Getting ready to change the diff oil to Redline Syn. 75w90 - how much does it take? Redline already had LSD additive in it, but have heard good things about the GM LSD additive. Any input? Thanks!

 

I used the Redline at my last diff oil swap... good stuff. You need two 1-quart bottles.... I used one whole bottle and about 1/8th of a second bottle to top off the diff.


Cheers,

PeteH

 

I use Royal Purple 75w90, it takes about 1 1/2 qts.

 

As others have said, you'll need to buy 2 quarts, but you'll only use about 1/2 of the second bottle (or less)
No need to add more additives, unless you have an aftermarket clutch-type differential. then additives can be used to 'tune' it.
Mika

 

How often should you change the LSD fliid?

 

I change mine at 30k, but after I drained it, it still looks clean to me. So I think it can last a lot longer.. maybe 50k?

 

I'd do it every 30K. I just replaced my fluid for the second time at 30K (1st time at 5K to remove break-in debris) and it was already murky looking. I used Redline 75W90 both times.
Mika