Hey guys, the last few times i went offroading my transmission overheating light has been coming on, this is after being in 4wd for about a hour or two, i was thinking about getting a transmission cooler or oil cooler, any knowledge on what to get to help this or fix it,
PS i have 37" nitto's stock axles and driveline

thx

 

R u in 4 hi or low when this happened?

 

it only happens in 4hi

 

That's your problem then. You could add a cooler to the trans, but you say stock driveline with 37's? Transmission is working harder pushing the 37's with stock gears.

 

Well there you have it. You're probably overgeared. What is your gear ratio at the axle? Should probably be at least 4.88 with 37s.

 

I would do this 4lo, O/D off. This allows the transmission to get to 3rd, where the torque converter will lock. When I do this, I can actually see the transmission temp come down. An unlocked torque converter is a huge heat generator.

 

And yes a cooler will help too

 

I was having temp issues with mine. Installed the ORW kit and the temp came down from 200F to avg. 155F in the same situation. I monitor both the trans and engine temps with my Bully Dog tuner.

However, think about the gear ratio since you do not want to strain your transmission and mask the issue with the cooler. I installed my cooler just as a precaution for the hot days and some steeper inclines.

 

thanks guys, yea looks like ill need a regear and add a cooler to, and maybe even a diesel lol

 

Yes, a cooler will help.

Although exported jeeps 07-10 came standard with a trans cooler, U.S. versions did not have a large cooler, nor was one offered, at the time. Only aftermarket coolers were available.

In 2011, they started offering, for sale, the factory cooler for us 07-10 Jeeps.

After installing mine, the trans temps went down and I was able to use 4W-High. Prior to that, I never used high, only low gear.

There are several vendors, on this site, that offer trans cooler kits for your Jeep. They're much cheaper (cost), then the factory setup.

Click on the link below:

Off Road Warehouse Racing Parts ORW JK Automatic Transmission Cooler ORW JK Automatic Transmission Cooler Kit

Another option would be the one from PSC. If you plan on later installing a hydro assist, then this works for that.
It has a Power Steering cooler on one side and room for a trans cooler on the other:

PSC Motorsports Jeep JK Cooler & Mount Bracket Kit - PSC-MBC110K - 07-14 Jeep JK - Jeep 72-14 - Vehicle Specific Products