Trans upgrades... recomendations

Okay, here's the deal. I currently wheel an 87 XJ with a manual trans. I bought my wife a 99 XJ about 2 years ago. The deal is when we are financially able to buy her a new ride (hopefully a Grand), I am going to sell the 87 and start building, driving, and wheeling the 99. That said, my questions revolve around the auto. First off, which model is it. Also the t-case is a 2wd, 4pt, 4ft, N, 4lo, what is the model of the case? Now the real questions, which mods and in which order should I install on the tranny. I know that the main cause of failure in the auto is heat so a cooler is pretty obvious, but is the rail mounted cooler sufficient or should I go with a finned, oil cooler style. Also, are there any extra cappacity pans with drain plugs and temp sensor taps available? What about synthetic fluids, extra resevoirs, etc. The most exteme wheeling I'll prolly be doing is something like Tellico, there aren't that many rocks here in FL and I have my 63 CJ-5 for playin in the mud so the XJ will see about 75% use back and forth to work and the rest on the FL trails in the forest and such. Mainly just trying to protect this trans so it's worth something when I get it. Thanks a bunch for any help you can provide. I couldn't find a generic trans thread but if you know of one please let me know where. Thanks again, Chris.

You have the AW4 and 242 in that '99. Regular fluid changes and you're golden. It is a strong unit.

"What about synthetic fluids"

Dextron III Mercron. this is all you should use in your AW4. NOTHING ELSE! the AW4 is a very strong box

Thanks for the input guys! Would you recomend against a cooler and larger capacity pan?

cnflxj said:

Thanks for the input guys! Would you recomend against a cooler and larger capacity pan?

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Cooler is good. Pan may be unneccessary.

The only larger capacity pan I've seen was home made, but coolers are inexpensive and easy to install. I bought the largest one I could fit in my grill and ran it in-line with the stock one.
These AW4's are super stong, they're the same tran's used in supras with 500 hp.