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Transmission cooler question

4K views 4 replies 5 participants last post by  drini2 
#1 ·
What would be the pros and cons of bypassing the radiator completely and just running the tranny fluid thru a cooler like a B&M supercooler?
 
#3 ·
Not a good practice. Been there, done that on my Ford F-150 truck. I too thought I had a better idea! As Jondotcom said, over-cooling.... The in-radiator transmission cooler works to your benefit on a cold day to warm the fluid. Without that, the viscosity of the fluid remains too high and shift performance really suffers.

Want to get really fancy? A solenoid controlled T bypass. Radiator cooler when you need it for most light duty days, and bypass it on hot towing days to keep it from hurting you.
 
#4 ·
Why would you do this? I tow 5,000 lbs 4 days a week on a commercial schedule....often 500 plus miles on hot summer weekends with our 2008 Sienna CE.

73,000 miles, towing since new.....no fluid discoloration of any kind. I never see any reports of Sienna transmissions running hot.
 
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