Trans cooler addition 6l80

[Kervin]

Alright so I’m curious for some input here. I’ve got an 09 Tahoe 4wd LTZ with no external trans cooler in front of the radiator. Only the internal cooler in the radiator. My trucks lifted and some bigger rims and tires and I do tow every once in awhile. Drove up the east coast from SC to CT a couple months ago for the military and noticed my trans temps got into the 220s going up really steep grades going 80+ With it being 90 degrees out. Coolant temp rose from my normal 198 to 215 as well. Not fun. I want to add a trans cooler for when I do tow or go on trips like that. Normal driving I’m under 195 usually between 170-190. I’ve heard conflicting things. Told that the temp has to be in the 170-190 band for the 6l80s like this at all times so a trucool 40k might be too much. Also saw on a couple forums that the 40k blocks too much air from the radiator so when towing up grades the coolant temp gets high. Wondering if plumbing in a 20k would be more than enough or if I can get the 40k. Forgot to add in the future I’d like to put a deep trans pan on the truck from B&M.

 

[Foggy]

I'd keep it simple... Just put on the bigger pan. It's a great time to service your trans too.
The bigger pan will hold 2-3 more qts of trans fluid and help cool things.
Your temps right now are very normal/average and you are not harming anything at
those temps... If you are not towing in the mountains regularly , I'd keep it simple !!!

 

[swathdiver]

If yours were mine, I'd install the factory external cooler and lines. Have the system on my trucks and I don't tow through Death Valley or the Eisenhower Tunnel.

Higher temps shortens fluid life. So if you see higher temps like that, it ain't hurting anything in the short term but if you fail to run the severe service schedule, transmission life will be considerably shortened.

Slowing down will allow the cooling system to work as designed too!

 

[intheburbs]

Since you should be changing your fluid more-frequently with these transmissions, I say send it as-is. Dex VI is pretty good stuff. The "trans hot, idle engine" warning comes on around 262°. These transmissions were designed to have an operating temperature of 190-200°.

 

[donjetman]

your temps are normal

 

[diesel_dave]

I agree with the other comments. Those temperatures are nothing to be concerned about and I wouldn't really do anything at all, but if you want to do something, just install the factory trans cooler option. I see trans and engine temps of ~220-230 degrees with my 6.2 for nearly an hour at a time while towing heavy up grades in the desert heat. Not concerning to me at all. Just make sure you change the trans fluid more frequently if you routinely operate at these temps.