View Full Version : Rear Gear Oil

02-21-2006, 08:13 PM
I need to find out what gear oil to use for my new 9" rear. I'm planning on using 2.5 pints of GL-5 80/90w gear oil. If this is not the best stuff to use, please let me know. Any recommended brands? Also, should I use the Positrax additive, if so what does it really do? Thanks a lot.

02-27-2006, 08:58 PM
Does it ever get to freezing temperatures or will you ever drive it during those temperatures ?? If not, I like using a straight weight 140..... from Schaffer, Torco, LE or Amsoil.

If it is a friction type clutch pack, use a friction modifier (positrax). The old Ford friction modifier is still the best I have ever used, but they dont make it any more. Redline also has an excellent fric mod that you can get from a performance dealer.