I put in a 195 degreet T-Stat from NAPA. Since the tranny is running with the heavy duty OEM cooler and still shifting nice at 246K, I'm not going to change it now.

 

It was 55 degrees this morning. I kicked the fan on using my dash switch. Driving to school at 35-45 MPH for 15 miles in traffic, my digital readout never went above 177.8 degrees F until I got to school and had to play musical stop signs...then it hit 181.

 

What is normal operating temps for these trannys?

 

my numbers are water temp off the computer buss. Transmission wise, since the trans lines use the radiator as a fluid-to-fluid-to-air intercooler, whatever the hotter fluid is, the cooler fluid will be close to.

 

On my SLT, there are transmission lines going into the radiator as well as there is a separate trans cooler sitting below the AC condenser and in front of the radiator. So it's being cooled on both levels, unless I'm mistaken?

 

that's the towing/heavy duty package. Which side is the auxiliary cooler tapped from, the top or bottom fitting? I'd have to look, but I think mine was top inlet and bottom outlet.

 

I'd have to look and let you know. One thing I researched to death, was the new radiator. The 1.25" single cores at your local auto parts store (and all over the web), does not cut it. Not when you're replacing a dual core 1.5" thick OEM. You will run on the verge and probably will overheat if towing or very hot weather. The 1.63" single core I got, cools pretty well. I may be tempted to do the 180 deg t-stat.

Kinda regret the napa "premium" stat that I put in now. Shoulda gone OEM for reliability. Maybe next summer...

 

I run a napa gold. Considered the best of the market.

 

Old thread, I know, but I am needing to replace my 2 year old cheap 1.25" aftermarket radiator and this thread has intrigued me.

Is your 1.63" radiator still cooling well? I wish I could find a stock max cooling radiator for a good price. I have found some used but don't know if I can drop $100 on a used radiator.

 

Yes, it's cooling just fine. Needle stays below halfway mark.