Bypass Transmission Cooler

[Oldswagon]

I am looking at adding an auxiliary transmission cooler to a Ford C6 tranmissoon with a higher than factory small converter. I was looking at using one of Hayden's Thermal bypass coolers. I know the bypass works by ATF viscosity and not an actual temperature. However, does anyone know what the approximate temperature range these bypasses activate?

I am thinking of using a Hayden 699 which may be overkill, especially if driven in cool weather, but that's where think the bypass will help. I am also planning on running it in series with the factory in rad cooler. The engine runs a 180 thermostat and runs pretty near there. The trans is running too hot though due to the converter.

 

[spasm3]

When i was towing with a 1/2 ton avalanche, I went with a Trucool LPD. It has the most cooling ability. I has the return line go into the radiator for the first temp drop in the rad, then out of the rad and to the Trucool.

IIRC it was @clinebarger that recommended that line of coolers. Now they have a TRUcool Max with cools even more than the Trucool. I never worried about a thermostat or thermal bypass.

https://www.trucool.com/EN/Products/Tru-Cool-LPD.aspx

https://www.trucool.com/EN/Products/Tru-Cool-Max.aspx

 

[spasm3]

Here is what it did on my previous truck. This was 1hr into a trip. Going up Black Mountain 6% grade for 5 miles temp was 174f at the top of the mountain, ambient temp was 84F.

 

[clinebarger]

I am looking at adding an auxiliary transmission cooler to a Ford C6 tranmissoon with a higher than factory small converter. I was looking at using one of Hayden's Thermal bypass coolers. I know the bypass works by ATF viscosity and not an actual temperature. However, does anyone know what the approximate temperature range these bypasses activate?

I am thinking of using a Hayden 699 which may be overkill, especially if driven in cool weather, but that's where think the bypass will help. I am also planning on running it in series with the factory in rad cooler. The engine runs a 180 thermostat and runs pretty near there. The trans is running too hot though due to the converter.

Every thermostatic bypass I've seen be it Oil or ATF uses a wax pill just like a coolant thermostat.

 

[Marcozi]

Here is what it did on my previous truck. This was 1hr into a trip. Going up Black Mountain 6% grade for 5 miles temp was 174f at the top of the mountain, ambient temp was 84F.

View attachment 292077
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That's an amazingly good temperature for that run.

 

[supton]

Here is what it did on my previous truck. This was 1hr into a trip. Going up Black Mountain 6% grade for 5 miles temp was 174f at the top of the mountain, ambient temp was 84F.

View attachment 292077
View attachment 292078
View attachment 292079

Was the torque convertor locked up? I'm guessing the engine was spinning at a good rpm, so not locked it would not be high slip, but it would have still made some amount of heat, working hard up a hill.

 

[spasm3]

Was the torque convertor locked up? I'm guessing the engine was spinning at a good rpm, so not locked it would not be high slip, but it would have still made some amount of heat, working hard up a hill.

Truck had a towing converter, but I'm not sure that tow/haul mode let's the converter lock.

 

[Oldswagon]

Every thermostatic bypass I've seen be it Oil or ATF uses a wax pill just like a coolant thermostat.

This is more of a pressure bypass, that supposedly will go into "bypass" when the transmission fluid is cold but open when the ATF heats up. It's just a basic reed valve. I also like that it would also work as a pressure relief like in an oil filter.

https://patents.google.com/patent/US8267162B1/en

https://www.haydenauto.com/media/9055/bypass-transmission-oil-cooler_flyer_2022.pdf

I am just looking to see if anyone has actual numbers to show what temperature range this bypass works at. Obviously, newer thinner ATF will make it operate at lower temps, but this is for an old transmission with Dexron/Mercon.

When i was towing with a 1/2 ton avalanche, I went with a Trucool LPD. It has the most cooling ability. I has the return line go into the radiator for the first temp drop in the rad, then out of the rad and to the Trucool.

IIRC it was @clinebarger that recommended that line of coolers. Now they have a TRUcool Max with cools even more than the Trucool. I never worried about a thermostat or thermal bypass.

https://www.trucool.com/EN/Products/Tru-Cool-LPD.aspx

https://www.trucool.com/EN/Products/Tru-Cool-Max.aspx

It appears that the basic Tru-Cools aren't available anymore, but the Hayden chart lists the Tru-Cool part numbers on their listing. See in the chart:

 

[supton]

Truck had a towing converter, but I'm not sure that tow/haul mode let's the converter lock.

Tow/haul mode should make it more aggressive on lock-up, and to kick down sooner. As opposed to running unlocked (and making heat).

Some transmissions won't do lock-up in all gears. My Tundra wouldn't do it in 1/2/3 but would in 4/5/6.