tranny questions??????

[caspear78]

ok all you tranny guys, what would u rather use to cool ur tranny the stock in radiator cooler or would u rather use an aftermarket cooler, what are the pros and cons to both, and also where would a good place to be to place an aftermarket cooler,,,,,,mark

[Tx Firefighter]

In-radiator cooler, no doubt.

The radiator cooler does something just as valuable as cooling the fluid, it keeps it warm. ATF can easily be too cold as well as too hot. That's why the engineers put them there. It regulates the heat within a range.

[bigjimzlll]

it depends on your intended use...if you are going to race it at all...then you dont want to heat your tranny fluid. Ofcourse in you neck of the woods...you probably need as much heat as you can get

[caspear78]

im thinkin about leavein it stock and not usein the aftermarket cooler, thanks for the tips and advice on the matter,,,,,,,,mark

[toddtheodd]

I've ended up using an after market cooler due to the transmission-to-radiator threads stripping on the trans lines. It was either pay a "buttload" to replace the radiator, or just get the aftermarket kind and run some hoses.
I haven't had any problems with it yet.
I've got it mounted in front of the radiator.
Todd

[4x4Poet]

Physics play a large role in this comparison. The internal rad cooler has the advantage of having coolant in direct contact with the tubing of the cooler coils. Since at or near engine operating temp the coolant remains at a lower temp than the tranny fluid, the cooler coolant in effect "pulls" the heat out of the tubes which absorb the heat out of the tranny fluid because the outside of the tubes are kept at a lower temp than the incoming tranny fluid. So, at engine operating temps, the heat transfer can only go one way. TxFf well covered the scenario when the coolant is warming faster than the tranny fluid as the engine is advancing from initial, cold start temp to operating temp. Opposite direction on the heat transfer then.

Aftermarket tranny coolers that use airflow to cool don't transfer heat as well because gaseous, even humid, air cannot "pull" heat away from the aircooler as well as liquid coolant can surrounding the tranny cooler with the radiator. It's a molecules per square inch kind of thing that enables densor liquid to cool faster than not-so-dense air, given both have a lower temp than that which is to be cooled.

[mrein3]

A couple of years ago I swapped my 3-speed manual 4x4 to a 3-speed automatic (th350). While doing the swap I bought a transmission temperature gauge and installed the temperature sensor in the transmission while the th350 was on the bench.

After I put it all together I did NOT install my external transmission cooler and did a test. I had a fishing tournament on the river about 100 miles from my house. The first trip I made pulling my 3000 pound Triton and noted the temperature. When I had to drive through Stillwater, a busier small town, I found my self in stop and go traffic. My transmission heated up to 200 to 205 degrees at one red light. It quickly cooled back down when I moved again but that is getting quite hot.

One evening that week I installed an aftermarket cooler. The following weekend I made the same trip. I had the same traffic. The ambient temperature was similar. It was around 70 degrees both days. In the same stop and go traffic it never went over 185.

To make a long story short I would install the aftermarket cooler. No doubt.

Since you are up north just make sure you plumb it so the hot transmission fluid goes to the external cooler, then the in-tank radiator cooler, then back to the transmission. That way you won't get the fluid too cold which is a problem too.

[caspear78]

thanks again for the replys and the advice,,,,,,,,mark