Transmission Temp spiking

[JD Mark]

'14 2500 Cummins with 118,000 miles and certain parts fell off so it has a Bully Dog tuner, generally run it in whatever the third position is. Actually gives me better mileage than the second position. Never had it in fourth or fifth because I figured those were breaking stuff tunes. I do a lot of plowing and limited towing. Towards the end of last winter I noticed several times the tranny temp about the same as the coolant temp while plowing, which never happened before it was always at least 20° lower than coolant.

I did have a tranny service and Thermal Bypass valve replaced in August. They said the fluid looked good.

Towing a Bobcat the other day, probably around 11K with the trailer, I noticed my tranny temp gauge climbing. A lot. Higher than the coolant and it actually touched 240° for a minute. I checked it and it still looks and smells good.

I also had 4 codes thrown:
P0733 Gear 3 Incorrect Ratio
P0732 Gear 2 Incorrect Ratio
P0868 Transmission Fluid Pressure Low
P0218 Transmission Fluid Over Temperature Condition

Any thoughts, suggestions...I am not the slightest bit comfortable going into winter with this transmission.

On another note, I know some marketing genius at FCA thinks it's kewl to have 3 different transmissions even though that has always been the weak point on Dodge trucks, but is it possible to put an Aisin in my 2500 with some aftermarket programming?

This is why 3 transmission options is stupid:

I can get a 3500/4500/5500 with a Cummins or Hemi and get the Aisin.

I CAN'T get the Aisin in a 2500 with a Cummins that puts out far more torque than the Hemi can ever hope to in stock mode.

My 2500 with a Hemi has yet a different transmission than my Cummins or a 3500/4500/5500 with a Hemi.

The Aisin is by all accounts the best transmission Dodge\Ram has ever offered. Put it in EVERY truck you sell. Less cost because you won't need different programming. Fewer parts to stock. Fewer vendors to deal with. Less training for techs.

Someone at FCA needs to get their cranial ****** inversion corrected.

 

[Fast69Mopar]

If you are having these issues now then it wont be long before a failure occurs. How long has it been since the transmission service was performed?

If you have a low line pressure DTC and a high temp DTC, the first thing I would do is get the pan off of the trans and inspect the filters to make sure they are both properly installed. I would also make sure the sump filter seal has been properly installed into the trans case.

 

[tjfdesmo]

My first thought is dislodged filter.

 

[turkeybird56]

Blocked coolant line, not circulating??? Filter blocking??? Hmmmmmm. MAYBE the Thermal Bypass Valve is defective. Would not be the first time a part was bad also. Just clutching at straws here....

 

[JD Mark]

My transmission shop guy is thinking second and third gear clutches are slipping causing the heat.

The heat has happened with 2 different valves, before and after the service. Could possibly be a blocked coolant line?

Thought I mentioned it, but I also towed my fifth wheel about 500 miles around Labor Day...after the service and replacing the Thermal Bypass Valve. So I highly doubt it's a filter or bad bypass valve.

Have it scheduled for them to drop it and take a look week after next. I can't take chances going into winter.

 

[68PowerWagon]

Getting rid of that Thermal Bypass Valve would be my first task. My transmission is running 25-35* cooler with it removed. Then flush it out & put fresh fluid & filters in it.