Diff fluid question for 02 cummins
 

Hey guys about to do front ball joints on my rig :argh: fun fun lol NOT!! but anyways while the rig is down i was gonna go ahead and change out the front and rear diff fluid and some other stuff just woundering if you guys had any input on what fluid you have used or if it really dosnt matter thanks!

Front end, automatically 75w-90 (full syn). As far as the rear end, if you do a lot of trailer pulling, 75w-140 (full syn). Otherwise, 75w-90.

i like royal purple... just about everyone that hauls at our sale barn runs a mag hytech filled with royal purple... dad has 265,000 miles hooked to a 32' steel cattle trailer with no rear end problems yet... knock knock..

dodge recommends 75 140 full syn in rear with posi trac additive and front 75-90 full syn

My reference says Dodge recommends a 90 or a 110, but 140 won't hurt anything. Synthetic of course.

when i changed the diff oil in mine i called the local dodge dealer and that's what they told me to use

Does anyone know what they put in them from the Factory? as far as SYN on Not Just curious

factory is not synthetic. I have run 75w90 amsoil in my truck and it helped pick up some mileage from what was in it

thanks for all the help guys! sorry it took me so long to get back on here couldt get to laptop :( lol but thanks again:c:

OP,

Not sure if you have completed your task yet or not, but something I learned when I did mine. On the passenger side I pulled the axle out in order to get plenty of room to work with. There is a seal inside prior to the CAD. I messed the seal up putting the axle back inside and it started leaking fluid on the passenger side. It was a pain to replace that seal as well, so if your still in need to do the job, just becareful if you pull that shaft out.

oudive