Here is my problem...
I took my truck on a 1200 mile trip this weekend to get my new trailer...
All the way there on the Interstate my trans temp was reading 125-150, but as soon as you stop, idle around a parking lot, or just moving slow it will heat up to around 250 in just a minute or less...
But if you leave it in Park idleing it doesn't move up from where it was when you stopped...
On the trip back (loaded) it ran around 150-180 moving but did the same thing when stopped or moving slow in traffic...
Any suggestions?

 

your temp sensor needs to be on the hot line (oil discharge) for an accurate reading, sounds like to me its not there if yer readin 150

also the oil is circulating in any position except part

your A/C condensor is upfront with the oil cooler and radiator so if you were runnin A/C that will reduce the exchange of the oil cooler as the air will be preheated

 

I have the Cummins hot line with the adapter fitting to work on the 96, thats where my prob is...

Wasn't running A/C, it was 27 degrees and snowing...

 

check the air side of theoil cooler and make sure it isnt plugged up with dirt/oil/crap........................the oil is circulating thru there but it isnt getting any exchange seams like

 

I drove the truck again yesterday...
It was 29 degrees out, trans temp reached 140 driving with the trailer still hitched...
After coming into town and stopped at 2 red light the temp increased to 210...
If I stop and put it in park and just let it idle it will cool all the way down to 150ish in just a couple mins...
Only gets hot idling in gear or moving slow without the converter locked up...

On my trip I had to go up a 8% incline for 4.5 miles...
It pulled in OD at 55 mph (speed limit) trans temp stayed at 180 (where it was before the hill) all the way to the top...

Just doesn't make since to me...