I posted this in super duty forum, still learning how to navigate this site, sorry mods.

Ive searched the forum, cant seem to figure out the problem....

SO out of nowhere, my tranny started over heating. Got up to 210. It usually runs in the 140-150 range. I have the 6.0 cooler, and 7500 miles on the synthetic fluid. My cooler lines to the radiator were ice cold. I crimped my bypass and this seemed to fix it a little ( i know this is a no no), I did the flow test before driving it and it passed. It seems to heat up the most at stop lights in gear. It drives fine, no slipping, no chattering. I also dropped the pan, had some stuff on the magnet, replaced the filter too. It doesnt seem to heat up as bad now, goes to about 190. I will install the new bypass tomorrow when it comes in from the ford dealer. Any guesses on whats causing the heat?

BTW truck has a 4" lift with 35's no other mods

 

Poor air circulation.

 

210°F isn't overheating, but I understand your concern. It's running hotter than before and the cooler lines are not hot. That's a fluid flow issue.

Since crimping the bypass didn't fix the problem, the new bypass isn't going to fix it, either. You do need to replace the crimped bypass, but that isn't what's wrong. I believe your temps went up and the lines are cold because the cooler or cooler lines are plugged. You need to find the restriction and remove it.

 

thanks mark, so if i pull my cooler out can i just hook air up to it and blow it out. I just replaced the bypass before this post. Did the flow test and got a quart in 15 seconds. no fluid coming from the bypass. I have read many posts, just not sure how to tell if its the cooler, or the line. Thanks again.

 

If you got a quart in 15 seconds through the cooler and all the lines then it isn't plugged. That's a good flow rate for a 4R100 transmission.

See if it still gets hot and if the lines stay cool.

 

Well drove it 40 miles with the new bypass in. Stayed at 180, currently sitting in the cab with my foot on the brake in gear and temps are climbing, been about 15 mins so far and it's at 195.

 

That's normal. They all do that.

 

well im going to blame it on global warming, pulled a light trailer and it didnt get over 170