Trans cooler for GM 4L80 4sp auto

LDB · Mar 7, 2011

My transmission was just redone under warranty at 62k miles. It had a code 8xx which means slipping. That caused the pump pressure to go to maximum. That caused the 1-2 shift to SLAM really hard. This is all based on what I was told after leaving it. I pick it up tomorrow and will get final information.

I'm wondering if heat was a factor and if I should add an aux. trans cooler. If so, who does good work at reasonable prices to add one on? Thanks.

chefdennis · Mar 7, 2011

Go to any major auto parts house and pickup a 10,000 lb trans cooler and take it to a garage that you trust. It really isn't a hard job and should cost you any more then maybe 2 hrs of flat rate labor charge...

stamp11127 · Mar 9, 2011

Just my 2 cents for what it is worth. Should you go that route I'd also recommend a transmission temp gauge and what the working temp of the fluid should be. It will still cool in winter unless the cooler is controlled with a thermostat.

scottm4211 · Mar 9, 2011

I think unless you're towing with it an aftermarket cooler isn't necessary and the problem you had was an anomaly. That's typically a very stout transmission.

goslow · Mar 9, 2011

scottm4211 said:
I think unless you're towing with it an aftermarket cooler isn't necessary and the problem you had was an anomaly. That's typically a very stout transmission.

I agree the 4L80 and 85 are very stout transmissions and can handle allot more torque than that 6.0 is putting out. If you run hard and at high speeds or tow then yes I would get a trans cooler. But if you are a professional "read safe and easy going" driver then I really to not see a need for one in expediting, unless A) you run the rockies allot B) idle allot C) do jack rabbit starts.

LDB · Mar 9, 2011

My driving habits are fairly mild. I mostly drive in the 60's but sometimes into the 70's. I have a light foot on the throttle. My hero was the tortoise not the hare. No jackrabbit starts for me.

goslow · Mar 9, 2011

LDB said:
My driving habits are fairly mild. I mostly drive in the 60's but sometimes into the 70's. I have a light foot on the throttle. My hero was the tortoise not the hare. No jackrabbit starts for me.

70

Just kidding I only drive 60 and 64 when I am in a hurry which is rare. I run out west most of the time and I have to put up with allot of crap on the CB from the super truckers that HAVE to drive a minimum of 75!! I am surprised you already had to have it torn into. I have the 4L85 with D-max and have 420k on the clock with no problems yet and 300k+ are towing. I service the trans every 60k and use Amsoil in it. If you go with a aux cooler they are easy to install and I would go with the biggest one which is around 26k with a electric thermostat. That should keep you under 200F all the time.

LDB · Mar 9, 2011

They built that transmission just for me. I didn't really think about needing an aux cooler since I don't tow and drive gently compared to most others. With the new discussion here I'll have to give some more thought to whether an aux cooler is really needed or not.

greg334 · Mar 10, 2011

Leo,
First before figuring out if you need one, find out what caused the problem, electrical or mechanical.

purgoose10 · Mar 10, 2011

greg334 said:
Leo,
First before figuring out if you need one, find out what caused the problem, electrical or mechanical.

That does sound like a freak thing. That is a great tranny. I agree with the above statement, find out what happened. I have that trans/in one of my older C/V's behind a diesel. It does have a cooler but has never given me a problem. I kind of go over board on maintenance and service between 40 and 50k miles. The main filter must stay clear.