I haul a 1200 lb (approx) truck camper. Up slow steep grades my trans gets to 240 degs quickly before I stop to let it cool. I read elsewhere that I need to put it in 4low to prevent this. Is that it? Wanted your input before I go spent a few hundred on a deeper trans pan, if that would even help. It has ATF+4 in it. And I have also read the fluid can handle much hotter, but what is the safe max temp before I should pull over. Is 240 too late? Thanks.

 

How slow you going up the hill? What gear?

240 is pretty dang warm for a little 1200lb load, especially with 265 tires and a 4.10 rear end...

 

I agree. It did happen to me once pulling out of a campground but I seldom top 200* even on steep grades towing about 11K. Do you try to keep your TC locked up or are you going too slow for that? Are you sure your gauge is reading right? You can verify with a non-contact thermometer pointed at the pan to get a good idea. If it's right, I'd look for a trans. cooler problem, like a stuck check valve. I don't know if 4 low would help.

 

I'm having the same problem that EPCO is having but pulling a bumper pull 5k and 12k in weight. Fan clutch is working. On the highway trans temp is fine even pulling grades. Slow going on dirt roads pulling grades is where the trans temp climbs. I have not tried to put in 4lo but i was also told the same thing. I think the 4lo thing is a bandaid. I wonder if the trans cooler thermostat is having a problem. There is something wrong. Prior to the issue first happening no issues with trans temp going slow on grades. Anybody have any suggestions for us. Did not mean to streal your thread EPCO.

 

No problem. Typoed the weight. Camper is closer to 2000 lbs, if that makes a difference. But this is happening on slow moving 10-15 mph grades with washboards and many switchbacks etc. I am assuming the guage works as I get 160-180 normal driving temps through the mtns. Measuring with Genos Acutemp adaptor.

 

Looks like we have to clean the thermostat. I am not going to reverse it like they do in the thread, but it looks like the cleaning will help a lot.

http://www.cumminsforum.com/forum/3r...nning-hot.html

 

Way too hot, make sure you use tow/haul mode, I tow a 36 foot 5th wheel and the most I see is around 205, I forgot t/h mode one time and she got hot pretty quick, mine averages around 180 towing flat and hills.

 

I have an 01 with the auto, 3.54 gears and I shift it into 2nd.
Brings up the rpms and helps my truck allot towing my camper at slow speeds.

 

Thats very good advice. If a lot of people would do this it would make it much easier on the truck!

47

 

The trans in my '03 would get really hot towing my old 10k lb toy hauler on dirt roads in 1st and 2nd gear. Highway speeds were fine, it'd summit a 7% grade like a bat out of you-know-where without any trouble. Reading on here, it has to do with the torque converter slipping in 1st-2nd.

By the way, if your ATF is brown/smells burnt do a complete change by removing the lower line on the transmission and purging it (15 qts.).

 

The torque converter won't lock at low speeds, that's the problem. Pulling a heavy load up a grade at very low speeds (below 40 mph) will heat things up...but not sure why it's happening with only a 2,000 lb. load.

I can get the torque converter to lockup at around 40 mph in 2nd gear on my '07 by manually shifting into 2nd, but at lower speeds it won't lock. I don't know how the transmission responds for other model years.

 

Shift it to 2nd. You should lockup when going slower. Your truck may not have the overdrive lockout, just the tow haul. I can't remember the name of the company, but they make a box that will allow both the tow/haul and overdrive lockout for the 05' trucks. The 06' and above will do this stock.

Dodge did offer a reflash to disable Tow/haul and make it OD lockout. If you use a Smarty this will get deprogrammed back to Tow/Haul.

 

EPCO i saw that thread about the trans thermostat. I talked to the old boy at the shop up the road and he said he has never seen an issue with the thermostats. I'm going to R&R it maybe this weekend. Nothing to loose. I'll keep you posted

 

I have heard of the thermostat in the tranny cooler sticking. There is a good how too on Competitiondiesel.

 

Try towing with higher engine RPMs. The pump speed on the tranny is directly related to the engine RPMs. More RPMs moves more fluid helping to keep it circulating and cooling.