Overcool a transmission.

[Thingfish]

Originally Posted By: rshunter
Originally Posted By: mechtech2
Install the aftermarket cooler like they all recommend.
That is, IN lINE. IN SERIES with your present tank cooler.
The tank first, then the new one, then back to the transmission.

The problem is that he can't. As he pointed out, he's replacing the radiator with an aftermarket unit that doesn't have an integrated cooler.


That is correct. Thank you for addressing that.

 

[mechtech2]

Originally Posted By: Thingfish
Originally Posted By: rshunter
Originally Posted By: mechtech2
Install the aftermarket cooler like they all recommend.
That is, IN lINE. IN SERIES with your present tank cooler.
The tank first, then the new one, then back to the transmission.

The problem is that he can't. As he pointed out, he's replacing the radiator with an aftermarket unit that doesn't have an integrated cooler.


That is correct. Thank you for addressing that.


Then get a BIG aftermarket cooler! Overcooling is easily controlled with a piece of cardboard [or similar] over it in winter

 

[cbear]

Aren't plate style coolers suppose to self regulate?

 

[Thingfish]

Originally Posted By: mechtech2
Originally Posted By: Thingfish
Originally Posted By: rshunter
Originally Posted By: mechtech2
Install the aftermarket cooler like they all recommend.
That is, IN lINE. IN SERIES with your present tank cooler.
The tank first, then the new one, then back to the transmission.

The problem is that he can't. As he pointed out, he's replacing the radiator with an aftermarket unit that doesn't have an integrated cooler.


That is correct. Thank you for addressing that.


Then get a BIG aftermarket cooler! Overcooling is easily controlled with a piece of cardboard [or similar] over it in winter


Sounds like a plan, fluidyne makes a long one that would fit nicely, and look like a front mount interfooler. And living in vegas, I do not see much cold weather, and I am putting a relatively large amount of power though this trans.

 

[Nick R]

Originally Posted By: rslifkin
It's tough to overcool an auto. Some newer computer controlled ones will try to warm themselves up, killing fuel economy. However, many (such as the one in my Jeep) really don't care much.

The only time it might be overcooled is highway cruising with the torque converter locked in the dead of winter , and even then, I've had no issues with mine (11x11x3/4" external cooler, rad cooler bypassed). When the converter is unlocked, it's making plenty of heat. I don't really like those thermostats, as 180* is warmer than most transmissions need to run. If I could find a 150 - 160* t-stat for one, I'd install it. Otherwise, I don't want my transmission running 190* all the time.

After a highway run in the winter, the pan is lukewarm to the touch. Only if the fluid is below about 30* does the transmission feel weird (hangs in low gears, feels sluggish). Once the fluid warms up a bit (even if it's technically too cold), it shifts and drives normally. It shifts just a hair firmer with the fluid good and warm.


My one big complaint about my focus is that when cold, the TC refuses to lock up until it's been driven for a while. The expedition, and even my grandfathers new escape, lock up immediately when they can. It's just annoying.

 

[Jim Allen]

My '05 F-150 4R75E needs to reach 90F (IIRC) before the converter locks. Our 2000 Honda has to reach a present temp before it locks (but I don't know what that temp is, I just feel the delay).

 

[btanchors]

Reading this discussion, I note with interest as I read the manual of my new Toyota Tundra 4x4 that the extra transmission oil cooler has a thermostat built in, so the fluid warms up more quickly when it is cold. Once it is warmed, the fluid is re-routed to the cooler for extra cooling, such as would be needed when towing a trailer. The reasons mentioned by the manual for this are to improve fuel economy when the vehicle is cold.

Even more interesting, this vehicle came with a separate temperature gauge (not an idiot light) just for the transmission - so it has a temperature gauge for both the engine AND the transmission. Never seen a vehicle come with this from the factory before.

 

[rslifkin]

The Tundra is one of the very few to have a trans temp gauge stock. It's a nice feature.