mattwj

Good evening all!

This is my first post so excuse me if this question has already been asked. I have used the search bar but can't seem to find an answer.

So I'm looking to change the front and rear diff oil, and the oil in the transfer box.

I have recently acquired a 1999 Grand Cherokee 4.7 V8 4x4 Quadra drive with a reasonably full service history, but I can't seem to find any documentation to state weather the diff oil and transfer box oil has been changed.

Can someone please tell me what oil is required for the fron diff, rear diff and transfer box?

I have been googleing this for hours, only to find conflicting information and arguments about using Mopar branded oil instead of Mobil 424 for the transfer box!

If more information is required to get an answer, I'll try to answer to the best of my knowledge.

The job of changing the oil seems to be a whole lot easier then the job of selecting the oil itself!

Thanks in advanced!

dave1123

Welcome to CF!

The information I have says the Quadra-Drive system consists of the NP247 full time transfer case with Vari-lock LSD axles. The proper lubricant for the Vari-lock axles is 75W-140 Synthetic API GL-5 lubricant with a friction modifier added. The NP247 t/case is required to have Mopar Transfer Case Lubricant in it. It is proprietary and only can be purchased from a dealer.

Sorry, but this is why I drive a 4.0 with the NP242 in it!

rgr4475

The WJ bible. Has everything you ever need to know about your WJ.

http://wjjeeps.com/

mattwj

Thanks for the reply Dave! Looks like I finally have a straight answer!

So the front and rear diff takes 75w-140 Synthetic API GL-5 and the transfer case takes the Mopar TC fluid. I'll order some now!

Thanks for your help guys

dave1123

Hang on to your wallet! That Mopar stuff is a bit pricey! I'm using Valvoline 75W-140 Syn in both my open diffs and that has some friction modifier in it, but not enough for the locker. You'll have to buy a tube to add to each.

For THE definitive manual for your jeep, check out pacificcoastmanuals.com. Their FSM is 93mb of pdf files covering EVERYTHING on your jeep. The download takes awhile, but that's where I got the info I just gave you about the lubricants. It's a reprint of the Factory Service Manual that dealer techs use.

wjjeeps.com is great, but it doesn't cover 1/2 the stuff the Full Service Manual does.

rgr4475

Be sure to buy the Mopar brand LSD additive that goes in both the front and rear even if the aftermarket fluid claims friction modifier. WJJeeps has the amounts that go in. Can't remember right now.

dave1123

OH! The FSM had the quantities but I forgot to add that. Sorry.