OT: Changing gears in rearend on Chevy Suburban K1500

OK guys, how easy is it to change the gears out in a rearend. I have finally determined what my problem is on my Suburban. There are some parts of the teeth missing on the ring, don't know about the pinion, but going to change both anyway. What all should I replace when doing this, need to get it done asap, as I'm returning to work on Wednesday from disability leave. Please help if you can, don't need a bunch of negative comments like "take it to the shop", because if I could have afforded it, it would already be there.

First make sure you are getting the same gear ratio as what was in there.
Second; if you don't know how -have someone else "load it." - Meaning there is a certain amount of tightness to use and if you get it wrong you will have a howling rear end because the gears aren't meshing right.
I just bought a 1998 1500 4X4 four 1500.00 because the previous owner didn't get it right.

Generally, the ring and pinion come as a matched set. Check all bearings for wear, if they are still in good shape you should be able to re-use them. It is advisable to replace all bearings and seals when you do a ring and pinion, but if you are on a tight budget you can probably get by. Good luck.

It's not that bad to do. When you remove the old pinion, save and reuse the shim under the inner bearing. You will need some marking compound to check the tooth contact pattern. You want to get a contact patch centered on the tooth. Reusing the shim on the pinion usually gets the depth right. From there you set the preload on the carrier bearings and you may need to add to one side and subtract from the other to get the preload on the bearings right and the side to side depth on the gears.

You will need to replace the ring and pinion gears as a set. You will also need to replace the bearings for both the carrier and pinion. You can buy a bearing kit that includes bearings, pinion seal, shims, crush sleeve and ring gear bolts for about 100 bucks. The ring and pinion gear set will cost around 150. While you're at it, if it doesn't already have a locking differential, you should plan on replacing it. That will be the most expensive item, at around 400 bucks, but replacing the differential solves the problem of removing the ring gear and carrier bearings, which aren't easy to remove if you don't have the right tools. If the vehicle has over 100K on it, you should probably replace the wheel bearings and seals, which will total around 100 bucks.

Tools:
Foot-lb torque wrench (needs to work both clockwise and counter-clockwise)
Inch-lb torque wrench (for pinion bearing preload)
Dial indicator (for adjusting gear backlash).
Impact wrench, or 1/2" or 3/4" drive ratchet with big cheater bar (pinion nut needs about 300 ft-lbs to crush the sleeve)
Slide hammer (if you're replacing the wheel bearings)
Carrier bearing puller (if you're NOT replacing the differential)
Gas barbecue (to heat the ring bearing prior to installation; kitchen oven also works if you're a bachelor)
Pipe wrench with big cheater bar (to hold the pinion yoke while setting preload)

If you've read this far and still think you want to tackle it, here are some tips:
1. Technically, you're supposed to set the pinion depth, which requires a special fixture. In practice, you can get away with just re-using the old pinion shim stack.
2. The ring gear bolts are left-hand thread.
3. The ring gear must be heated in order to remove it or install it on the differential carrier. 500 degrees F is a good, safe temperature.
4. Setting the pinion preload is very tricky, because once you crush the preload sleeve it can't be uncrushed. As you approach the desired preload, tighten the pinion in very small increments. If you overshoot the target preload, leave it be.
5. Pack the bearings with grease prior to installation. You need lubrication to set the preload properly, and they'll break in a bit in the first few miles.

You WILL need a manual, because nobody is going to tell you all the steps. Check out the DTS site below, you can find all the parts you'll need there, even if you end up buying them locally. Good luck.
Drive Train Specialists

Figure out the gear ratio as suggested above, then try a junkyard for a complete rearend with the same gears. Quickest and easiest if they have one.

I agree. That's the quickest and simplest, and probably the cheapest.

You'll need to check your ratios, but I think you'll save yourself a lot of headache by getting a complete rear axle from a salvage yard and just replacing it as a unit. Probably cheaper than buying a new ring and pinion.
You'd have pretty much disassemble the entire axle, replace seals, set bearing preloads, backlash, etc. If you get it wrong, you could be throwing away those new parts.
Not a job for the average shade tree mechanic.

OK, sounds interesting. If I go with a used transmission, which years and models will interchange?

(quoted from post at 05:46:24 02/11/12) OK, sounds interesting. If I go with a used transmission, which years and models will interchange?

Click to expand...

One from a pickup should work too, the salvage yard probably has a parts book and can set you up.

If you are going to heat the bearings with a bbq place them in an oil bath and not laying on the bottom of the pan either. Get them too hot and they are ruined. Seen it happen more than once.

OK, I'm going to go with a used rearend. Now just need to find one for the right price.

You may have a problem finding a low mileage rear end. I know a lot of guys will replace a blown rear end with a used one that has 80K miles on it, figuring it only has to last another 20K, but that's not how I like to do things. Replacing the whole rear axle opens up a different can of worms. If you're in a part of the country where they salt the roads, getting the U-bolts loose without wrecking them can be a challenge. Ditto with the brake lines and parking brake cables.

Your real problem is that you're on a tight schedule. You really have only two days because most junk yards are closed on weekends; you probably can't get a ring and pinion before Monday, either. A shop that specializes in rear end work can easily knock this job out in a day and do it right. They will charge between three and five hundred bucks for labor. If you do the overhaul yourself, you'll end up spending a couple of hundred bucks on tools unless you (or a friend) has a well-equipped shop, and it will take you two or three days because you've never done the job before. If you do the rear end swap, it will take a day or two to find a replacement, and another day or two to swap it out. And this all assumes you have a second vehicle to drive so you can make runs to the parts store.

I know you're on a tight budget, but remember: Time equals money. If you can get by without the use of your vehicle for a few days, the shade tree mechanic route can save you a few hundred bucks. But if you really need this job done by Tuesday night, consider taking it to a shop.

I guess if you put it in a oil bath, you'll know it's too hot when the oil bursts into flames. Using a barbecue and watching to make sure the temperature stays below 500F is safer than heating with an acetylene torch, which is the standard shade-tree approach. But it is true that you'll wreck the ring gear if it gets much above 500F, and most gas barbecues can easily hit 600 degrees or more.

Takes quite a bit of skill and knowledge to replace a ring-and-pinion and get it set up correctly. You have to get the pinion depth into ring-gear correct, ring-carrier bearing preload correct, pinion bearings preload correct, etc. You'd be way ahead to find a complete good rear for $50 or $100. Just keep in mind that you need the brakes to match and probably the ratio also. Not all 1500 trucks have the same brakes even when same model and year - it all depends on the option package. Look at the RPO spec sheet and see what brake package you have. It will be a three digit code starting with "J" for most years.

There are many brand new military surplus rears for sale for $200. But they only fit up to 1991 old-body style and have 3.08 ratios.

Most GM half-tons use roller bearings that ride directly on the axles -so make sure both axles feel tight. Axles and the pinion bearing are the areas that often go bad (or get ruined by a dumb "mechanics" when changing seals.

I've got many good 4WD Suburban rears here - but I doubt you're in my area. I also have no idea what year you have. I've got them up to 1991 with 3.08 and 3.42 ratios (for 1/2 tons) and several 3.73 and 4.10 for 3/4 ton Burbs.

What year is the truck?

Go to this National used-parts database. You might find just what you want not far from home (so no shipping will be involved). The site starts with the highest prices and works down - so make sure you scroll down to the lower prices.

Put year, make and part you want into this database search-engine:

http://car-part.com/

Just know what you are putting in there. I had a SW once that burned up the RE due to my accidental negligence.....out of oil.

I went to the junk yard and found a RE and figured it would work. Was pretty young at the time and not that moxy.

I installed it and I had the longest 2nd gear runout you ever saw but no low end torque to speak of. Apparently it was from an automatic transmission equipped vehicle and it had something like a 2.83:1 when I needed more like a 3.75ish ratio. My SW was stick shift.

Mark

You need a ring and pinion set I would also get a shim set and a I think they call it a master rebuild kit. Should come with all your bearings and seals. I would get a very good manual on doing this. I cant remeber if chevys use a crush sleeve on there rear ends or not but if they do have access to a large air compressor and you only get one shot at gettin it rite so do it in small incraments. Make darn sure you get it rite the first time or you will be doin all this again and spending alll the money again. I definatley would take the rearend completely out of the truck and work on it on a bench. Its alot easier to set your gears up this way. You can do it in the truck but its easier and better chance of not gettin your gear mesh off with it out. Just my opinion.

On the crush sleeve thing you mentioned. Somewhere in the back of my mind I seem to remember when you are putting the pinion nut on (the nut that holds the yoke on that accepts the yoke from the rear of the drive shaft where the rear U-joint is located) and doing the torque has to be to spec to crush this sleeve properly that Nickg mentioned. Otherwise you get this howl as you drive down the road.

Mark

Mark,

It's the PRELOAD that has to be in spec, not the torque. That is, holding the yoke from turning, you tighten the nut a bit, then let go of the yoke and check how many inch-pounds it takes to turn the pinion. The catch is that it takes around 300 ft-lbs to tighten the nut (because you're crushing the sleeve), yet preload is measured in inch-pounds. A sixteenth of a turn will take you from too loose to too tight. Too little preload and the pinion bearings will be loose once they break in. Too much preload and the bearings will fail.

Howling is typically caused by loose pinion bearings, although it can be because the backlash and/or pinion depth wasn't set up properly.

I don't know why it would be easier to set up the ring and pinion with the rear end off the vehicle. Removing the rear end is a fair amount of work, particularly if the vehicle has spent any winters in the Rust Belt.