Question about replacing gears
Question about replacing gears I believe my stock 10 bolt gears are about to crap out on me. It started with a small whine that i noticed about 2 weeks ago, and ever since then it seems to be getting louder. Its loudest when coming to a stop from about 40 mph all the way to 0. When accelerating i can hear it start from about 15 all the way up to 45, then it fades just a bit but is definetely still there all the way through 70 and up. My main question is, that i have noticed some people have used the G.M. motive gears to replace stock. And I have been debating to go with 3.42's or 3.73's. But if i was to go with the G.M. Motive gears would i be able to use the stock shims? And it be a "simple" change just to pull the clips, and take the ring and pinion off and replace them with the Motives, reinstall and be ok. Because as long as I have the stock shims i should be ok. Also, where can i find these G.M. Motive gears? If anyone can link some 3.42's or 3.73's that would fit my application, as i know nothing about the 3 series,2 series or standard rotation. And what is the stock spline count on the pinion? A stock 10 bolt is 7.5" correct? I just want to be able to rely on my car as an everyday driver, and be able to take it on trips when needed without worry of my rear crapping out on me. And as long as i can just replace those parts with stock shims i will just do it myself. Thanks in advance, any input would be helpful.
Last edited by Fast98Z; Apr 24, 2008 at 10:17 PM.
Joined: Jul 2006
Posts: 381
Likes: 15
From: Oshawa (Home of the 5th-gen)
What gears do you currently have? 3.42's? (assuming your car is a 6-speed) or are you an auto, w/3.23's?
Anyway, unfortunately changing gears, even for the exact same factory replacement, will require setting up every time. The shim behind the pinion bearing will quite likely work with the new gears, but usually you still have to setup the back-lash a little bit, which requires different combinations of carrier shims. If you've never done it before, it's not impossible for a "DIY" job, but do your homework first!
Board member "Kaliente" has a really good write-up on installing gears ... do a search.
"Assuming" you have M6/3.42's, then you already have a 3-series gear carrier, so if decided to change to 3.73's (not a bad idea) then you'd order them for a 3-series carrier. Even if you have A4/3.23's, they're on a 3-series carrier as well. Only 2.73's & 3.08's came w/a 2-series carrier.
And yes, it's referred to as the 7.5" 10-bolt (although technically they upsized to 7-5/8" at some point in time).
Anyway, unfortunately changing gears, even for the exact same factory replacement, will require setting up every time. The shim behind the pinion bearing will quite likely work with the new gears, but usually you still have to setup the back-lash a little bit, which requires different combinations of carrier shims. If you've never done it before, it's not impossible for a "DIY" job, but do your homework first!
Board member "Kaliente" has a really good write-up on installing gears ... do a search."Assuming" you have M6/3.42's, then you already have a 3-series gear carrier, so if decided to change to 3.73's (not a bad idea) then you'd order them for a 3-series carrier. Even if you have A4/3.23's, they're on a 3-series carrier as well. Only 2.73's & 3.08's came w/a 2-series carrier.
And yes, it's referred to as the 7.5" 10-bolt (although technically they upsized to 7-5/8" at some point in time
). Thats what i had figured, thanks for the info. I think im just gonna have the GM dealer do it this time. I was able to do it with the 85, but olmost dont want to deal with it this time. I have the A4 with 3.23's, think im gonna go up to the 3.42's. , thanks again.
