68RFE heat up and searches while towing, 32K miles

[tconerly]

Have 09 3500 with auto trany that runs temp at 150 degrees until stop and go traffic and temp can go up to 225 d after slowing.
Trany jumps and hunts gears after heating and sets code for 2nd gear ratio error. In extreme cases it locks up in 4th gear.
After parking for a few minutes, it returns to normal. Local Dodge tech could find nothing but changed oil and 2 filters.
Could this possibly be a sensor problem????

 

[HBarlow]

It will be difficult for anyone to offer meaningful advice without knowing anything about your truck and its duty cycle and maintenance history.

What differential gears? How is the truck used ie what does it tow and how much? How many odometer miles? How has it been serviced?

 

[Cummins12V98]

In all different towing conditions my temp has ranged from the 150's to the 180's. In 60 to over 100 degree weather. One time in Palm Springs I was on Hwy 111 for about 15 miles of stop and go with the trailer and I looked and the temp was 225-230.

From what I have read my temps are on the low side for my weight and conditions. I did a complete trans fluid swap at around 2,500 mile to AMZ/OIL Universal Synthetic Oil.

 

[EricBu12]

I put a Mag hytec pan on mine and that added 1 Qt. capacity. . with the aluminum housing and the extra capacity, I bet the temps and shifting might normalize on yours. . I have the same year truck but not a Dually. I tow a 36' 5th wheel. . One thing I do when I tow is I use the button shifter to shift up and down. . I don't usually leave it in "D". that seems to make it like a maual and you more in control