Rear Differential lube ??

[Dave Remillard]

I recently changed the gear lube in the rear differential with Amsoil lube. Amsoils claim is that no friction modifier is needed (wrong). When refilling the diff. with lube, I installed the recommended amount and did not allow for modifier. I have already added one 4. 5oz. container of Napa brand modifier and need to add at least one more, this time I will use the Mopar lube. Do I, or should I remove some of the gear lube before adding more modifier? I know over filling anything can be bad, but how much is to much. Thanks

 

[LSMITH]

I would recommend that you jack up one side of the rear as high as you can, let it down and then do the other side. Let it down. Add your modifier and then fill to the bottom of the fill hole. You can't overfill a vented diff enough to blow out seals ETC. You need to be sure that you have some oil in the axle tubes or you will have seal and bearing trouble.



All trucks are just a hair different. If the LSD in yours is tight you will need more modifier than a looser LSD. Lots of guys run the amsoil without modifier, some need it. Mopar modifier is the only one I have tried that even makes a difference, the cheap store brands do not make any difference in my truck.