just changed diff fluid. i went w/ amsoil 90/140. when it gets warm or after being in use for a few miles. i will stop, then proceed to take off and there is a grinding 'feel', not noise, just feel. any additive i should use? went with the higher 90/140, instead of the 75-? so, anyone when have any suggestions? thanks.

 

I use amsoil all the time with no problems. If you use one of their severe gear products 75/90, 110, 140 it has the friction modifier in it. Our axles DO NOT need it but some have reported the same symptoms as you and added the additive and it fixed it.

 

I'm using the 75w140, has been doing a GREAT job. I have 15K on what's in the diffs now, oil sample says it is still like new oil. I was planning to change it out at 20K of use life, but I think I will go a bit longer because the sample suggests I can. I think the 'grab' you are talking about is normal for these AAM's, they do feel different than the old dana axles but seem to perform just fine.

CD

 

it has never done this before. it was clean when i changed the fluid, no shavings, etc. what type or brand of friction modifier should i use?

 

Look carefully at lube requirments for the AAM axle. It is different and does not require a additive. 140 is not better for it.

 

i used the 75/140............hmmm, not liken' it. any suggestions? add something or drain and do again?

 

Your lower weight should of been 75. Your higher 90 weight is why it is acting funny. It is too thick.

 

YES it is to heavy.