Hey guys, keep in mind that a 30 WT motor
oil has about the same viscosity as a 90 WT gear
oil (give or take, I don't have a chart in front of me). Motor
oil does not use the same scale a gear oil, it uses a lower one.
I've been using Redline MTL in my Tremec for 5 years with no problems. Tremec recommends Syncromesh by GM.
Bob