TJ Deep Sump Transmission Pan
By Jimmy Vance

When I purchased the '99 TJ, I opted for an automatic transmission instead of the 5 spd manual. I did this for a couple of reasons:

  • I drive the TJ everyday and getting stuck in Houston traffic with a stick isn't fun.

  • Reading many articles about rigs setup for rockcrawling and most run the automatic.

  • Talking with others who I wheel with who run an automatic.

The first trip out with the '99 was in Moab Utah. The year before I was in Moab with my '97 that had a 5 spd. All I can say is WOW, what a difference the automatic made. No more feathering the clutch when climbing. No more 3 foot shuffle trying to manage the clutch, brake and accelerator. Just ease up to the obstacle and give it a little go juice. Coming down is a bit different, some engine braking is there, but the brakes are needed at times.

While climbing a near vertical wall on Poison Spider Mesa, I did find one drawback to the automatic. As I started up the wall, the extreme angle and forward motion sloshed all the fluid to the rear of the transmission and the filter pickup was exposed to air. This wasn't a good thing as the Jeep just stopped pulling for a few seconds and I sat there motionless and had to cram on the brakes. Once the fluid covered the filter again I was able to climb the wall. I told one of the others I was with, who also ran an automatic what had happened. He just grinned and said, yeah that can happen, I run an extra pint of fluid to prevent it.

It's only happened to me that one time, but ever since I've been looking for a solution. The folks at Tri County Gear have come through with one. The kit comes complete with everything you need to upgrade to a deep sump setup. An added bonus is the pan has a drain plug!

The kit can easily be installed in a few hours. Follow along through the installation process.

  1. Support the Transmission/Transfer Case assembly and remove the factory skid plate/crossmember.
    (I tried doing the installation without removing the skid plate, you can get the old pan off but with the extension tube and new filter installed there is not enough clearance to slid the new pan in place)

  2. Remove the old pan
    This is the messy part, the factory pan does not have a drain plug so you must loosen the bolts and drop one end of the pan to let the fluid drain.

  3. Remove the old filter and clean any old gasket residue of the transmission case.

  4. Piece together the new filter, extensions tube and gasket with the supplied bolts.

  5. Position new filter assembly in place and tighten the three bolts to factory specs.

  6. Install new pan and gasket, torque bolts to factory specs.

  7. Install drain plug.

  8. Put the skid plate back in place. Torque transmission mount nuts and skid plate bolts to factory spec.

  9. Fill with new fluid.
    IMPORTANT: Only use Chrysler approved fluid ATF-3 or ATF-3 Plus. Dexron or Type F is not the proper fluid and the transmission will not work properly.

The only thing lacking in the provided Tri County instruction sheet, was how much more fluid the pan would hold. When just changing the filter the factory book says to add 3 pints (11/2 quart). I added a total of 5 quarts before I had the proper reading on the dipstick.  To properly check the fluid level, the engine must be running with the transmission in gear. The fluid should also be at normal operating tempature and not cold.

As you can see in the picture the new pan is more than twice as deep.
Before installation I applied a few coats of paint to the new pan.
After I had already finished the installation, the service writer at my local Jeep dealership has informed me deep sump pans are available from Mopar now.