Rear differential clunk

[SenorNoob]

I've been running a LS axle as long as I've had my truck. Never even had a bottle of friction modifier. I do run 75-140 fluid though which supposedly has the same effect.

 

[lil_Blue_Ford]

I've been running a LS axle as long as I've had my truck. Never even had a bottle of friction modifier. I do run 75-140 fluid though which supposedly has the same effect.

Most of the synthetic oils have friction modifier in it already. Some people claim it’s “not enough and you should add a bottle” but the more friction modifier you add, the less the clutches grab.

 

[sgtsandman]

I've been running a LS axle as long as I've had my truck. Never even had a bottle of friction modifier. I do run 75-140 fluid though which supposedly has the same effect.

I've noticed the same thing Lil_Blue_Ford has about synthetic gear oil. A lot of times, it will say somewhere on the bottle there is additive already in there.