1966 Rear Differential Help

[Barry J.]

The gentlemen restoring my car called and mentioned that the rear end had a slight grinding sound while turning the rear wheels. The rear end is not locked up . The car is a 1966 425 with only 30K miles on it has been parked since 1971.

He mentioned I may need a new rear end!

Any ideas or suggestions?

[Michael G.]

Re: 1966 Rear Differential Help

Barry,

Others more knowledgeable I'm sure will chim but with the information you've supplied haven't given us much to go on. Is your guy versed in the diagnosis of a Corvette differential? If so, he should be able offer more detailed information other than "slight grinding sound while turning the rear wheels" before I'd feel comfortable replacing the rear diff.

[Russ S.]

Re: 1966 Rear Differential Help

Add a bottle of limited slip additive and see if it gets better.

[Gary R.]

Re: 1966 Rear Differential Help

Sounds like posi chatter, typically heard starting and turning a corner. Sitting for years doesn't help if it was exposed to moisture you may need bearings. I would do the oil and additive change first and see.
Even if it needs a rebuild do not exchange it, rebuild what you have. The 66's useda 1st design Eaton, those are prone to cracking but that would lock it up which you say you don't have.
IF the car is being restored I would expect the diff to be at least opened up and checked. Maybe they didn't get to that but I would ask the plans for it.
If I can help just let me know. I have a lot of pictures of what your 66 diff looks like inside.