Just purschased an 04.5 2500 cummins with 90K on it 4x4 sb qc. Was going to change all fluids out on it just wondering whats best for our cummins engine, transfer case, transmission, and diffs. Also if theres any other maintance I should expect to do? How do I tell if my truck has a limited slip rearend?

 

Use the motor oil of your choice i use rotella but you will get a funny smell after an oil change if you use it, alot of people use amsoil and valvoline, what transmission do you have? transfercase is ATF+4, and the diffs are 75W90 synthetic i used the valvoline synpower. hopes this helps you.

 

its the stock tranny I believe the 48re.

 

then that fluid also is atf+4

 

at 36k miles i switched to full amsoil everywhere. I am now at 75k miles and every oil analasys has come back with no problems. I think its worth having everything uniformed and able to get it from one place.