Just picked up my 4th F-body, a 95 Formula M6. After a burnout or two I noticed the rear would whine when going around a corner at slow speed. As of now it only happens when you turn, there's no noise when cruising or anything. It does still leave two black stripes when you step on it, no 1 wheel peel, so the diff is still good, but I wonder if it's on it's way out. I haven't checked the fluid in the rear either, any tips on doing that? Just pull the drain plug and peer in there?

 

I recommend changing the oil and putting friction modifier in. When I picked up my 98 someone had installed 3.73 gears but had very obviously forgotten the friction modifier, as it always moaned when I would pull into a parking space. Most parts stores carry the stuff, should be right by the gear oil and it will say on the bottle that it can be substituted for the gm part # that gm stocks as their friction modifier.

If it still makes noise a while after that then you'll probably have to pull the cover off and do an inspection. IMO it's one of the worst parts of the car to work on. BTW if you've never changed gear oil before consult an instruction manual. On f-bodies there's only a fill plug, so you'll need a siphon pump or you'll have to pop the cover off.

 

I did some searching and found a few posts on how to check and change the diff fluid. I'll probably just pull the cover so I can look at everything inside anyway, it can't hurt and I don't have a pump so might as well. Here's hoping it's just low on fluid and I don't have a shredded posi unit, or worse

 

Well, I went and picked up 2 qts of synthetic 75w90 and some LSD additive. Popped the cover off, and a small splash of fluid came out, less than 1 qt probably. No metal fragments or shavings that I could see, and no shredded fibers from the posi.

Refilled it, put on a new gasket, some RTV, bolted it back up, took it for a test drive. No more whine or howling! I'm a very happy F-body owner.

Thought I should give an update. Brent Franker's website was quite helpful with it's "4th gen lube how to". http://www.bfranker.badz28.com.

 

Not to get off topic, but when are you goning to change that disgusting avatar?

 

LOL. Just for you km9v. This one should be considerably less disgusting, I hope.

 

Thank you & may God Bless!