Here's what you need to know:
- Heat KILLS transmissions.
- AW4 is one of the strongest transmissions available. No real reason to upgrade beyond the AW4 unless you are swapping for a v8 WITH a supercharger.
- The most affordable upgrade to protect your transmission is to add a supplemental transmission cooler.
- Stock XJs usually come with a smaller tranny cooler but are insufficient after lifting, locking, and armor plating your XJ.
- Buy the largest transmission cooler you can fit.
- 15" x 7-1/2" x 3/4"
- B&M model #70268 - 11" x 7-1/4" x 3/4"
Excellent Reads:
http://www.naxja.org/forum/showthread.php?t=1055170
http://jeepin.com/features/trannycooler
Transmission Temp Gauge Installs:
http://jeepin.com/features/tranny_temp_gauge
http://www.cherokeetalk.com/forum/f8/b-m-80212-trans-temp-guage-install-w-rant-included-14400/