Just within the last several months when towing at slow speeds (25MPH and under) uphill my trans temps rise significantly. I mean like 40 to 50 degrees higher than the past. Just came back from a hunt where trans temp hit max on the gauge 280. Rolling down the highway trans temp reads like the past. Any suggestions on what i could be facing?

As always appreciate the input

Chris

 

I assume you checked the cooling fan operation. The thermostat in the line going to the trans cooler from the tranny could be closed and not opening.

Pull your dip stick and see if the tranny fluid smells burnt. If so change it.

The 315's you have on have changed your rear ratio the wrong direction for towing unless you compensated for the tire height by changing the rear ratio, say from 3:73's to 4:10's.

My tranny while towing and running without the fiver on the highway, runs about 100 degress above the outside temp. If the sun is on the front of the truck it will drive the tranny temp up some.

Don't know what your towing or how much it weighs.

Dave

 

Where is this thermostat located you are talking about? The fluid is not burnt at all. I've pulled a couple different trailers both bumper pulls. 1 6k other 10 to 12k same trans temp problem. I was talking to one of the menchanics that works on our fleet at where i work and he said if the trans did truly get that hot 280 trans fluid would be burnt. Maybe my gauge or the sending unit is the issue.

 

Facing the cooler its in a small block in the upper right hand corner. There's a post on here showing a print. I've had issue with the little bugger several times.
The next time it gets funky I'm pulling it and turning it around so it shuts off the cooler bypass. I can tell when it's malfunctioning because I can feel the throttle valve in the transmission sticking when restarting with a warm engine. I have an 03, it still has a TV cable so I can feel the transmission throttle valve pulsing in the pedal.