I posted this on the towing forum, but also wanted the help of fols on this forum.

Okay we just finished towing our 7100#TT with our 2005 4X4 Dodge Ram CTD with GVWR of 8300# (loaded weights at CAT scale on I-84). BTW I have 15400 miles on the CTD and had the tranny and diff fluids changed by Dodge dealer before I started towing this season at 14300 miles.

We towed from Tucson AZ to Cascade ID. Climbing towards Flagstaff on I-17 there is a long and relatively steep grade (may be 6%). The outside temps were 104F. About 3/4 of the way up the hill my tranny temp was getting uncomfortably close to the yellow range on the high side. The Banks Dynafact tranny temp guage has the high end of the green range marked at 240F. Engine temp stayed fine. So I decided to pull into a rest stop that is at the top of the hill and let the tranny cool down.

MY CTD is fully equipped for towing with a tow rating of 13000#s. So to say the least I was disappointed to experience this with my 7100# TT.

I also went on a sight seeing trip up Snow Bank mountain in Cascade ID today; no TT this time. To get to the top of the mountain you climb about 3000ft in about 15 miles. We were in 4WD Hi and in 2nd almost all the time as the road up is a national forest road. The outside temps were around eighty. Again about 3/4 of the way up I was seeing tranny temps approaching 240F again no problem with engine temp. So we pulled off in a turnout and took some pictures to let the tranny coold down.

Today I went back up the same mountain an when tranny temp guage showed around 230F, I stopped and shot the tranny casing next to the sensor probe with a non-contact thermometer. It read 187F. So now I don't know what to think.

My questions to the experts out there are:

1. Is this normal? I think not, but I am a novice when it comes to Diesels and trannys.
2. Could my tranny temp guage be calibrated wrong? If so How can I test that? What is the best location to shoot with a infra-red thermomemter to get the temp of the tranny?
3. If the tranny is really getting that hot should it be and what can I do to fix the problem?
4. Would a bigger or a second tranny cooler help?

Thanks in advance for your help

The Pakman

 

It's tough to say if your gauge is properly calibrated or not. I think it would better serve as a reference guide so to speak. The important question is .....what are your tranny temps running on a 85 deg day, unloaded, not towing, on a straight flat hi-way smokin along at 75 mph??? You need a control temperature to reference the temperature in question. The increase in temp over a normal run will tell you better what's happening in your tranny.

If you do that much towing in hilly areas tho, I'd say it would be a good idea to run a deaper than stock finned pan no matter what you find out about your temps. Pretty cheap insurance.

The old way of testing tranny temps is to pull out the dipstick and see if you can hold it between your fingers. If it just about freekin burns ya....well it's too hot.

 

pakman,

I know the hill you speak of on I-17. If you were in second, or third gear less than 45 MPH your torque converter was probably not "locked-up" and your experience is exactly like mine was on the same hill.

I changed my valve body(allows 2nd gear lock-up) and put a new TC in. I can now pull maximum weight without taxing the motor and don't see temps over 190*. This was an expensive upgrade and I was dis-appointed to have to do it but I am happy with the results.
tom

In town I do see really high temps though ~210*

 

TFeore:

How can tell if the TC is locked up? I know I know you are saying to yourself what a rookie! Hey but we all were at some time or the other!

Thanks for your help

The Pakman