Hi i am wanting to change the fluids in my front rear and tranny.

I was thinking about puting some kind of synthetic fluid in my trans.

I am wondering what fluids do i need to buy

 

If its a 4.0L with automatic, you need Dexron III/Mercon in the transmission. The differentials take 75w-90 (?) gear oil. Its in the owner's manual.

 

I had a guy tell me to put royal purple in my motor/trans/t case.

Then for my differintials to put some normal gear oil.

 

You could put Royal Purple in everything. Thats what I think you should do if you really care about the Jeep. Or mix it up. Put Royal Purple in the motor, Transmission(Royal Purple ATF, Royal Purple Syncromesh if Cherokee is 2000 or 2001 model year, Royal Purple 75w-90 Gear Oil or Royal Purple 10w-40 Motor oil if 1999 year or older Cherokee), and the TransferCase, which I would put Royal Purple ATF. Or Syncromesh. It even says on the Syncromesh specs that its good for TransferCases that require ATF. Then put Amsoil Severe Gear 75w-90 in the Front Diff and Amsoil Severe Gear 75w-140 in the Rear Diff. That would be premium.