Thread: Transmission cooler setup - should I change it? What temps are too hot?

Ive got a pretty decent 26000gvw trans cooler (that Trannyman recommended). I put it here so that the fans sucking through the radiator would also suck through the trans cooler - it also gets air from the passenger side grill. Here is where it is attached:


My temps get pretty warm when Im doing WOT runs and stay very consistent while Im cruising. At wot the temps go to about 95-100c or 200-210 degrees fahrenheit. After the temp gets up there it usually doesnt come back down unless I do quite a bit of cruising with the TCC locked or I have to park the car and turn it off.

It takes a long time for my temps to get up to ECT temps so I know the tranny cooler works well. Trans temps at cruise are usually a fairly consistent 80-85 celcius or 180-185 fahrenheit. I just cant keep the temps down while going WOT which brings me to my question:

Should I get a fanspeed switch from ZZP and turn my fans on when going WOT to cool the tranny cooler?

Should I get a seperate fan thats activated by the trans temperature? If so, any slim fan with a high flow rate that you guys recommend?

The trans is being cooled ONLY by the trans cooler - should I route the lines through the stock cooler as well? Would it help any?

What are acceptable transmission temperatures when cruising and WOT? Ive seen stock trannies get pretty damn warm so Im assuming mine are fine - but Ive always been told the cooler the better.

Originally Posted by Tengis

The trans is being cooled ONLY by the trans cooler - should I route the lines through the stock cooler as well? Would it help any?

That might make it worse as the hot coolant in the radiator warms the fluid.

ttt

If you have room for a small fan that would certainly help when not cruising down the highway. Your converter must be fairly loose for the temps to sit that hot after a hard run. You can try putting the radiator back in the loop but Im not sure it is going to be of much benifit, but hey if it works it works and if not then you just proved to yourself that it isnt benificial.

FYI, my tranny temps and how they react are exactly like yours. I don't have nearly the weight nor the power you do. I had a small B&M cooler, which is a very good cooler, but decided to remove it. I wanted to be sure the tranny warmed up as quickly as possible. It did help to cool down on the highway, but still took a while. I did recently discover that the optimal operating temp for a transmission is about 190*. So, 200* really isn't that bad. I think running through the factory cooler is a good idea. The fluid should run thought the factory cooler last. The engine heats up faster than the tranny. So a hot radiator will help to heat the tranny up fast. With a 180* stat, tranny temp will try to remain around there. Most cars have a 195* stat, so a temp of 200-210 would be totally fine. If anyone is interested, I have the BIG B&M style cooler I would be willing to sell. It measures roughly 11x12x1.5 inches.