I've read some stuff on the internet (must be true, right) about having a transmission running too cool and not being able to burn off excess internal moisture. Some say its almost as bad as running it too hot. When I installed my TruCool Max and SD cooler lines, this wasn't an issue I considered.

My trans runs around 130 degrees on a "not hot" day, when I'm straight driving. Get a little more heat and humidity out there, plus some stop/go traffic, I can reach 150. On a hot day, with a loaded trailer, I'm hard-pressed to see 170-180. In fact, I don't think its been over 180 at any point after the mods.

Should I be concerned about this, or perhaps trying to find a way to ramp up the operating temps a little bit?

 

I wouldn't worry about it.

 

I'm with Phil, I wouldn't worry about it. I have a 32 row 6.0 cooler and even on a hot day I'll only see 170°-180° pulling what you see.

 

3X for not worrying about it. I think your trans should be as happy as a lark with those temps. Now if you weren't getting above 120* regularly, then maybe it would be a cause for concern, but with those temps, I think you're going to be just fine.

 

Heat is the biggest enemy of any Automatic Transmission. If its staying cool then I say your fine.

Mine it doesn't seem to matter, weather I'm pulling a trailer or unloaded, I'm hard pressed to break 170 on the hottest day. I think 175 was the highest I've seen.

 

Thanks all. I tend not to worry about it, but a sanity check is always nice. Agreed that heat is the biggest enemy to a tranny, which is why I installed the cooler and SD lines. Pulling my travel trailer in the middle of the summer saw the temps climbing to 230 or so, which was alarming, so thus came the cooler. Last October, we pulled it to the north GA mountains and never even reached 150 on the trip there.

 

That sure seems like a very well functioning cooler system. I believe you are doing something correct on those temps.

 

I didnt know that the SD lines were larger in diameter.
Hottest I got mine was when I was waiting in line to get into burning man 3 hours of just idling damn near, wasnt pulling a trailer but truck was packed down. I seen 205* that night, avg is 150*

 

When I got my trans from John Woods he didn't seem to think the bigger SD lines mattered that much. He just said the fittings on the trans were the smaller size, why bother?

 

IIRC, the SD lines are overall 1/16" larger diameter than the stock lines. Doesn't seem like that alone would make a significant difference. I installed them at the same time I did the cooler, cooler line bypass fitting and trans fluid change. The biggest difference has got to be from the cooler itself, but at the time I was going all-in for a cooler running trans.

 

Was it any big deal to change the fitting on the trans to accept the bigger lines?

 

Not really, because it involved the cooler bypass valve install as well. IIRC, the bypass valve threads into the smaller holes on the E4OD, and the outlet holes are the size of the SD lines. The hardest problem was installing the new lines, because they don't have the exact same bends as the old ones, and my aftermarket exhaust was in the way.




(Photos courtesy of Cary @ CT Performance)

 

with my Large 6.0 tranny cooler ,i rarely see 170 pulling hard,thats ac blasting ,pulling the 30' camper, bed loaded with firewood and a golfcart on top of the wood.If I could just get my EGT's down now.Need up pipes I guess.
35k miles on fresh tranny rebuild with the larger cooler,no probs yet running lower temps.