Anyone know what this stuff is ? The dealer told me it was whale oil.?.? I have found that it is absolutely necessary in a GM 10 bolt with an Auburn LSD.
Car is a 94 pontiac formula LT1 at 60k miles the rear end started making a terrible noise like a rusty bolt being worked during slow speed turns,driveway maneuvers etc. Changed the fluid with M1 75w90 and gm lsd add and it was fine for another 150k miles. At 200k miles I just changed the fluid with M1 75w90 and left out the add. Rear end made the same awful noise at low speed turns when the clutch plates were working. added the lsd add and noise went away. BTW the posi still works perfectly at 203k miles. Still leaves two nice 75 foot black stripes. It appears the M1 lasts at least 3x as long as the factory fill.
Car is a 94 pontiac formula LT1 at 60k miles the rear end started making a terrible noise like a rusty bolt being worked during slow speed turns,driveway maneuvers etc. Changed the fluid with M1 75w90 and gm lsd add and it was fine for another 150k miles. At 200k miles I just changed the fluid with M1 75w90 and left out the add. Rear end made the same awful noise at low speed turns when the clutch plates were working. added the lsd add and noise went away. BTW the posi still works perfectly at 203k miles. Still leaves two nice 75 foot black stripes. It appears the M1 lasts at least 3x as long as the factory fill.