Saw our highest tranny temps ever while towing this week

[cowboywildbill]

Hi everone, we made a trip to Ohio on Tuesday. A lot of long hard pulls thru Md. West Virginia, Pa. and Ohio thru the mountains while towing. In the past I have never seen our trans temps go much over 200 degrees f. But this year it was hotter than normal outside, in the 90s f. usually it is about 70 degrees f for this time of year and trip. We make this trip at the same time every year. While pulling some of the grades our trans temps reached 225 or more and our engine temp about 225 or more. The fan would come on and it would cool down the engine quickly but trans took longer to cool down. It seemed like the trans temp would climb while the fan would bring the engine temp down. ?? We drove thru a storm and a cold front and the outside temps dropped to about 70. Then the engine and trans temps were way down as in the past. I wonder what will happen on a 100 degree day doing the same thing. Any one else pulled thru the mountains on one of those hot days? If so did it stay cool enough to keep running without any problems? What kind of temps did you see on trans? Is that about as hot as they get? We are bone stock including tires. Thanks.

[mark45678]

sounds like your towing really heavy or pulling a high trailer into a strong head wind ? Mike L at Inglewood trans in Cali has a over sized trans cooler that fits your truck , It will help . What are you pulling? any power adders ? what size tires are you running ? will it stay in 6th gear or do you pull in 5th in manual mode with tow haul on ? what speeds are you trying to run at ?

At trans temps over 230 the fluid looses some of its lube ability and you really should keep it under 220 if poss.


you can contact Mike with this link ....
http://dieselplace.com/forum/member.php?u=773

[cowboywildbill]

We are bone stock on everything including tires. On the way home the ambient temps were high 60s. We didn't see any higher than 200 then. We are towing a 40' LQ horse trailer about 14,000 lbs and some change. The outside temp really puts the up the trans temps more than I would have thought it would. I just have never seen it that high before. We were pulling some long 6% grades flat out. We were down in 4th and 5th on most of them. The temps would come down to around 200 when we were thru with the bad hills. I was just surprised to see it get that high. We only have 7,000 on this truck
Are the bigger coolers plug and play? or do you have to cut or adapt the lines?
Thanks

[ramblinrodney]

Mike L. trans coolers are plug and play. It's suppose to drop temps down 20 deg.

[Mark Rinker]

Personally, I wouldn't be alarmed enough to spend money on a cooler.

After these trips, drain the 7-8 quarts that comes out of the drain plug, spin on a new filter, and relax. The Allisons can take it.

If you encounter that hot day, it will make it. Adjust your speed expectations.

[cowboywildbill]

Thanks. I do have a deep pan, but I have used the deep pan on our last three trucks. And I know it helps to have the extra 4 quarts, but I never saw a temp reduction in the trucks with or without the pan. I think once the fluid is heated up 4 qts aren't going to stay any cooler under extreme pulls, but I think it doesn't hurt either. I have always run transynd in the past, I might change over to it when I service it. I asume that the New Dex IV fluid that comes in these models, will take more abuse at higher temps before breaking down than the old Dex III I wonder if transynd is better than Dex VI Thanks for the input.