smgbad

iTrader: (1)

Going to be changing my rear diff fluid on my 99 T/A. Also going to be dropping the transmission pan to change the filter and fluid (not the whole thing, just the pan drop method). How much of each fluid will I need to buy in order to fill 'er back up. And what types are recommended? I was thinking of going with Royal Purple in the rear gear, and any ol' tranny fluid... BTW... not sure which rear diff I have. I changed out the rear gear from a 3:10 to a 3:83 a couple of years ago, and changed the fluid then (although i had a friend do the fluid and I have no idea what he put into it.... some commercial fluid he had lying around his jobsite I think. The GM gearset he put in has been whining a bit ever since then, and he did put it in correctly, so I don't think it was a very good brand of gear oil). Any suggestions would be much appreciated as I eas looking ot do this this weekend or the beginning of next week.

HAZ-Matt

iTrader: (8)

What rear end do you have? Those are unusual gear ratios for the 10-bolt. The OEM rear axle ratios for an auto were either 2.73 or 3.23. Not to unfairly criticize your friend, but if you don't get the gears perfect they will whine.

At any rate, you only need 2qts of 75w90 for a stock rear end. However, unless you are using a pump you might find it difficult to get all of each bottle into the rear while it is under the car. Some people just buy extra bottles, some find other ways to get it poured in.

For the transmission, if you drop the pan you will probably only need 5 qts of ATF.

smgbad

iTrader: (1)

Its not the auburn I don't believe (if memory serves). And the gears I had installed were 3.73 in place of the stock 2.73's.

HAZ-Matt

iTrader: (8)

I really just wanted to make sure it was the stock 10bolt you had bc if you had some other rear end the oil capacity could be different.

If it is the original Zexel-Torsen (or another diff like it) then you don't need LSD additive. If it is a clutch based diff you will.