ls1charged

iTrader: (8)

So im about to add a TA rear girdle... did a lot of searching and found mixed opinions... if i use Mobil1 Synthetic Gear Lubricant LS 75W-90 Part No. 104361/98W573
is the additive necessary?
If so can i use K & W Chemical Trans-X® Posi Trac® Limited Slip Gear Oil Additive, 7 oz. Part No. 402508

Or do i need the GM additive?
Thanks for any info!

RPM WS6

iTrader: (3)

You didn't specify what year the rear/car is. For 1998 and earlier (Auburn), you'll definitely want the GM LSD additive and conventional 80w90 lube. If it's a '99+ Torsen rear, it wouldn't hurt to use the additive but it's not really required (though some people claim the rear is a bit quieter with it), and synthetic 75w90 lube is fine.

joecar

The bottle of Mobil 1 says LS on it... it already has limited slip additive in it.

dailydriver

Sometimes, for a clutch pack type of diff (i.e; Eaton Posi, whether steel or carbon clutches), there is not enough additive in the various gear lube products to keep the clutches quiet on low speed, high angle turns, like pulling into a parking spot.

IF racing, and not caring about this noise, there is probably enough added to most gear oils which claim to have it in the formula to keep the clutches from wearing too quickly.

Anyway, less additive will let the clutch pack lock up quicker, and more fully for better corner exit while autocrossing/road racing.

ls1charged

iTrader: (8)

Sorry forgot that detail... its a 99....
I ended up getting the Mobil 1 and additive and added the TA cover.. install went smooth and everything feels great thus far...

quick additional question, is the Torsen a stronger/better unit then the 98 Auburn?

Thank you for your replies!

RPM WS6

iTrader: (3)

Not in my experience. The Torsens seem to fail just as often, maybe more, and they aren't any stronger; they should last longer in theory, but that doesn't seem to be the case in practice.

The Auburn is quieter, and a bit more "predictable/seamless" (for lack of a better term) in my opinion.

I've had three Torsens, two of them since brand new, and all of them chattered during low speed coasting situations in certain types of curves or on uneven ground. Never had that issue with the Auburn.