Installed Aftermarket Transmission Cooler

[Sandberm]

...on my 08 Chevy 1500 with the 5.3 yesterday. It already had a smallish one and i just installed the new one in line with it.

A little history. I bought this truck last summer to pull our 20 ft travel trailer. The tt is roughly 4000lbs max. Ive put 4000 miles on the truck since. I'm guilty of not paying attention to the transmission temp as I have to push in the button to change from odometer to tranny temp so I do not really have a grasp of what is normal over the course of years and situations.

So anyways, last fall when I went on a camping trip in 50 degree temps pulling my tt, normal transmission running temps on flat ground was in the 180-190 range but got to the 220s in prolonged uphill pulling. This concerned me as it was only 50 degrees out. Whats going to happen when its 90+ degrees out? Ive never towed the tt since. The trucks everyday engine temp is 210.

So, on Sunday I made it a point to pay attention to the tranny temp pre-install of the cooler, 125 to 130 in 45 degree weather on a 35 minute one way drive. Installed the new cooler yesterday and went for a drive, now its at 110. Seems kind of cold but what do I know?

Whats your experience with tranny coolers? How much temp drop? Is it possible to be too cool?

[Special T]

Heat kills auto transmissions. it was $ and time well spent. Id also do a fluid change and filter.
I hate auto transmissions especially for  a tow rig.

[KFhunter]

I won't let a tranny get over 210 before I pull over,  anything 220 and up it goes down fast, exponentially fast.  Honestly I start looking for a place to pull over at 190 then at 200 I'm really looking because it's only going to climb from there.   If I'm right near the top I'll chug up the hill


I've got my transmission cooler tucked up under my bed above the drive line, has its own fan.  I still use the factory cooler too up front.


I don't think you can run a transmission too cold      they operate them in sub-zero temps, fluid pressures might be a tad higher but ya..110 degrees I'd run that all day long and smile about it. 

[Magnum_Willys]

Sounds like its working perfect!   Probably will warm on hills and load.   Tru-cool 40k with thermostat is the best but overkill for 4k trailer.

[MR5x5]

Yes it is possible to be to cold.  Would be great to keep at 150-170 F under all conditions.  The fluid needs to be able to boil off condensates.  Does your new cooler not have a thermal bypass valve?

[Sandberm]

Yes it is possible to be to cold.  Would be great to keep at 150-170 F under all conditions.  The fluid needs to be able to boil off condensates.  Does your new cooler not have a thermal bypass valve?

No. I bought a Derale 8000 series cooler, part #13504 from etrailer.com. Nothing fancy.

I have no experience in adding transmission coolers to draw on. I did a google on that valve you mentioned, makes sense.

[KFhunter]

Yes it is possible to be to cold.  Would be great to keep at 150-170 F under all conditions.  The fluid needs to be able to boil off condensates.  Does your new cooler not have a thermal bypass valve?

like hydraulics....