I just had a complete new trans installed 3k ago. Temps on transmission sitting idle like in drive thru will go from 120-140 to over 200 by the time I leave the window. Sometimes it gets over 220 in the pan. I have taken out check ball inline, bypassed oil to water cooler so just using air to oil cooler. My engine temps go from 180 or so to 200 or just past line. Gets hotter faster if running the A/C. Just replaced fan clutch, water pump and thermostat. As soon as get back on road the TC locks early on it's own and cools everything back down. Trans temp with converter locked for several miles will go back down to 120. Trans shop says everything is tight causing heat at stand still. Fan clutch does engage I can hear fan pick up speed. Yes I have searched but can't find my problem on here maybe overlooking but any help would be great.

 

Why did you bypass the water to fluid cooler? Fluid to fluid heat exchangers are the most efficent for heat transfer.

 

I thought maybe it was putting heat into trans but wasn't case. I am thinking I need to get a aftermarket cooler w fan and hookup the water to oil cooler again.

 

Make sure you don't have an air pocket. In stop and go traffic tranny temp will climb to what you have stated. That's not a problem, it's normal.

 

Make sure your condenser/radiator are clean and clear of obstructions.

 

I've never had problems with temps like this before when temps climb 100+ degrees in a matter of minutes can't be normal. I've sprayed the radiator and condenser down several times I even made a wand to go down between radiator and coolers. I thought about taking it out and cleaning it.

 

Use an infrared thermometer on the pan, and see if it's close to what your gauge is reading. Could be a bad sensor.

 

I put one on the pan and cooler lines it's showing near same temps. Talking to dodge tech they told me to clean or replace the cooler since it's near same price to have it flushed as to buy a complete new aftermarket cooler.

 

Hmmm. Food for thought.

The auxiliary cooler has an internal thermostat that controls fluid flow through the cooler. When the transmission fluid is cold (less then operating temperature), the fluid is routed through the cooler bypass. When the transmission fluid reaches operating temperatures and above, the thermostat closes off the bypass allowing fluid flow through the cooler. The thermostat is servicable.

I wonder if the thermostat might be stuck allowing the fluid to bypass.

 

Where can I get a rebuilt one cheap??

 

I pulled the thermostat and ran it for a few days to the same effects. I am going to take off the stock air to oil cooler and run a new one along with one that has a thermostatic controlled fan.