Kymasabe

I need to change my rear diff fluid, and I don't know what rear is in my WJ. I'm thinking maybe a Dana 30....but not sure. So, would anyone happen to know what rear diff usually went in a 2004 WJ, 2WD, with a 4.0 liter ??
OR, is there a link online where I can enter my vin and get the build sheet that'll tell me? I've found some links that'll tell me rear gear ratio, but not which diff.

Next, am a big fan of Amsoil Sever Gear rear diff fluid, not going to change brands so please don' pitch your favorite brand. I just need to know what weight I should be pouring in. Is my wifes WJ, sees daily commuter duty and occasionally will tow a 3000 lb boat and trailer, and only a short distance, maybe 30 miles round trip. I was thinking 75w140 but am wondering if too thick for so little towing.

4.3L XJ

That would be a Dana 35. If you want to be sure take a magnet and try to stick it to the center. If it sticks, it is a D35

00t444e

Probably a Dana 35, 75w140 synthetic is fine, I run 85w140 in my axles.

Kymasabe

Thank you guys, I'll double check in the morning, but I think you're right, probably a Dana 35. At least I hope it is, I ordered my LubeLocker rear diff gasket tonight.
And, I was considering a 75w90 synthetic, but I think I'll just go with the 75w140 Severe Gear instead, it worked in my F150, Dakota's, and my XJ Cherokee, no reason I can't dump it in my Dana 35.