4L80e Overheating

Kratos707 · September 3, 2017

Want to give another update on the transmission. I haven't had a chance to replace the lines yet but the transmission is running cooler. Today it was 110F out and the trans temp was about 190 to 200F. I haven't had any issue with overheating since the last update. I think the problem was a blockage at the transmission inlet which must have pushed through. I still plan on changing the lines since they are the original lines.

davester · September 3, 2017

That sounds about right for Trans temp. Glad you found the problem.

2008silver · April 27, 2019

I have a problem with my 4l80e it seems like it is getting stuck in first gear but if I let go of the gas pedal and press on it again then it shifts to 2nd or if I leave the gas pedal it would shift but intill 5k rpms

davester · April 27, 2019

7 hours ago, 2008silver said:

I have a problem with my 4l80e it seems like it is getting stuck in first gear but if I let go of the gas pedal and press on it again then it shifts to 2nd or if I leave the gas pedal it would shift but intill 5k rpms

Are you sure you have a 4l80e? I didn't think the '08s still got them.

Edited April 27, 2019 by davester

txab · April 27, 2019

21 minutes ago, davester said:

Are you sure you have a 4l80e? I didn't think the '08s still got them.

He has his own dedicated thread here:

https://www.gm-trucks.com/forums/topic/223231-4l80e-getting-stuck-in-first-gear/?tab=comments#comment-2245968

2008silver · April 27, 2019

Yes Im sure ..it originally came with a 4l60e but I swap it for a 80e

Tooltime86 · July 26, 2021

On 8/21/2017 at 3:38 PM, Kratos707 said:

I was wondering if anyone has had this problem with there 4L80e transmissions. On my truck the transmission overheats when driving with no load on rather mild days (75 degrees F). My truck is a 2006 2500hd 6.0l 4x4 and I have an extra trans cooler in addition to the factory auxiliary cooler. Initially I was thinking that my coolers were plugged because the line coming from the transmission was hot and the line returning from the coolers was the same as ambient temp. Thinking that the coolers were plugged I tried flushing them, forward and reverse, I even removed them, and I still get that condition of one cooling line being hot and the other being cold. I started to think that maybe the cooling lines have a blockage so i flushed them as well (both forward and reverse) but still the same problem ( i also verified that the radiator did not have a blockage since the heat in the line is past the radiator). Since this did not work I took the truck in to have the transmission flushed just in case there was something going on the the transmission. The shop checkout the pan, filter and fluid and said it looked good (no metal shavings, minimal debris, not burnt). This shop used the HotFlush system to flush the system. Even after the flush the same problem.

The system is acting like the transmission is not letting the oil back into the transmission from the oil cooler return line. Does anyone here know what could be causing this? Outside of this issue the transmission is stock and is running fine.

please help

thanks

Hey dealing with same issue. Also replaced the aux cooler and even bypassed radiator cooler. Drives good for about 50 miles and starts to over heats. Cleaned radiator and condenser out, full command on both fans makes no difference. Tried to flash tcm with tcc enabled or standard operation. Did you or anyone else find a fix for this? 2011 silverado 4.8 crew cab RWD, swapped with 4l80e. Stock lines and fittings with larger aux cooler and bypassed radiator cooler. Does shift around 3500 to 4k

Reggie Encalade · February 17, 2022

I have the same problem so if I change my transmission cooler to a bigger one it will stop my transmission from running hot transmission shifts fine runs great no problem just high temperature