Need some help trying to diagnose an overheating issue. I have a 2017 f150 with the 2.7 and 6r80. I replaced the factory cooler lines with -8 lines straight to x2 Derale 15800's and back to the trans (no radiator). Truck has 37" tires (load E) and 5.13 gears. I had it out at KOH and didn't have any issues. Memorial weekend I drove out to Parker from Indio and had to pull over at Chiriaco Summit, Desert Center, and Rice to let the trans cool down because it had reached 253* It has gotten hot on a couple other local drives on the freeway and around town. When I got back, I dropped the pan and filter and replaced the fluid (always Mercon LV). Kept driving, kept getting hot. I put a thermostat bypass valve in to keep constant flow to the coolers and no difference. Called a transmission shop and he's stumped as well. I checked fluid levels hot and cold, and also checked for cavitation. Coolers are mounted to a bed cage (see photos). I am not getting any hard shifts or anything like that. I am at a loss and tomorrow I have to drive to Apache Junction, AZ. Any Ideas??
6r80 Transmission getting hot
- Thread starter PREHNTR
- Start date
badlinesgoodtimes
Administrator
- Joined
- Mar 30, 2022
- Messages
- 938
clogged cooler ? Assuming fans working properly on the coolers under load and its not some electrical issue with the fans cutting out?
Klever
Well-known member
- Joined
- Apr 7, 2022
- Messages
- 355
If you can put the coolers up front...you probabaly won't even need fans. Where are you measuring the temperature from?
Fans work. Theres should be enough rows to not have to use the fans but even when they are on, it isn't really changing anything. When I'm stationary, they will drop the temp, but underpower temps go back up.
Truck has it on the dash. I have no room to put them up front. From factory it has a tiny one mounted onto the radiator. That got hot too when I was on 35's
Klever
Well-known member
- Joined
- Apr 7, 2022
- Messages
- 355
Gotcha.
Where are you measuring the temperature from? Disreagrd...LOL you have a guage on the dash...which the temp sender is in the valvbody. Try driving with tow/haul on. See if that helps.
If it has a shit ton of miles; it may be worn out and slipping, causing excess heat.
If that's pan temp or return from the cooler...that's a bit warm. But if that's coming from the converter (out) that's a totally normal temp.
Wish I could be more help, but I am not so hip on all the new technology etc. I do old school transmissions like TH400 and 4L80 ha ha!
Where are you measuring the temperature from? Disreagrd...LOL you have a guage on the dash...which the temp sender is in the valvbody. Try driving with tow/haul on. See if that helps.
If it has a shit ton of miles; it may be worn out and slipping, causing excess heat.
If that's pan temp or return from the cooler...that's a bit warm. But if that's coming from the converter (out) that's a totally normal temp.
Wish I could be more help, but I am not so hip on all the new technology etc. I do old school transmissions like TH400 and 4L80 ha ha!
Last edited:
Truck has it in the setting on the cluster.
Attachments
Ill give the tow/haul a try. Yeah new trucks are a pain in the ass. 72.5k miles, no codes. Thanks for your input
84Prerunner
Well-known member
That’s not enough cooler being mounted there. Hook the factory heat exchanger back up and all your problems will go away.
It was getting hot then too.
In bottom out the top then in the bottom out the top. I bought the adapter plate from PBH and it is -8 so I ran it all -8
84Prerunner
Well-known member
-6 vs -8 has basically no effect in this situation.
It was over heating in bone stock configuration?
It was over heating in bone stock configuration?
Little update. Started my trip with the tow/haul and fans on. Noticed the temps were stable so I turned it all off. Made the whole trip with no issues. Sometimes you just gotta smack it and yell at it and it starts working. Ran like a dream the whole trip. Thank you for the input
Similar threads
