Have you confirmed the temps with an infrared thermometer or something of that nature? (sorry if you've already answered this.........I read the first part of this thread the other day and am too lazy to re-read! )

 

Not yet, I got paid today, so I am going to stop and get one today on my way home.

 

Cruising 130 - 140, towing 170-180. Highest I have seen was 190-200, backing the trailer up into my driveway...

 

well that was another $70 wasted. Truck in drive with one of the kids standing on the brake (simulating sitting at a light because thats when the temps climb the fastest) gauge says 210 and the inferred thermometer says 99* to 128*. So I am still in the dark as to what is wrong. I am going to try and return the IR Therm, but I think the stick is to small for it to read off of.

 

So today I hooked up to a 8 - 9000 pound Airstream trailer and with in 12 - 15 minutes the trans temp was over 260 and almost to 270 and i had it in the tow/haul mode. Lucky for me I got to where I was going just as it hit 260, so i parked it ad it has been sitting. I am starting to wonder if the probe is bad, I am going to call Dieselmanor in the morning and see what they think.

 

Couple days ago, I was on my way from San Diego up to Oceanside (about an hour drive) and it was about 95* outside...well, on the highway, I was seeing 194* engine temps and 180+/-* tranny temps at 70mph on the highway and I have 4.10s. Now when I pulled off the highway and had the stoplights to deal with, engine temps got up to about 208* and tranny temps got up to around 210*...dropped off the trailer, got back on the highway and everything went back to normal. I think that external heat is a big factor with these trucks...these trucks also do HORRIBLY in stop and go traffic, and unfortunately, southern california is FULL of that. Guess that the only thing that can be done is to upgrade to a bigger tranny pan and that's IT. My truck is FULL of fluids, so it's not a truck issue...they just don't deal well with hot days.

 

Try 95-120F days in AZ!

EMPTY...I get off the freeway 170F...After sitting at 2 lights i can be at 210F!

I had to pick up the wife at work (car in shop) one day last week & had to fight her daily traffic crap...Every time traffic would stop, slip the trans into neutral; everytime it moved, slip into drive. Yes a pain, but on an 85F day, the trans STAYED at 165! Normal 75mph freeway run, at 85F, the trans is at ~160-170F Needless to say, I WAS SURPRISED!
But then again it makes sense. In Neutral, the trans disengages the convertor (stop heat buildup) and just pumps fluid through the coolers.

HTH

Tony