How many of you running an automatic transmission have had your transmission fail long before it should have? Automatic transmissions that are subjected to high torque situations at slow speeds build an extreme amount of heat. The 1998 TJ Wrangler, that I am currently running, spends a lot of its life on the sand dunes at Silver Lake Michigan. What an awesome place to spend a weekend but the low tire pressures in loose sand at slow speeds causes a tremendous amount of heat build up in the transmission. The transmission cooler that is built into the radiator is great for normal driving conditions but does not provide adequate cooling of your transmission fluid if the vehicle is used in extreme conditions.
The transmission in my TJ Wrangler was recently rebuilt. The overhauler installed high performance clutch discs, because of my style of driving, and at the time highly suggested an external transmission cooler. We installed an Allstar Performance cooler that easily attached directly in front of the radiator. This cooler was rated for an 18,000 lb. GVW rating with core dimensions of 12″ x 7.5″. It is important that during the installation of the unit that you do not run the external cooler in series with the current radiator cooler. This can actually cause the transmission to run at a higher temperature due to the engine coolant heating the transmission oil to the same temperatures. Again it is important to completely by-pass the transmission cooler when using an external cooler.
We have had several trips to the sand dunes and local off-road parks and the transmission fluid is still bright red. I feel confident that my transmission overheating problems have been corrected.
Baseline 4x4 Outfitters 