Bjorn20

I have a 00 z28 equipped with a t56, bought it at ~69xxx miles, currently has 74xxx miles on it. I have no idea when the previous owner changed it, and it has been growling from the rear since I bought it. Not sure if that growling is from the rear differential, a wheel bearing, or what as I've just ignored it.

Anyway, I was looking into changing the rear differential fluid, but with that growling noise that is possibly coming from the differential, I am scared of the ATF theory of not changing fluid in a long time and the fluid is the only thing holding it together. I don't know if that same principle applies to differentials, but I'm worried that if I take the cover off, huge chunks of metal will come with it.

I've also read on here that some people don't even recommend changing the fluid if its a non race application.

What to do?

LS6427

iTrader: (2)

Drain a little out and see what it looks like. It would suck if you were just low, and you let it go and it fails soon.
Replace the axle bearings too, they're cheap.

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1 FMF

iTrader: (1)

the growling in the rear may be normal if you have a auburn differential which has clutches, the gear fluid is worn out and needs a drain and refill. If you have the auburn, it's recommend to use a mineral gear oil with the typical 4 ounces of friction modifier added. Not sure if you can tell via the vin what differential you have, but in any case simply draining the fluid and refilling with fresh gear oil and limited slip additive will not make it die any sooner, if anything not changing the oil will help it die sooner especially if there's a lot of wear particles floating around.

kdoublep

iTrader: (1)

Open that baby up! I did at 75K. I have Auburn (1998 TA). I always have a little whine as stated in previous post. You have nothing to lose by checking. Fluid is not holding that thing together. I use lucas with no additive necessary and it's fine.

Mine is a DD with 104K. I bought her brand new in 1998.

Bjorn20

Is there anyway to tell if you have the Auburn setup besides checking the VIN? I would imagine mine is just equipped with a normal standard issue gearing, but you never know. Looks like I'll be calling the dealer.


I must be new to rwd applications, because I have never heard of an axle bearing? Is that part of the rear wheel bearing?

I just wish there was a drain plug directly underneath the pumpkin to make for a quick 30 second drain and fill.