Does my radiator need to have a transmission cooler?

[jimbonice]

If you check with the shops that build hd tranny's for towing, they recommend to add an external cooler to the factory cooler. Some won't warranty them without the original factory cooler installed in addition to an external. As I stated the factory cooler is pretty efficient and hard to beat. My hemi Ram has both an external and rad cooler from the factory, a lot of modern trucks with the heavy duty cooling options do. There is zero harm for a transmission to operate at normal coolant levels, they're designed for it. The harm is in elevated levels to the point fluid starts to cook and allow clutches, seals etc. to cook. 190 degrees is not the temp they do this. Just my 2 cents and change.
Cheers

[463]

heres a link t a chart http://www.txchange.com/heatchrt.htm

[bigblock73]

Originally Posted by jimbonice

If you check with the shops that build hd tranny's for towing, they recommend to add an external cooler to the factory cooler. Some won't warranty them without the original factory cooler installed in addition to an external. As I stated the factory cooler is pretty efficient and hard to beat. My hemi Ram has both an external and rad cooler from the factory, a lot of modern trucks with the heavy duty cooling options do. There is zero harm for a transmission to operate at normal coolant levels, they're designed for it. The harm is in elevated levels to the point fluid starts to cook and allow clutches, seals etc. to cook. 190 degrees is not the temp they do this. Just my 2 cents and change.
Cheers

You are exactly right, always run your external cooler with the factory one. I have heard this MANY times, in fact, the place I got my OD trans from recommends it as well. Also, for those running only the aftermarket ones, these are often time cheap units as well, and can break down just as easily...then what do you do? IMO, two can't hurt anything, why not run the fluid thru both? I have had more vehicles in my life than I can count, with most being over 10 years old and having over 100K on the odometer...none had aftermarket coolers...and none had transmission problems.