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8hp90 trans cooler thermostat bypass?

1294 Views 3 Replies 3 Participants Last post by  Unholy707
Hey guys, searched and found a few threads on it but really no info from guys who have actually installed it. Wondering what the general consensus is on these things now that they have been out for a while.

One one hand, it's always been common automotive wisdom that you can't get trans temps too cold. On every car i've build i've used a Tru Cool 40k or B&M 8x11x1.5 trans cooler to keep temps down and i'm usually not happy with the setup till I find a way to keep them below 180. .

On the other hand, it's hard to believe dodge engineers (or ZF) would go out of their way to engineer something in that was so restrictive and kept temps so much higher without any reason.

From what I understand, it's not necessarily heat that kills a transmission, but rather heat specifically breaking down conventional transmission fluid which affects line pressure. Modern synthetics apparently don't have significant thermal degradation of conventional oils at lower temps and can run well over 200 degrees without issues.

I keep wondering if for some reason colder fluid temps create an issue with these transmissions more than most other transmissions, hence the thermostat.
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Your theory holds merit. What makes you think they're restrictive though? Considering they have HOARDS of these out there, and millions of miles, I wouldn't use one second of brain power thinking about it. I "blew" a Grand National 200-4R many years ago from the fluid being too cool and hammering it before it warmed up.
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