May have to rebuild the rear differential on a stock 99 Tahoe 2 questions. How hard is it? Can the rear differential be changed in any way to get better gas mileage? The vehicle was given to me by a friend and only has 150k miles on it but i fell in love with it 1st time i drove it. Would like to keep it around as long as i can.
Rebuild rear differential
- Thread starter True2LSU
- Start date
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HiHoeSilver
Away!
Rebuilding the gears is a little tricky, but it's not rocket science. I have never done it, but plenty here have. Getting your shims and backlash adjusted is the hard part, I believe.
In terms of rehearing for milage gains....
1. What's in there now? Check the glove box for RPO codes. Most likely you will see GT4. That's the 3.73s. Next one down would be GU6, which is 3.42. Then GU5 (3.23) or GU4 (3.08).
2. Are you 4wd? If so, you would need to change the front diff, as well.
3. Do you tow? Taller gears will be better for towing.
4. Check for rpo code G80 as well to see if you have the locker.
Most people prefer the 3.73 or higher. The 3.42 and down get to be a little doggy. If you really need a rebuild, why not just find a good used one and swap it in?
Erickk120
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The trickiest part is interpreting the gear pattern correctly, assuming backlash is correct, and that there is some preload. too shallow will whine, too deep will whine, too tight of a backlash it will whine, to little it will whine.You get the idea, it only takes 1 of those to be off you will have noise.
I would only attempt it if you really want to learn to do diff stuff, otherwise just save the headache and get a used one as mentioned above, they are 150 bucks at my salvage yard.
You need some specialty tools, such as a magnetic base with an in dial indicator, quality calipers, I prefer analog over digital but thats just me. Lastly you need a beam style torque wrench. Might as well do a solid spacer instead of the crush sleeve while at it.
Last one I did was a ford 88, it has held about 30k miles and its still going.
Quality bearings is a must, Timken for me, you will need 4 pinion bearings so that you can make two set up bearings for the inner and outer pinion, that you can just slip shims in and out without having to re-press them, and the final permanent set, for when you have the correct depth shim selected.
Before any gear pattern check, make sure you have the correct backlash, while carrier preload isn't necessary for the set up part make sure everything has no play.
adding and removing backlash is tedious and you have to play with the carrier shims and it gets frustrating after a while.
Hope that gives you an idea, and most of the time the drive side is always silent if it had a semi decent/perfect pattern, the coast side tends to whine if not properly centered, so take extra time for that if you decided to tackle it.
Lastly if you have a g80 is probably about time to replace that pos, even though ironically I installed a new one in my GM10 bolt. Speak of hypocrites.
I would only attempt it if you really want to learn to do diff stuff, otherwise just save the headache and get a used one as mentioned above, they are 150 bucks at my salvage yard.
You need some specialty tools, such as a magnetic base with an in dial indicator, quality calipers, I prefer analog over digital but thats just me. Lastly you need a beam style torque wrench. Might as well do a solid spacer instead of the crush sleeve while at it.
Last one I did was a ford 88, it has held about 30k miles and its still going.
Quality bearings is a must, Timken for me, you will need 4 pinion bearings so that you can make two set up bearings for the inner and outer pinion, that you can just slip shims in and out without having to re-press them, and the final permanent set, for when you have the correct depth shim selected.
Before any gear pattern check, make sure you have the correct backlash, while carrier preload isn't necessary for the set up part make sure everything has no play.
adding and removing backlash is tedious and you have to play with the carrier shims and it gets frustrating after a while.
Hope that gives you an idea, and most of the time the drive side is always silent if it had a semi decent/perfect pattern, the coast side tends to whine if not properly centered, so take extra time for that if you decided to tackle it.
Lastly if you have a g80 is probably about time to replace that pos, even though ironically I installed a new one in my GM10 bolt. Speak of hypocrites.
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