Big Truck Tranny Coolers

Tobster317

Expert Expediter
Owner/Operator
Has anyone in a str8 truck or bigger used an aftermarket tranny cooler. If so did your truck engine run cooler after the tranny cooler was installed? Basically I'm trying to get the truck to run cooler, was wondering if eliminating the tranny fluid from the radiator did anything. Thanks.
 

Slo-Ride

Veteran Expediter
Has anyone in a str8 truck or bigger used an aftermarket tranny cooler. If so did your truck engine run cooler after the tranny cooler was installed? Basically I'm trying to get the truck to run cooler, was wondering if eliminating the tranny fluid from the radiator did anything. Thanks.
Assuming your truck is running on the warm side? (Hotter then normal.)
Have you looked for the cause, if the transmission cooler was factory installed there really shouldn't be any reason that would make the eng run hotter. A automatic trans with problems just might.. I would search out any other possible proplems before by-passing the factory system. Could be something as easy as a dirty radiator.
 
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Joe Mavrik

New Recruit
Owner/Operator
Assuming your truck is running on the warm side? (Hotter then normal.)
Have you looked for the cause, if the transmission cooler was factory installed there really shouldn't be any reason that would make the eng run hotter. A automatic trans with problems just might.. I would search out any other possible proplems before by-passing the factory system. Could be something as easy as a dirty radiator.

First thing I would do is pressure wash the radiator. You'd be surprised what comes out.

After that, your automatic transmission lines might be too big for any normal automotive trans cooler to handle.

Certain heavy truck shops carry semi specific coolers, but make sure your trans is in good enough condition before spending the big $$$!!!
 

Tobster317

Expert Expediter
Owner/Operator
Thanks guys but I know and have done all that. The Hino in the summer just runs warm and I like to drive 65-70 mph. But in the summer it's just runs warm at that speed have to keep it under 65. I was just wondering if anyone did it. I have found the cooler it's $650. I just don't want to spend the money if I'm not sure if it will work.
 

piper1

Veteran Expediter
Owner/Operator
Define "warm"....210F is the new 190F nowadays.

If your transmission is operating properly, going down the highway at 65 the torque converter should be locked up and in this state, the transmission doesn't generate that much heat...your cooling system should be able to handle it easily. If you are sure the rad is clean and in good shape internally (corrosion, sludge etc) then I'd be looking at the fan or thermostats for weakness or improper operation. I'm assuming the truck didn't run warm before and that this is a new to you problem....reason I say that is some trucks that the OE designs as local delivery trucks that end up on the highway don't have enough cooling capacity right from day 1. I had several International 4300's that had overheating issues right from new when they drove in or out of the city on the highway but would run all day in the city traffic with no issues. Internationals fix was to run the rad fan constantly (killed mpg's). They were the last International straight trucks I ever bought lol. Some small trucks just don't have enough cooling capacity to be run on the highway all day pushing a full size box through the air.

There are companies that made higher capacity radiators that will fit in the space provided (Detroit Rad is one)..not sure if they do Hino's.
 
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Joe Mavrik

New Recruit
Owner/Operator
Just to throw it in there.....

You could always add an external filter unit split from one of the trans lines. I have added them to oil systems using a 2-3 quart filter and hung it low so it catches wind. That might help reduce temps under load and not cost several hundred dollars.
 

Tobster317

Expert Expediter
Owner/Operator
OK AN UPDATE:

I found the charged air cooler to be bad. Went from Daytona beach to Charleston SC. Only 2K in weight and about 90 degrees outside. No running hotter. Then I get a load SC to Waterloo IA, 8200lbs. 1100 miles. Take 26 to 40 to 75. We all know the hills and mountains throw NC, TN, KY. Not one problem of running hot. Only one or two of the larger mountains it got up to the last white line. Ran 65 into 74 with the cross wind on 74. NP. Ran 74 into 80 head wind NP and that's with 8200lbs on the truck. I ran 65-67mph the whole trip where the speed limit would let me. The guys with the smaller str8 truck engines know what Im talking about. The temp. Was good the whole trip.
 

BobWolf

Veteran Expediter
Owner/Operator
Don't waste your money, the transmission cooler will do very little to nothing to cool the engine.
What are the RPMs at? usually anything over 2000 will result in excess heat poor as well as mileage. I'm almost willing to bet money on that this most likely the cause of your high engine temps..

Also if your equipped with an Allison make sure there are no hidden ABS codes as the transmission wont go into lockup this results in the transmission and engine running hot. I would also find out if the injectors are getting tired and not closing properly.
Check the fan and fan clutch for operation. Drain flush and refill the cooling system, stop by home depot and pick up a few cans of A/C condenser cleaner. on a cool engine use a garden hose to spray out the ac condenser radiator, charge air cooler, and you should have a factory transmission cooler. while wet spray the cleaner let it work for a few minutes and spray it out with a hose.
check your radiator, and A/C condenser if they are full of bugs or the fins are smashed flat this will restrict air flow. Check the A/C charge as well. If the fan is electronically engaged the A/C might cause problems.
 
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