My wife has a 2005 Odyssey with 50,000 miles. To date, we’ve had no problems with the transmission, but I keep reading about how the transmission on the Odyssey isn’t cut out for a vehicle that heavy. I’ve been contemplating getting a utility trailer for it (although, shockingly, my wife isn’t too hip on having a utility trailer in the driveway) and, in the course of my research, I’ve found that a transmission cooler is recommended if you’re going to haul a trailer. Is it worthwhile to install a transmission cooler even if I don’t get a trailer? Is there any downside to transmission coolers (e.g., the trans runs cold for too long)?
My wife has a 5 mile commute (10 miles round trip) and we hope to keep the van at least another 5 years.
Before we start, it’s time to change your transmission fluid. The reason is twofold: transmission fluid has a finite lifespan, and it will die at the mere sight of a utility trailer attached to its minivan home. I love minivans for their efficient use of space and command seating position, but their transaxles are never good enough.
I think every minivan needs the largest external transmission cooler possible behind the front bumper. That is almost as important as regular fluid changes. If you plan on towing anything, carrying enough people/cargo to make the rear springs sag, and/or live in a climate that’s brutal on transmission fluid temperatures, both are mandatory. I’d consider annual transmission fluid changes on any minivan that tows on a regular basis, at highway speeds.
A downside to transmission coolers? Not that I can think of. Because transmission fluid gets far hotter than engine coolant (hence why many tranny coolers are just a heat exchanger inside the engine radiator) the odds of being too cold aren’t a big concern. But if you aren’t a Houstonian like yours truly, maybe you will need a radiator block-off pad for your front bumper…in the Yukon Territory.