'96 XJ here and I'm changing out my rear diff and transfer case gear oils for the first time and have a couple questions.

Looks like both the diff and transfer case use about 3 qts of oil each and I have two different kinds (3 qts each)...



The Master Pro is from O'Reiley's

Are these two oils ok to use? Since the XJ has an open differential I just got the cheap stuff that doesn't say 'for use with limited slip differentials.' $5/qt. vs. about $11.50/qt. Which brand should I put in the transfer case and which in the diff? Or should I take these two back and use something different altogether?

 

STOP! The transfer case takes atf.

 

Pick up a cheap Haynes or Chiltons manual, that will save you the hassle of waiting for us to look it up for you.

 

You need to find a manual and read. The TC takes ATF not gear oil. You'll only need about two quarts for each differential with the rear taking more than the Dana 30 front. Find out what kind of rear diff you have before deciding on the oil.

 

www.kelleyswip.com/tech.html, follow the links. Specs pulled from FSM, corrected where they're known to be wrong (there are only a couple.)

Generally speaking:
Engine - 10W-30 winter, 10W-40 summer
Transmission:
- AW4 takes Dexron II/IIE/III/VI (four-speed automatic) Avoid the use of +3/+4, as it is known to cause clutch slippage and chatter.
- AX-15 takes GL-3 80W-90. (Most shifting problems can be corrected using 10W-40 engine oil instead. Do not use GL-5, unless it specifically states it's "Safe for use with Yellow Metal"!) (five-speed manual)
Transfer Case - All take Dexron II/IIE/III/VI.
Axle, Front - 80W-90 GL-5 gear lubricant (regular or synthetic)
Axle, Rear - 80W-90 GL-5 (regular service) or 75W-140 GL-5 (heavy service, towing, hauling.) Check for the presence of an OEM clutch-based limited slip differential (should be a tag under one of the cover screws, the clutch packs are also slightly visible under the side gears) to use "Limited Slip Differential Friction Modifier." Nota Bene - If you're not sure the first time, you can go ahead and add it. The presence of FM will not damage gears, nor will it cause any trouble if it's not necessary.

Those specs are from memory, which can fail me at times. So, check my site. Capacities should also be listed.

(The Dana 30 rear axle can be differentiated visually from the ChryCo 8.25" - the ChryCo housing has a rather flat bottom, looking vaguely hexagonal resting on one side. The D30 is more ovoid. The primary difference between the two is fluid capacity, for your purposes.)