DEX-COOL, Conventional Green, & G-05... My Experiences

But... you CAN overcool an engine and affect performance. Can you overcool a tranny?

Not really. There's no source of moisture or volitiles to contaminate auto tranny fluid as there is in an engine (combustion blow-by) so unless you make a habit of fording streams, you don't need the oil to get hot to drive away accumulated moisture.

I suppose that if you lived in a VERY cold climate and, for example, your transmission fluid never got above freezing, you might have a problem. But as long as it gets to "room temperature" I'd think it should be fine.

Some transmissions will not lock the torque converter untill they see a certain trans fluid temp. So I'd have to say yes, it is possible to overcool a transmission. Bob

My Saturn SL2 won't shift into 4th gear until it reaches an operating temperature on cold days. So, on really cold days, the engine rpm's can get up there in the morning commute.

later,

tom

Ensure it will handle the pressure.

ATF coolers don't run at nearly the pressure that engine oil does.

I think it is actually going into 4th gear and it's the torque converter lockup that you are not feeling. They let the converter slip to purposely build heat in the trans until it comes up to operating temp. Bob