Jeep Cherokee - Transmission Installation Procedure: AW4 ['97-'01 XJ] 

Operation 242: Complete
This tutorial closely follows the Hayne’s manual for the AW4 removal procedure. It is intended for 1997-2001 applications, but the AW4 hardly changed through the years so if you factor in small things like the speedometer cable, vacuum lines and different electronics, the information presented here can also be used in 1987-1996 Cherokee XJs and Comanche MJs with the AW4.
If you’re putting a 1998-1999 transmission into a 2000-2001 XJ, here’s a few things I learned along the way:
-The dipstick tube is slightly different for 4.0’s equipped with a coil rail instead of a distributor. I used the original (2001) dipstick tube with my replacement (1999) transmission.
-The transmission mount for 1987-1999 models is slightly offset, while the 2000-2001 mounts are centered and have an additional alignment hole/peg to ensure you put it on the right way. Make sure you buy the correct mount for your year. RockAuto sent me the wrong part.
Also note: 1997 Transmissions have different electrical connectors, but with minor (maybe 20 minutes) work you can repin the connectors and make it fully functional in a 1998-2001 and vice versa.
When you replace the transmission, it’s a perfect opportunity to replace or modify various other components:
-Transmission mount: (1987-1999 models): www.rockauto.c...
-Transmission Cooler lines: (You’ll have to do some research, you might be able to find them at the dealership. If you do, please let me know, I’ll update this with a link. I opted not to replace mine because leaking engine oil had protected them from any rust through the years.)
-Driveshaft U-Joints: www.rockauto.c...
-Extend the Transmission and Transfer case vent tubes using 5/16 hose: www.rockauto.c...
-Add a transmission cooler: • Jeep Cherokee Transmis...
-Upgrade the 4wd shifter linkage: www.amazon.com...
-ZIP TIES
Here’s all the tools you need for the operation:
-Sockets and wrenches from 8mm to 19mm
-7/16 and ½ inch Deep sockets
-¾ socket for the Crank pulley
-10mm Allen bit for the Transfer Case Drain & Fill plugs
-4 Jack Stands and a Jack (Maybe 2 jacks)
-A Transmission Jack
-A whole bunch of extensions
-Large screwdriver or Panel clip pliers
-Mallet
-Various pliers
-Special: E-12 Inverted Torx socket for the upper 2 transmission bolts: www.amazon.com...
I took this opportunity to swap my NP231 Transfer Case for an NP242, if you’re considering doing the same thing I have a video documenting the process: • Jeep Cherokee - All Wh...
The Crossmember bolts are M10-1.5" x 30mm. Autozone sells them in a 3 pack.
The Transmission Mount to Crossmember nuts are torqued to 16 FT LBS.
Transmission Mount video: • Jeep Cherokee: Transmi...
The AW4’s main weakness is overheating. Most XJs did not include a factory transmission cooler and it’s highly recommended to install one. I think the reasons my transmission ran into issues are:
-It never had a transmission cooler, and there were many occasions where sitting still with no airflow could’ve potentially overheated it. Transmission fluid deteriorates very fast when overheated, and bad transmission fluid will destroy clutches. It would occasionally slip out of second and third gear and even though I replaced the filter and dumped a new few quarts of fluid into it, after not even a year it came out burnt in a brownish-gray color.
-I “raced” a few people a few times, and hard starting with a shift into second gear at 4,000 RPM will definitely wear out some clutch packs. I won against a Kia Soul, and lost to a Dodge Neon, Jeep Liberty, Subaru Outback and pretty much everything else on the road. BUT at the end of the day torque is what really matters so I win against all those vehicles offroad.
This replacement transmission was removed from a 1999 Cherokee Classic and is factory mated to an NP242. It had approximately 230,000 miles on it and its condition is “I dunno, it worked a long time ago so it might still work”. I bought it on facebook for $260, and that included the transfer case, shift gate and bezel, and an interesting story about how some drunk guy drove into a tree at 50mph, completely incinerating the front end of the Jeep.