gear change
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Have you never changed gears? Might be better to have it done if this is your first attempt and it's your Vette.
I've heard it can be done for as low as $250 depending on where you are.
Thread Starter
Burning Brakes
Joined: Feb 2006
Posts: 841
Likes: 0
From: High Desert California
I've never even tried to open one. Maybe a member from So. CA. can chime in if they happen to know a shop that's reasonable. Thanks Durango for the heads-up. Knowing myself, I probably will take it apart and won't be able to put it back the right way 
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Instructor
Joined: Dec 2006
Posts: 131
Likes: 0
From: Flushing Mich
What is the deal with the diffs...seems all the part numbers stop at 1979
Also can't seem to find stuff on the net regarding the iron to alum diffs
Help!
Melting Slicks
Joined: Oct 1999
Posts: 2,581
Likes: 14
From: Tolar Texas
I did a gear swap/rebuild on my '80. It wasn't unreasonably difficult but I sort of lucked out and things fell in place for me. I carefully measured and noted the thickness of all shims and where they came from. My new ring gear was basically the same thickness as the old one so everything worked out right on the first try. If I would have had to disassemble it to adjust the shims a few times, it would have been more difficult.
At the time, knowing that norvalwilhelm had offered to back me up with technical assistance gave me confidence to dig in and do the job myself.
GTR1999 has probably offered more advise on this topic than anyone. Here's links to a couple of Gary's posts related to differential rebuild:
Differential paper
http://forums.corvetteforum.com/show...ighlight=paper
Differential Rebuild Pic's for use w Paper
http://forums.corvetteforum.com/show....php?t=1236684
Here's a link the thread I posted back when I did the job.
I have completed setup of the 3.73:1 gears in my DANA 44
http://forums.corvetteforum.com/show...highlight=dana
At the time, knowing that norvalwilhelm had offered to back me up with technical assistance gave me confidence to dig in and do the job myself.
GTR1999 has probably offered more advise on this topic than anyone. Here's links to a couple of Gary's posts related to differential rebuild:
Differential paper
http://forums.corvetteforum.com/show...ighlight=paper
Differential Rebuild Pic's for use w Paper
http://forums.corvetteforum.com/show....php?t=1236684
Here's a link the thread I posted back when I did the job.
I have completed setup of the 3.73:1 gears in my DANA 44
http://forums.corvetteforum.com/show...highlight=dana
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
Let me toss out another option. Just get a complete differential with the gear you want and swap the whole thing. Bag your original, and stick it in the corner or sell it. Takes you out of having to setup a new one and makes it an afternoon deal. There are several places that have complete posi's all ready to go. May be more $$ but it is an option.
Thread Starter
Burning Brakes
Joined: Feb 2006
Posts: 841
Likes: 0
From: High Desert California
That was "sweet" Mike. Both your's and Gary's were outstanding. But since my car is a 1981, I'll be using your thread more. It sure gave me hope, I thought for a while I was stumped and had to take the car to a shop. 
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Instructor
Joined: Dec 2006
Posts: 131
Likes: 0
From: Flushing Mich
I did a gear swap/rebuild on my '80. It wasn't unreasonably difficult but I sort of lucked out and things fell in place for me. I carefully measured and noted the thickness of all shims and where they came from. My new ring gear was basically the same thickness as the old one so everything worked out right on the first try. If I would have had to disassemble it to adjust the shims a few times, it would have been more difficult.
At the time, knowing that norvalwilhelm had offered to back me up with technical assistance gave me confidence to dig in and do the job myself.
GTR1999 has probably offered more advise on this topic than anyone. Here's links to a couple of Gary's posts related to differential rebuild:
Differential paper
http://forums.corvetteforum.com/show...ighlight=paper
Differential Rebuild Pic's for use w Paper
http://forums.corvetteforum.com/show....php?t=1236684
Here's a link the thread I posted back when I did the job.
I have completed setup of the 3.73:1 gears in my DANA 44
http://forums.corvetteforum.com/show...highlight=dana
At the time, knowing that norvalwilhelm had offered to back me up with technical assistance gave me confidence to dig in and do the job myself.
GTR1999 has probably offered more advise on this topic than anyone. Here's links to a couple of Gary's posts related to differential rebuild:
Differential paper
http://forums.corvetteforum.com/show...ighlight=paper
Differential Rebuild Pic's for use w Paper
http://forums.corvetteforum.com/show....php?t=1236684
Here's a link the thread I posted back when I did the job.
I have completed setup of the 3.73:1 gears in my DANA 44
http://forums.corvetteforum.com/show...highlight=dana
Is the diff in the 81 a Dana 44?
Thread Starter
Burning Brakes
Joined: Feb 2006
Posts: 841
Likes: 0
From: High Desert California
Let me toss out another option. Just get a complete differential with the gear you want and swap the whole thing. Bag your original, and stick it in the corner or sell it. Takes you out of having to setup a new one and makes it an afternoon deal. There are several places that have complete posi's all ready to go. May be more $$ but it is an option.
Thread Starter
Burning Brakes
Joined: Feb 2006
Posts: 841
Likes: 0
From: High Desert California
Le Mans Master
Joined: Jul 2004
Posts: 6,248
Likes: 4
From: Lancaster PA
Let me toss out another option. Just get a complete differential with the gear you want and swap the whole thing. Bag your original, and stick it in the corner or sell it. Takes you out of having to setup a new one and makes it an afternoon deal. There are several places that have complete posi's all ready to go. May be more $$ but it is an option.
Instructor
Joined: Jan 2007
Posts: 167
Likes: 0
From: Provo Utah
Yes it uses a Dana 44 and imho, if you havnt done it before i would pay to get it done. I've priced it out and my total has come to about $640 including tax. $160 for yukon 3.54 gears, $130 for master kit, and about $350 for labor. Thats for new gears and a professional install. If something happens, it's under warranty. The install price will of course vary, but those are the cheapest i have found for R&P and master kit. let me know if anyone has any cheaper
Thread Starter
Burning Brakes
Joined: Feb 2006
Posts: 841
Likes: 0
From: High Desert California
I have a friend who has a shop but he's about close to 100 miles away from me and his only day-off is Sunday. Can this be done in 1 day if we take it out for him and have him change the gears and put the diff back?
Melting Slicks
Joined: Oct 1999
Posts: 2,581
Likes: 14
From: Tolar Texas
IF he has the proper tools, and some experience with this type of work, it is possible. You would need to remove the rear end while at your house, remove the rear batwing cover, drain the oil and be ready to pull out of your driveway by 5-6 AM.
Prior to your arrival at 7-8 AM, your friend should have all tools located, laid out and ready to go when you arrive with the rear end and all replacement parts.
As long as you don’t run into anything unusual I think you could possibly return home by 10 PM with a freshly rebuilt rear end ready for installation.
However, it is VERY possible you will find that your side yokes and cross shaft which holds the spider gears may be worn thus needing replacement. Consider pre-purchasing new/upgraded versions of these items before you plan the day trip.
Side note: . . . Before installing the yoke and pinion seals, put a thin film of sealant in the bores. I didn’t and my seals weep. Not nearly enough to drip but enough to moisten the outside of the case.
Prior to your arrival at 7-8 AM, your friend should have all tools located, laid out and ready to go when you arrive with the rear end and all replacement parts.
As long as you don’t run into anything unusual I think you could possibly return home by 10 PM with a freshly rebuilt rear end ready for installation.
However, it is VERY possible you will find that your side yokes and cross shaft which holds the spider gears may be worn thus needing replacement. Consider pre-purchasing new/upgraded versions of these items before you plan the day trip.
Side note: . . . Before installing the yoke and pinion seals, put a thin film of sealant in the bores. I didn’t and my seals weep. Not nearly enough to drip but enough to moisten the outside of the case.
Last edited by MIKER; Feb 6, 2007 at 09:13 PM.
Thread Starter
Burning Brakes
Joined: Feb 2006
Posts: 841
Likes: 0
From: High Desert California
Yes it uses a Dana 44 and imho, if you havnt done it before i would pay to get it done. I've priced it out and my total has come to about $640 including tax. $160 for yukon 3.54 gears, $130 for master kit, and about $350 for labor. Thats for new gears and a professional install. If something happens, it's under warranty. The install price will of course vary, but those are the cheapest i have found for R&P and master kit. let me know if anyone has any cheaper
