[notsure]

I want to change my gears from 3.08 to 3.55 ring & pinion can I just change gears or do I need to change shims all so. rear end from 77 corvette.

[Crosley]

you most likely willl need to re-shim the side carrier bearings for the proper ring gear lash .

the pinion gear shim may remain the same .

you need to check the depth of the pinion gear to the ring gear for the pinion shim thickness

[barnym17]

I hate to say this but if you have to ask, have it done.The reason is many special tools such as a case spreader, pinion depth gauge, dial indicators etc are needed to do it right.Many people have changed just the gears and been ok , many more have done it and destroyed an expensive rearend.It shouldn't cost to much to have it done, far less than the tools cost.

[notsure]

Thats why I asked to see what was all involved in changing ring & pinion out I am having a hard time finding someone where i live Avon Park,fl to do the work.

[barnym17]

Sometimes it is tough to find some one because the tools cost so much.A lot of times you can get by but not always. the hardest part is the case spreader Gm used a device that opened up the case slightly to aid in installing the shims they slip in with the spreader installed and when it is removed the case provides preload on the shims.

[The Factory Man]

Have you checked with the Chevrolet dealer to see if they could do the work on your Corvette differential?

[HalfOunce]

I would bet that would be extremely high at the dealer. Most shops in this area charge around 400-450 labor to go through a differential.

[The Factory Man]

You won't know until you ask what it will cost! Having the right tools and experiance is worth something. I would not recommend that the average guy try to work on a differential at home because of the special tools, selection of shims, knowledge and experience that is required. I have set up hundreds of differentials but always had the tools and shims that were required. I'm not saying it can't be done at home but be sure you know what you are getting into.

[cranky1]

I own a spreader but have only used it once! The trick I've found is once you get the proper setting on the backlash using just enough shims to let it slip in and out easily, I warm up the races and add the right amount of shims to give the correct preload and slip it in. Been doing it that way for years and it doesn't take much heat to make the races expand enough and it works a lot faster and easier than using that heavy arse spreader. I also have 'trial' bearings that slip on and off easily to help make setup easier. Once you get the pinion set, remove the trial bearings, stick on new bearings. The trial bearings are also new and unused to keep the settings as close as possible once the permanent ones are on there. It never varies more than .002"

[302 Z28]

I spent my early years working in the local Chevy and Ford dealerships and never saw a case spreader used. They always shimmed until they go the correct pattern and pre-load and wedged it in slightly tapping with a wooden mallet.

Why the change from 3:08 to 3:55 that is not going to produce much change.?

Vince

[cranky1]

Originally Posted by 302 Z28

They always shimmed until they go the correct pattern and pre-load and wedged it in slightly tapping with a wooden mallet. Vince

I've done it that way too...until I messed up some shims and didn't have anymore to finish the job lol.

[notsure]

I want to change to the 3.55 for better take off and still be able to do highway driving without the high rpms.A t least that what I am told 3.73 will be a bit too much.