackets have held up fine for years so there really isn't any need to fabricate a new bracket if you don't want too. You will, however, have to remove the factory rivets.

There are six rivets securing each spring hanger, and two other rivets holding each L-bracket to the frame for a total of 16 rivets. This can be a real pain without the right tools, but it is possible with just a drill, bit and patients. I have a 4.5" angle grinder, so I've found the easiest thing for me to do is to just grind one side of the rivet down flush with the frame, then use a bit of drilling to weaken its grip on the frame and finally a punch and hammer to pound it out. Anyone who has installed an ORD (http://www.offroaddesign.com) shackle flip bracket knows what the rivet removal process is like, the only difference here being that some of the rivets are a bit harder to get at. Sometimes these suckers are resilient so this process can definitely take some time. You guys with air chisels, torches and the like will be done in 10 minutes, the rest of us have to suck it up and use our caveman-like tools to will them out. About the time I finished getting all my rivets out the hard way, I read a forum post about removing them with nothing but a chisel, punch and a BFH. That definitely would have been the faster way to go if you don't have air tools and can get the technique down.

L Bracket MoveRivets to Remove 1
Rivets to Remove 2Front Hangers Removed

Once the rivets are gone, the L-bracket and spring hanger can be moved in front of the body mount as shown. The factory rivets have a 3/8" shank. Since I had everything apart anyway, I decided to drill the holes out to a slightly larger 7/16". I did this for several reasons. First, I could tell that some of the holes edges/sides were slightly deformed after years of abuse and/or the removal process and hogging them out to a larger size would get me "new" steel to work with. Second, the minor diameter of a 3/8" bolt is significantly smaller than 3/8 of an inch because of the threads. If the materials were the same, the rivet would be stronger than the bolt and the results of my mods would be a weaker connection between the frame and hangers. Of course, SAE grade 8 hardware is tougher than the material used in factory rivets, but still, I wanted the mods I was doing to be an upgrade in every way. Therefore, the larger 7/ 16" bolts seemed like the way to go. They are spec'ed for a higher preload and have a 25%+ greater clamping force and shear strength than the smaller 3/8" bolts would have had. 

Once I had all the factory rivet holes drilled out to 7/16", I found that I'd need to drill 4 more holes into the frame (on each side) so the spring hanger and L-bracket could be bolted on in their new location. Before I did that though, I went over the frame and the brackets with a wire wheel and flapper disc, which cleaned them up nicely. They were practically bling afterward so I gave them a good coat of rattle can primer and paint. With that done, I used 1" x 7/16" grade 8 bolts, hardened washers and all metal locking nuts to bolt everything on.

The weight of your rig is going to rest on these few bolts, so don't mess around with lower grade bolts just because they are cheap. I like to pinch pennies more than most people, but even I'm not going to risk my rig (and possibly my life) just to save a few dollars on nuts and bolts. Since I was going to need so many of these bolts/nuts, I decided to drive the extra distance to my local bolt/nut distributor , Vancouver Bolt and Supply (http://www.vancouverbolt.com), rather than the closer hardware store. The former almost always has what I need in stock and is cheaper as well. Like the spring shop, a local, high quality hardware distributor is a good place for a gear-head to be on good terms with. With the front hanger relocated and ready to go, its time to look at the rear spring mounting situation.

L Bracket after move

With the rear shackle hanger in the stock location, shackle angle is not going to be ideal. The point of doing this spring swap is to greatly increase suspension flex. Shackles mounted in the stock position are going to give you a terrible shackle angle and therefore limit the suspension travel we seek. The easiest way to improve this situation is to use a combination of longer shackles and a relocated shackle mount. After a bit of forum searching, I decided to go with shackles 7.25" from center to center on the bolt holes. Now, understand that this is not the correct way to determine the proper shackle length. I took what other people had done, what worked for them and emulated it... but the proper way to do this is to:

1) Measure your springs length when the main leaf is flat.
2) Use your measuring tape set to that length, running from the front hanger bolt hole towards the frame behind your shackle mount to determine where the spring eye will be relative to the frame/shackle when the spring is at its longest and mark it.
3) Measure from your shackles pivot point on the frame to the spring eye position you just measured/marked. 

The result, plus ¼" for a fudge factor, is how long your shackles need to be center to center on its bolt holes. I didn't develop or even use this method myself. Credit for it goes to rcurrier44, his post on pirate4x4.com's Chevy forum was very informative.

Shackles this long should be made of thick steel, not less than than 3/8". Some people recommend adding a cross member between the shackle plates to form an H-shaped shackle. I'm not an automotive engineer or a materials expert so I'll leave that decision up to you. The 7.25" eye to eye shackles are about 2.75" longer than the ORD shackles I ran previously, they are long, but I'm not too worried about it. It'd be no problem to add a cross member to them later if I choose to do so. I got my shackles from Black Widow Performance (http://www.blackwidowperformance.com). They are 3/8", CNC machined, primered and have BWP's trick spider logo machined into them. All I had to do was give them a quick zap of bling rattle can paint and they were ready to install.

BWP Shackles

To relocate the shackle mount, its time to remove some more rivets, four hold each one to the frame. Thankfully, these are easier to get to with a grinder than the ones we had to remove for the front hangers. I relocated mine by aligning the bottom-right hole in the bracket with the bottom-left hole in the frame (as seen from the driver's side of the vehicle). I then rotated the bracket clockwise about the hole in the frame until there was enough clearance between the lower-left hole in the bracket and the frame for the nut to fit on the bolt. I then used the bracket as a template to drill the other 3 bolt holes.

Before you drill anything though, note that there are fuel lines running inside the frame rail on the passenger side. Make sure you take measures to keep them out of the way before you drill any holes on that side. To remount the bracket you'll need a metal hole saw and a drill to cut a new hole in the frame. The factory hole is 2" in diameter. I used a Blu-Mol 1.75" hole saw, mainly because it was what I had on-hand (http://blumol.net). The part of the shackle hanger that sticks through the frame is roughly 1.625" in diameter so, in theory, a 1-5/8" hole saw would work. The thing is, I found it difficult, even using the bracket as a guide, to cut the hole in the frame in exactly the right spot. This made the use of a 1.75" saw a good thing as it provided a little bit of wiggle room. It is also smaller than the factory hole so it shouldn't weaken the frame any more than the original did. The only good reason to cut a hole as large as the factory one would be if you want to weld the disc of steel you remove back into the factory frame hole, which isn't a bad idea.

In any case, the end result is a bracket that is approximately 2.75" further forward on the frame than stock. If your frame is as dirty/grimy as mine is, you might take this opportunity to clean it up before you bolt everything together, the shackle hangers don't come off very often, might as well clean/prime/paint under them while you have the chance. Once the paint is dry, install the shackle hangers with eight more grade 8 bolts (1.25" x 7/16"), washers and locking nuts and you're set. If you haven't replaced the frame hanger bushing before, now is a great time to do it. I had bushings from ORD in there and a quick inspection found the passenger side one to be in three pieces, so I got a new pair. With the new bushings installed and the rear hangers in place the hard part is over and its time to start piecing the suspension back together.

Rivets to remove 3Rear Hanger Removed
Rear Hanger Bolted onDead Bushing

Before we install the springs, let's consider their fasteners for a minute. From the factory, K5s use a 9/16" bolt in the front spring eye. In the rear shackle/spring eye and frame bushing they used 7/16". Not exactly sure what the logic was there... perhaps a rear-of-the-spring failure is preferable to a front-of-the-spring one for safety reasons, so they used the weaker ones there. Many CK5'ers, myself included, have replaced those 7/16" bolts with 1/2" greasable bolts from ORD. These have served me well, but the new bushings I got had sleeves for 9/16" bolts in both spring eyes, so I pondered running 9/16" for all three (front, lower shackle, upper shackle). A quick CK5 forum search revealed that using larger than 1/2" bolts in the frame-mounted upper bushing might require a new mount and some fab work.

At the time, I wanted to get the rig ready for some summer wheelin', so I decided to go to 9/16" bolts in the lower shackle and stick with 1/2" stuff up top. Eventually, I'll probably go to 9/16" all around. It can be done with a custom shackle hanger or by drilling out a standard frame bushing to ¾" ID for the larger bolt sleeve. In any case, BWP machined my shackles for me and a trip to the hardware store yielded new bolts. The ones I bought are 5.5" long. These are ½" longer than stock, which places the shear forces fully on the shank, instead of loading them on the threads like the factory bolts. I'm not an engineer, but loading a bolt that way never seemed like a good idea to me. The exception was the passenger side frame-bushing bolt. My custom exhaust system was in the way... it wouldn't allow for such a long bolt to be used, for the time being I'll make due with a 5" long one until I can adjust the exhaust system.

The hard part is over, time to start putting everything back together. Bolt the shackles to the frame. Then, rest the spring pack on top of the axle. This helps hold the packs weight while you line things up. Once things are aligned, bolt the front spring eye to the front hanger. Keep the nuts finger loose so you can wiggle things a bit to ease assembly. Rotate the rear of the spring up and bolt it to the shackle. Now comes the fun part. Moving the hangers the way we have, the front axle will have to be moved forward. This means you're going to have to man-handle the axle around and try to get the center pins lined up with the holes in the spring perches so you can get everything bolted back together.

If you have friends, this may be a good time to buy some beer and pizza. Personally, I'm a loner and always seem to be working on this kind of thing by myself. A floor jack comes in really handy here. It's not hard moving an axle, even a heavy bastard like the D60, with a good floor jack. Getting everything to line up just right though, so the center pins go in the perches correctly, can take a little time and more than a few aggravated grunts and groans. I've often found that getting it close, lifting the axle up with the jack, and then gently rocking the axle back and forth helps the pins find their way "home". Then it's just a matter of reinstalling the u-bolts (torque spec: 140 ft/lbs) and tires/wheels. Once the rig is back on its feet, bust out the measuring tape to see how its current stance compares with what you started with. If nothing else, you'll be able to answer the ubiquitous "hey man, how much lift does that thing got?" question on trail runs. Personally, I didn't bother to measure... IMO, if the tires fit under max compression, the answer to that question is "enough". Just eyeballing it though, I'd say I got 4-4.5".

Before 1After 1
Before 2After 2

Ok, your rig is back on it's feet with the new springs! Before you go out and wheel the heck out of it though, keep in mind that brake line, drive shaft, and shock length may need to be addressed... as will drag link length and new shock mounting. What about bump stops and limiting straps? Stay tuned for Part III of my swap write-up, where I show step-by-step how I addressed all of these issues on my K5!

For this upgrade I used the following tools and materials. It can certainly be done with other tools (and it'd be much easier!) and/or different parts, but this is what I used.

Tools:

4.5" angle grinder (flapper, cutoff and grinder wheels)
Multi-speed electric drill (1/4, 3/8 and 7/16" bits)
Wrenches/sockets (3/4", 13/16", 11/16", 5/8", 7/8", 9/16")
Center punch
Large flat screw driver
3-1/2 ton floor jack
3 ton jack stands x 4
Needle nose pliers
Crowbar
BFH

Hardware/parts/etc:

9/16"x5" center pins/nuts x 2
7/16" x 1.25" SAE grade 8 bolts and metal locking nuts x 8 (shackle hanger hardware)
7/16" x 1" bolts w/ metal locking nuts x 16 w/ hardened washers (front spring mount hardware)
9/16" x 5.5" bolts x 4, all metal locking nuts x 4, hardened washers x (spring eye hardware) 
1/2" x 5.5" bolts x 2, all metal locking nuts x 2, hardened washers x (upper shackle hardware)
Poly bushings x 4
UHMW-PE tape, 3" wide, approx. 25'
Black Widow Performance shackles
Krylon "True Blue" rattle can paint
Walmart cheapo rattlecan gloss black
Rustoleum Grey Auto Primer
1.75" Blu-Mol bi-metal hole saw

Chevy Blazer specifications

All tables are for 4x4 Blazers only and do not include 2x4 or GMC Jimmy

(M)=manual transmission  (A)=automatic transmission *=see notes

Choose model year below to see specifications.
19911990198919881987198619851984
19831982198119801979197819771976
1975197419731972197119701969 

 

 

Year: 1991Production Total: 7,332
Base Price: 17,590Weight: 4,507
Wheel Base: 106.5 in.Fuel Tank Capacity: 26-gallon/31- gallon
Length: 184.8 in.Height: 73.4 in.
Std. Engine, (HP):

OHV Eight-cylinder 350 cid. (210) @ 4000 rpm

Opt. Engine, (HP):

OHV Diesel Eight-cylinder 379 cid. (130) @ 3600 rpm

Rear Axle:

GM Corporate 10-bolt (8.5-in. 1.28 Axle Dia. 30 Spline)

Front Axle:

GM Corporate 10-bolt (8.5-in. 1.28 Axle Dia. 30 Spline)

Transmission (M):

SM465 4 spd. (6.55:1 First Gear)

Transmission (A):

4L60 * (3.06:1 First Gear)

Transfer Case (M):

NP241 (2.72:1 Low Range)

Transfer Case (A):

NP241 (2.72:1 Low Range)

Notes:

* The 700R4 was re-named to 4L60 in 1991.

The TBI (throttle body injection) system used on the Blazer's standard 5.7-liter V-8 had longer throttle shaft bearings, new throttle return springs, and improved fuel mixture distribution.  The 5.7-liter V-8 also had new heavy-duty intake valves and powdered metal camshaft sprockets.

Standard on all engines was a lighter more powerful 100-amp CS130 alternator.

Two new exterior colors, Brilliant Blue and Slate Metallic were offered.

Blazers featured a steel half-cab with an integral roll bar built into the steel front compartment roof and lock pillar structures.

 

 

Year: 1990Production Total: 18,921
Base Price: 16,485Weight: 4,839
Wheel Base: 106.5 in.Fuel Tank Capacity: 26-gallon/31- gallon
Length: 184.8 in.Height: 73.4 in.
Std. Engine, (net HP):

OHV Eight-cylinder 350 cid. (210) @ 4000 rpm

 

 

Opt. Engine, (net HP):

OHV Diesel Eight-cylinder 379 cid. (130) @ 3600 rpm

OHV Diesel Eight-cylinder 379 cid. (148) @ 3600 rpm

Rear Axle:

GM Corporate 10-bolt (8.5-in. 1.28 Axle Dia. 30 Spline)

Front Axle:

GM Corporate 10-bolt (8.5-in. 1.28 Axle Dia. 30 Spline)

Transmission (M):

SM465 4 spd. (6.55:1 First Gear)

Transmission (A):

TH700-R4 (3.06:1 First Gear)

Transfer Case (M):

NP241 (2.72:1 Low Range)

Transfer Case (A):

NP241 (2.72:1 Low Range)

Notes:

All Blazers now had a standard rear wheel antilock braking system.

A new electronic speedometer was also introduced for 1990, along with non-asbestos brake linings.

The Blazer body also used double sided, galvanized exterior sheet metal.

The 5.7-liter V-8 (L05) engine was improved for 1990 with the addition of improved oil control rings, a redesigned rear crankshaft seal, a new camshaft sprocket design, non-asbestos intake manifold gaskets, and heavy-duty intake valves.

Blazers featured a steel half-cab with an integral roll bar built into the steel front compartment roof and lock pillar structures.

 

 

Year: 1989Production Total: 26,663
Base Price: 15,965Weight: 4,878
Wheel Base: 106.5 in.Fuel Tank Capacity: 26-gallon/31- gallon
Length: 184.8 in.Height: 73.4 in.
Std. Engine, (net HP):

OHV Eight-cylinder 350 cid. (210) @ 4000 rpm

 

 

Opt. Engine, (net HP):

OHV Diesel Eight-cylinder 379 cid. (130) @ 3600 rpm

OHV Diesel Eight-cylinder 379 cid. (148) @ 3600 rpm

Rear Axle:

GM Corporate 10-bolt (8.5-in. 1.28 Axle Dia. 30 Spline)

Front Axle:

GM Corporate 10-bolt (8.5-in. 1.28 Axle Dia. 30 Spline)

Transmission (M):

SM465 4 spd. (6.55:1 First Gear)

Transmission (A):

TH700-R4 (3.06:1 First Gear)

Transfer Case (M):

NP241 (2.72:1 Low Range)

Transfer Case (A):

NP241 (2.72:1 Low Range)

Notes:

The 1989 Blazer had new base and up-level grilles, as well as new headlight bezels and new body side moldings, and bumper rub strips.

Corporate 10-bolt axles were upgraded to 30 spline axle shafts from previous 28 spline (1989-91).

New for 1989 was the introduction of an all-new base coat/clear coat paint.

The L05 5.7-liter V-8 now had serpentine accessory drive belts in place of the older multi-belt accessory drive.

Blazers featured a steel half-cab with an integral roll bar built into the steel front compartment roof and lock pillar structures.

 

 

Year: 1988Production Total: 28,446
Base Price: 14,509Weight: 4,676
Wheel Base: 106.5 in.Fuel Tank Capacity: 26-gallon/31-gallon
Length: 184.8 in.Height: 73.4 in.
Std. Engine, (net HP):

OHV Eight-cylinder 350 cid. (210) @ 4000 rpm

 

 

Opt. Engine, (net HP):

OHV Diesel Eight-cylinder 379 cid. (130) @ 3600 rpm

OHV Diesel Eight-cylinder 379 cid. (148) @ 3600 rpm

Rear Axle:

GM Corporate 10-bolt (8.5-in. 1.28 Axle Dia. 28 Spline)

Front Axle:

GM Corporate 10-bolt (8.5-in. 1.28 Axle Dia. 28 Spline)

Transmission (M):

SM465 4 spd. (6.55:1 First Gear)

Transmission (A):

TH700-R4 (3.06:1 First Gear)

Transfer Case (M):

NP208 (2.61:1 Low Range)

NP241 (2.72:1 Low Range)

Transfer Case (A):

NP208 (2.61:1 Low Range)

NP241 (2.72:1 Low Range)

Notes:

Four new colors were introduced for 1988: Bright Blue Metallic, Forest Green Metallic, Light Mesa Brown Metallic, and Dark Mesa Brown Metallic.

New features for 1988 include a fixed mast antenna in place of the old windshield antenna, a trip odometer as part of the gauge package cluster, and an improved pulse windshield wiper control.

Helping to reduce air leaks in the doors was a new door handle seal.

Blazers featured a steel half-cab with an integral roll bar built into the steel front compartment roof and lock pillar structures.

 

 

Year: 1987Production Total: 32,437
Base Price: 13,066Weight: 4,379
Wheel Base: 106.5 in.

 

Fuel Tank Capacity:

94 liter (24.83-gallon)/117 liter (31-gallon)

Length: 184.8 in.Height: 73.4 in.
Std. Engine, (HP):

OHV Eight-cylinder 350 cid. (210) @ 4000 rpm

 

 

Opt. Engine, (HP):

OHV Diesel Eight-cylinder 379 cid. (130) @ 3600 rpm

OHV Diesel Eight-cylinder 379 cid. (148) @ 3600 rpm

Rear Axle:

GM Corporate 10-bolt (8.5-in. 1.28 Axle Dia. 28 Spline)

Front Axle:

GM Corporate 10-bolt (8.5-in. 1.28 Axle Dia. 28 Spline)

Transmission (M):

SM465 4 spd. (6.55:1 First Gear)

Transmission (A):

TH700-R4 (3.06:1 First Gear)

Transfer Case (M):

NP208 (2.61:1 Low Range)

Transfer Case (A):

NP208 (2.61:1 Low Range)

Notes:

New for 1987 was the TBI (throttle body injection) fuel injection system.

Blazers featured a steel half-cab with an integral roll bar built into the steel front compartment roof and lock pillar structures.

 

 

Year: 1986Production Total: 37,310
Base Price: 12,034Weight: 4,444
Wheel Base: 106.5 in.

 

Fuel Tank Capacity:

94 liter (24.83-gallon)/117 liter (31-gallon)

Length: 184.8 in.Height: 73.4 in.
Std. Engine, (net HP):

OHV Six-cylinder 262 cid. (155) @ 4000 rpm

 

 

 

 

 

 

 

 

 

Opt. Engine, (net HP):

OHV Eight-cylinder 305 cid. (155) @ 4000 rpm

OHV Eight-cylinder 305 cid. (160) @ 4400 rpm

OHV Eight-cylinder 350 cid. (160) @ 3800 rpm

OHV Eight-cylinder 350 cid. (165) @ 3800 rpm

OHV Eight-cylinder 350 cid. (185) @ 4000 rpm

OHV Diesel Eight-cylinder 379 cid. (130) @ 3600 rpm

OHV Diesel Eight-cylinder 379 cid. (148) @ 3600 rpm

Rear Axle:

GM Corporate 10-bolt (8.5-in. 1.28 Axle Dia. 28 Spline)

Front Axle:

GM Corporate 10-bolt (8.5-in. 1.28 Axle Dia. 28 Spline)

Transmission (M):

SM318/SM326/SM330/T-89A/T-150 3 spd. (2.47-3.50:1 First Gear)

SM465 4 spd. (6.55:1 First Gear)

Transmission (A):

TH700-R4 (3.06:1 First Gear)

 

Transfer Case (M):

NP208 (2.61:1 Low Range)

Transfer Case (A):

NP208 (2.61:1 Low Range)

Notes:

Blazers for 1986 had new molded front bucket seats with folding seat backs.

Three new paint colors, Canyon Copper Metallic, Nevada Gold Metallic, and Steel Gray Metallic were released.

A body color panel between upper, and lower grilles, and the grilles had only a single horizontal bar intersected by seven vertical bars.  The headlight housing had a vertical look with rectangular lamps  stacked atop each other again.  An amber-colored parking lamp was standard on the bottom, but when halogen high-beams were ordered, the parking lamps moved behind the lower grille.

First year for the one piece rear main engine seal making this model year engine non interchangeable with Blazers of older vintage without changing flywheel etc...

Blazers featured a steel half-cab with an integral roll bar built into the steel front compartment roof and lock pillar structures.

 

 

Year: 1985Production Total: 40,011
Base Price: 11,223Weight: 4,462
Wheel Base: 106.5 in.

 

Fuel Tank Capacity:

94 liter (24.83-gallon)/117 liter (31-gallon)

Length: 184.8 in.Height: 73.4 in.
Std. Engine, (net HP):

OHV Six-cylinder 262 cid. (155) @ 4000 rpm

 

 

 

 

 

 

 

 

Opt. Engine, (net HP):

OHV Eight-cylinder 305 cid. (150) @ 4000 rpm

OHV Eight-cylinder 305 cid. (160) @ 4400 rpm

OHV Eight-cylinder 350 cid. (160) @ 3800 rpm

OHV Eight-cylinder 350 cid. (165) @ 3800 rpm

OHV Diesel Eight-cylinder 379 cid. (130) @ 3600 rpm

OHV Diesel Eight-cylinder 379 cid. (151) @ 3600 rpm

Rear Axle:

GM Corporate 10-bolt (8.5-in. 1.28 Axle Dia. 28 Spline)

Front Axle:

GM Corporate 10-bolt (8.5-in. 1.28 Axle Dia. 28 Spline)

Transmission (M):

SM318/SM326/SM330/T-89A/T-150 3 spd. (2.47-3.50:1 First Gear)

SM465 4 spd. (6.55:1 First Gear)

Transmission (A):

TH350 (2.52:1 First Gear)

TH700-R4 (3.06:1 First Gear)

 

Transfer Case (M):

NP208 (2.61:1 Low Range)

Transfer Case (A):

NP208 (2.61:1 Low Range)

Notes:

The 1985 Blazers had much wider body color panel between upper, and lower grilles, and the grilles had only a single horizontal bar intersected by seven vertical bars.  The headlight housing had more of a vertical look than last year's, although the rectangular lamps were stacked atop each other again.  An amber-colored parking lamp was standard on the bottom, but when halogen high-beams were ordered, the parking lamps moved behind the lower grille.

Blazers featured a steel half-cab with an integral roll bar built into the steel front compartment roof and lock pillar structures.

 

 

Year: 1984Production Total: 39,329
Base Price: 10,819Weight: 4,409
Wheel Base: 106.5 in.Fuel Tank Capacity:

24-gallon/94 liter (24.83-gallon)/31-gallon

Length: 184.8 in.Height: 73.4 in.
Std. Engine, (net HP):

OHV Six-cylinder 250 cid. (115) @ 3600 rpm

 

 

 

Opt. Engine, (net HP):

OHV Eight-cylinder 305 cid. (160) @ 4400 rpm

OHV Eight-cylinder 350 cid. (165) @ 3800 rpm

OHV Diesel Eight-cylinder 379 cid. (130) @ 3600 rpm

Rear Axle:

GM Corporate 10-bolt (8.5-in. 1.28 Axle Dia. 28 Spline)

Front Axle:

GM Corporate 10-bolt (8.5-in. 1.28 Axle Dia. 28 Spline)

Transmission (M):

SM318/SM326/SM330/T-89A/T-150 3 spd. (2.47-3.50:1 First Gear)

SM465 4 spd. (6.55:1 First Gear)

Transmission (A):

TH350 (2.52:1 First Gear)

TH700-R4 (3.06:1 First Gear)

 

Transfer Case (M):

NP208 (2.61:1 Low Range)

Transfer Case (A):

NP208 (2.61:1 Low Range)

Notes:

A bold new grille had a bi-level design with three black-finished horizontal bars, square headlamps in both sections (optional), parking lamps behind the bars on the bottom, and a yellow bow tie on the body color strip in the middle.

Only 4x4 models were available for 1984.

Fender badges now identified these trucks as K5 models.

Blazers featured a steel half-cab with an integral roll bar built into the steel front compartment roof and lock pillar structures.

 

 

Year: 1983Production Total: 26,245
Base Price: 10,287Weight: 4,426
Wheel Base: 106.5 in.Fuel Tank Capacity: 24-gallon/31-gallon
Length: 184.8 in.Height: 73.4 in.
Std. Engine, (net HP):

OHV Six-cylinder 250 cid. (120) @ 4000 rpm

 

 

 

Opt. Engine, (net HP):

OHV Eight-cylinder 305 cid. (165) @ 4400 rpm

OHV Eight-cylinder 350 cid. (165) @ 3800 rpm

OHV Diesel Eight-cylinder 379 cid. (130) @ 3600 rpm

Rear Axle:

GM Corporate 10-bolt (8.5-in. 1.28 Axle Dia. 28 Spline)

Front Axle:

GM Corporate 10-bolt (8.5-in. 1.28 Axle Dia. 28 Spline)

Transmission (M):

SM318/SM326/SM330/T-89A/T-150 3 spd. (2.47-3.50:1 First Gear)

SM465 4 spd. (6.55:1 First Gear)

Transmission (A):

TH350 (2.52:1 First Gear)

TH700-R4 (3.06:1 First Gear)

 

Transfer Case (M):

NP208 (2.61:1 Low Range)

Transfer Case (A):

NP208 (2.61:1 Low Range)

Notes:

The Blazer had a revised grille for 1983, it featured a blacked-out appearance.  Parking lights were moved from the bumper to bottom of the grille and the horizontal center-bar was finished in body color.

Blazers featured a steel half-cab with an integral roll bar built into the steel front compartment roof and lock pillar structures.

 

 

Year: 1982Production Total: 24,514
Base Price: 9,874Weight: 4,294
Wheel Base: 106.5 in.Fuel Tank Capacity: 24-gallon/31-gallon
Length: 184.8 in.Height: 73.4 in.
Std. Engine, (net HP):

OHV Six-cylinder 250 cid. (110) @ 3600 rpm

 

 

 

Opt. Engine, (net HP):

OHV Eight-cylinder 305 cid. (160) @ 4400 rpm

OHV Eight-cylinder 350 cid. (165) @ 3800 rpm

OHV Diesel Eight-cylinder 379 cid. (130) @ 3600 rpm

Rear Axle:

GM Corporate 10-bolt (8.5-in. 1.28 Axle Dia. 28 Spline)

Front Axle:

GM Corporate 10-bolt (8.5-in. 1.28 Axle Dia. 28 Spline)

Transmission (M):

SM318/SM326/SM330/T-89A/T-150 3 spd. (2.47-3.50:1 First Gear)

SM465 4 spd. (6.55:1 First Gear)

Transmission (A):

TH350 (2.52:1 First Gear)

TH700-R4 (3.06:1 First Gear)

Transfer Case (M):

NP208 (2.61:1 Low Range)

Transfer Case (A):

NP208 (2.61:1 Low Range)

Notes:

New for 1982 Blazers was a 6.2-liter (379-cid) Chevrolet-built diesel V-8 and four-speed overdrive transmission, both costing extra.

Blazers featured a steel half-cab with an integral roll bar built into the steel front compartment roof and lock pillar structures.

 

 

Year: 1981Production Total: 23,635
Base Price: 8,856Weight: 4,087
Wheel Base: 106.5 in.Fuel Tank Capacity: 24-gallon/31-gallon
Length: 184.8 in.Height: 73.4 in.
Std. Engine, (net HP):

OHV Six-cylinder 250 cid. (115) @ 3600 rpm

 

 

 

Opt. Engine, (net HP):

OHV Eight-cylinder 305 cid. (130) @ 4000 rpm

OHV Eight-cylinder 305 cid. (160) @ 4400 rpm

OHV Eight-cylinder 350 cid. (165) @ 3600 rpm

Rear Axle:

GM Corporate 12-bolt (8.7/8-in. 1.31 Axle Dia. 30 Spline)

GM Corporate 10-bolt (8.5-in. 1.28 Axle Dia. 28 Spline)

Front Axle:

GM Corporate 10-bolt (8.5-in. 1.28 Axle Dia. 28 Spline)

Transmission (M):

SM318/SM326/SM330/T-89A/T-150 3 spd. (2.47-3.50:1 First Gear)

SM465 4 spd. (6.55:1 First Gear)

Transmission (A):

TH350 (2.52:1 First Gear )

 

Transfer Case (M):

NP208 (2.61:1 Low Range)

Transfer Case (A):

NP208 (2.61:1 Low Range)

Notes:

Blazers for 1981 had an aerodynamically restyled front end.  The smoother new hood and fenders, together with a front bumper mounted air dam, were designed to improve fuel economy.  A new grille continued the ice-cube-tray look with 16 taller openings running across the Blazer between the stacked square headlamps.  A wide center horizontal molding - bright-finished with a bow tie in the middle - spanned the full width of the front end.

Rectangular parking lamps/turn signals were placed in the new front bumper, directly beneath the headlamps.

On the body sides, the belt-level feature line ran the length of the Blazer, and blended more smoothly into the fender edge at the front.  Two-tone paint treatments were now separated at the lower perimeter feature line.

Blazer 4x4 models had a new aluminum transfer case and automatic locking hubs.

A new front quad shock package was available.

Blazers featured a steel half-cab with an integral roll bar built into the steel front compartment roof and lock pillar structures.

 

 

Year: 1980Production Total: 31,776
Base Price: 8,233Weight: 4,429
Wheel Base: 106.5 in.Fuel Tank Capacity: 24-gallon/31-gallon
Length: 184.8 in.Height: 73.4 in.
Std. Engine, (net HP):

OHV Six-cylinder 250 cid. (130) @ 3800 rpm

 

 

 

 

 

Opt. Engine, (net HP):

OHV Eight-cylinder 305 cid. (130) @ 4000 rpm

OHV Eight-cylinder 350 cid. (165) @ 3600 rpm

OHV Eight-cylinder 350 cid. (170) @ 3800 rpm

OHV Eight-cylinder 400 cid. (185) @ 3600 rpm

Rear Axle:

GM Corporate 12-bolt (8.7/8-in. 1.31 Axle Dia. 30 Spline)

Front Axle:

GM Corporate 10-bolt (8.5-in. 1.28 Axle Dia. 28 Spline)

Transmission (M):

SM318/SM326/SM330/T-89A/T-150 3 spd. (2.47-3.50:1 First Gear)

SM465 4 spd. (6.55:1 First Gear)

Transmission (A):

TH350 (2.52:1 First Gear)

TH400 (2.48:1 First Gear)

Transfer Case (M):

NP205 (1.96:1 Low Range)

Transfer Case (A):

NP205 (1.96:1 Low Range)

Notes:

Blazers had a new Argent colored grille with 33 square openings and new gauges with international symbols.

A Silverado package was now available and included rectangular headlamps, a chromed grille and larger parking lamps, plus custom cloth or Brahman-grain vinyl interiors.

The 305-cid and 400-cid V-8s were dropped.

A popular new option was styled aluminum wheels.

Blazers featured a steel half-cab with an integral roll bar built into the steel front compartment roof and lock pillar structures.

 

 

Year: 1979Production Total: 90,987
Base Price: 7,373Weight: 4,371
Wheel Base: 106.5 in.Fuel Tank Capacity: 24-gallon/31-gallon
Length: 184.8 in.Height: 73.4 in.
Std. Engine, (net HP):

OHV Six-cylinder 250 cid. (130) @ 3800 rpm

 

 

 

Opt. Engine, (net HP):

OHV Eight-cylinder 305 cid. (130) @ 4000 rpm

OHV Eight-cylinder 350 cid. (165) @ 3600 rpm

OHV Eight-cylinder 400 cid. (185) @ 3600 rpm

Rear Axle:

GM Corporate 12-bolt (8.7/8-in. 1.31 Axle Dia. 30 Spline)

Front Axle:

GM Corporate 10-bolt (8.5-in. 1.28 Axle Dia. 28 Spline)

Transmission (M):

SM318/SM326/SM330/T-89A/T-150 3 spd. (2.47-3.50:1 First Gear)

SM465 4 spd. (6.55:1 First Gear)

Transmission (A):

TH350 (2.52:1 First Gear)

TH400 (2.48:1 First Gear)

Transfer Case (M):

NP205 (1.96:1 Low Range)

Transfer Case (A):

NP203 (2.01:1 Low Range)

Notes:

Blazers featured a steel half-cab with an integral roll bar built into the steel front compartment roof and lock pillar structures.

GM added a fuel door to the passenger side rear quarter panel, previously, they had external gas caps.

 

 

Year:: 1978Production Total: 88,858
Base Price: 6,397Weight: 3,928
Wheel Base: 106.5 in.Fuel Tank Capacity: 20-gallon/31-gallon
Length: 184.8 in.Height: 73.4 in.
Std. Engine, (net HP):

OHV Six-cylinder 250 cid. (115) @ 3800 rpm

 

 

 

Opt. Engine, (net HP):

OHV Eight-cylinder 305 cid. (130) @ 4000 rpm

OHV Eight-cylinder 350 cid. (165) @ 3800 rpm

OHV Eight-cylinder 400 cid. (175) @ 3600 rpm

Rear Axle:

GM Corporate 12-bolt (8.7/8-in. 1.31 Axle Dia. 30 Spline)

 

Front Axle:

Dana 44 (8.5-in.  1.31 Axle Dia. 30 Spline)

GM Corporate 10-bolt (8.5-in. 1.28 Axle Dia. 28 Spline)

Transmission (M):

SM318/SM326/SM330/T-89A/T-150 3 spd. (2.47-3.50:1 First Gear)

SM465 4 spd. (6.55:1 First Gear)

Transmission (A):

TH350 (2.52:1 First Gear)

TH400 (2.48:1 First Gear)

Transfer Case (M):

NP205 (1.96:1 Low Range)

Transfer Case (A):

NP203 (2.01:1 Low Range)

Notes:

For 1978 the instrument panel trim and nameplate were changed.  There was a deluxe instrument panel option with black-textured center section for Custom Deluxe models, and bright brush finish for Cheyennes.

Also new was a redesigned rear compartment entry/exit system, a new rear folding seat, and a flatter floor panel behind the seat for extra leg room.  The frame was changed to position the body mounts outside of the frame to allow for the new rear seat design.

Blazers featured a steel half-cab with an integral roll bar built into the steel front compartment roof and lock pillar structures.

 

 

<
Year:: 1977Production Total: 86,838
Base Price: 5,603Weight: 4,268
Wheel Base: 106.5 in.Fuel Tank Capacity: 20-gallon/31-gallon
Length: 184.5 in.Width: 71 in.
Std. Engine, (net HP):

OHV Six-cylinder 250 cid. (110) @ 4800 rpm

 

 

 

Opt. Engine, (net HP):

OHV Eight-cylinder 305 cid. (130) @ 4000 rpm

OHV Eight-cylinder 350 cid. (145) @ 3800 rpm

OHV Eight-cylinder 400 cid. (175) @ 3600 rpm

Rear Axle:

GM Corporate 12-bolt (8.7/8-in. 1.31 Axle Dia. 30 Spline)

 

Front Axle:

Dana 44 (8.5-in. 1.31 Axle Dia. 30 Spline)

GM Corporate 10-bolt (8.5-in. 1.28 Axle Dia. 28 Spline)

Transmission (M):

SM318/SM326/SM330/T-89A/T-150 3 spd. (2.47-3.50:1 First Gear)

SM465 4 spd. (6.55:1 First Gear)

Transmission (A):

TH350 (2.52:1 First Gear)

TH400 (2.48:1 First Gear)

Transfer Case (M):

NP205 (1.96:1 Low Range)

Transfer Case (A):

NP203 (2.01:1 Low Range)