ok so a couple friends of mine where telling me that LSD oil is the same as tranny fluid so when i filled my tranny this weekend with red line senthetic i swapped the LSD's oil as well so now to the problem. now when i take turns sometimes from a stop say makeing a left or right turn from a stop light or stop sighn i feel this grinding in my seat comeing from the rear axle one of my friends said they even heard a grinding sound. it didnt do that before does anyone know what this might be? o BTW its an 87 S4 T2

 

What oil did you swap in there. Your diff needs something that has a friction modifier like the Redline 75w90.


I use MT-90 for the trans.

 

I used 75W 90 not good? o.o;;

 

Did it say LSD oil or LSD compatible on the bottle?

 

Redline 75w90 should be good. Did you fill the diff until it started to leak out of the fill hole? If it still makes noise then you might have to get an addional friction modifier to add to your diff. I've seen a little bottle of friction modifier at Napa before. Its a small white bottle with a red label saying limited slip differential supplement on it.



75w90ns is the one you don't want to use if you have a lsd.

 

how often should one change LSD oil...same time as tranny?

 

>.< it is 75 W90NS eh so i guess i go to andvanced and get some 75 W90 x.x i hope my diff's not fry'd

 

Your lsd is ******* fine. add a friction modifier. And tranny oil and diff oil are the same thing. Some formulations are for one or the other, but they are both gear oil. It's all preference.