Yuk! 36K diff oil

[Chris142]

I drained and refilled the diffs,transmission and transfercase in my 02 TJ Jeep today.

Yuk the diffs were nasty, black with shiny metal looking stuf in em and thin as water!

The transfercase fluid was black too but no metal. The front diff is always turning although not driving the Jeep unless I am in 4x4.

Anybody know what oil Jeep uses when they fill em at the factory? IMHO it didn't hold up well in a street Jeep. I put Torco 75w-90 in the axles, Pennz synchromesh in the trans and Valvoline ATF+3 in the X-fercase.

 

[Grossomotto]

Most likely the cheapest dino GL-5 gear fluid. 30K+ for dino gear lube can do just that. If you submerge your axles or do a lot of towing, it can be shot even earlier!

I change all my drive axles at 30K with RedLine gear oils. It's about the same price online as dino gears oils in the store. I've seen great results with RP, RL, M1, Amsoil, Castrol, etc.

First and foremost, change it at least every 30K and you should be fine with any factory spec gear oil.