Topic: Differential Removal??
in Forum: C3 Driveline Components
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Apache Junction, AZ - USA
Joined: 10/15/2006
Posts: 285
Vette(s): 1982,150K,Renegade CFI,Hooker Side Pipes,85 fuel pump,Bilsteins,HD suspension, Aluminum radiator, SharkBar/w 5-Point Restraints. 3:73 gears coming soon.
MERRY CHRISTMAS C3VR!!!
I am removing my stock differential and replacing with a new rebuilt unit with 3.73 gears -yeah, I know I must be crazy... but if I don't like it I will have it re-geared.
Anyway, anything I need to know about removal/installation, what bushings I should replace etc.? I will fill it with the GM specified fluid with a bottle of the GM conditioner. I am also replacing all 6 U-joints while I'm there. I do have the Service and AIM manuals along with several other books to help.
I am planning this at the same time I remove the old duel exhaust for the new Hooker side pipes.
Any advice as always -always greatly appreciated!
Thanks!
I am removing my stock differential and replacing with a new rebuilt unit with 3.73 gears -yeah, I know I must be crazy... but if I don't like it I will have it re-geared.
Anyway, anything I need to know about removal/installation, what bushings I should replace etc.? I will fill it with the GM specified fluid with a bottle of the GM conditioner. I am also replacing all 6 U-joints while I'm there. I do have the Service and AIM manuals along with several other books to help.
I am planning this at the same time I remove the old duel exhaust for the new Hooker side pipes.
Any advice as always -always greatly appreciated!
Thanks!
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Mounds View, MN - USA
Joined: 5/24/2007
Posts: 1031
Vette(s): 70 LT1 coupe, 69 350 HP coupe, 69 390HP 427 coupe, 71 LS5 convert, 85 coupe, 93 coupe
There is a bushing set by the pinion. It is about $20.00 for a new one and just bolts in. The process is pretty obvious once you start.
Larry
Larry

HOWELL, NJ - USA
Joined: 5/18/2004
Posts: 6812
Vette(s): 1979, Targa Blue (72 Color), Pace Car rear spoiler, L88 hood, Dark blue factory interior, 525HP 406, HD 700R4, 370 gears,Steeroids, composite rear spring, TT IIs wrapped in T/A Radials.
Quick Tip
- If you drop the rear cross member that the top of the pumpin is bolted into, you can lower it down and out as one unit with a floor jack since you'll have the half shafts, spring and struts out of the way already.
LukesVette 2008-12-20 07:17:34

Many folks have cut a hole in the rear compartment floor over the 4 cross member to diff mounting bolts to access them. This alleviates the need and you can spruce up the rear cross member while you're at it.
Soak the 2 crossmember to chassis bolts with penetrating fluid before you start.

Good luck. 

Paul
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'80-'82 diffs aren't bolted in like '79 and earlier diffs.
There is one mount at the front on the diff. like '79 and previous, and a mount at each end of the "batwing" that bolt to the left and right frame rails. Way easier to remove these late units vs. the older ones. Plus they are aluminum which is lighter than the previous cast iron diffs.
With the use of a lift I can R&R my diff in 4hrs. Have a friend help you lower the unit out of the car cause it is still a little "weighty" an ackward due to the span of the "batwing."
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HOWELL, NJ - USA
Joined: 5/18/2004
Posts: 6812
Vette(s): 1979, Targa Blue (72 Color), Pace Car rear spoiler, L88 hood, Dark blue factory interior, 525HP 406, HD 700R4, 370 gears,Steeroids, composite rear spring, TT IIs wrapped in T/A Radials.
Good point Sarge - didn't even realize they had a different set up. Apologies for the confusion 

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101st Airborne(AirAssault!)
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Apache Junction, AZ - USA
Joined: 10/15/2006
Posts: 285
Vette(s): 1982,150K,Renegade CFI,Hooker Side Pipes,85 fuel pump,Bilsteins,HD suspension, Aluminum radiator, SharkBar/w 5-Point Restraints. 3:73 gears coming soon.
Thanks guys!
I'll take pics as I go for anyone needing them in the future.

I'll take pics as I go for anyone needing them in the future.

I'll be watching this as I plan to do some rearend work this winter also. Got a new composite spring and the diff leaks and makes noise when turning from a stop so I might just drop the whole thing too. Picked up a lightly used mid height lift so things should be easier.
I've dropped the diff. in my '72 a couple of times and for me it was better to drop the "batwing" with the diff. I used a floor jack which worked really well and of course a good set of jackstands. Using a mid-lift would work even better, I imagine. Pics always help, I took a few while I was working on mine.
Good luck.
Good luck.
I did mine a few years ago, the wife help me steady it while I jacked it into place with a floor jack. I would recommend getting the shock mount removal tool. I just got a bigger hammer!! That cost me an extra 60 bucks I didn't count on!!
Good luck!!
Mel
Mel
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Cramerton, NC - USA
Joined: 8/22/2006
Posts: 1094
Vette(s): black 1982 coupe slate gray interior, 350 crossfire, 1985 fuel pump, Steeroids R&P conversion
Phill, Id be interested in seeing the pictures. I have some rear end work that needs to be done as well and have been reluctant to tackle the differential removal.
in Forum: C3 Driveline Components
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