Allison 5sp: Why mount tranny coolers the way they are???
- Thread starter MAXX IT OUT
- Start date
My only assumption is air could get trapped in the top parts of the cooler, thus reducing it's efficiency.
On the '01 through the '04 LB7, I really don't think it matters because of a constant 80+ psi of pressure in the cooler flow. You won't get any air pockets. In '04.5, Allison started using the G solenoid which dropped pressure 150psi at below 8% throttle to take the load off the pump and cool better at idle. There might be a possibility for some air to get in the cooler since the cooler line will hardly dribble at idle and go full line pressure at above 7% throttle. You will notice that from '06 on, the coolers fill and exit from the top. I'm assuming they want to make sure there is no air pocket inside. Either way I don't think it amounts to a hill of beans which way you mount it.
The B&M cooler does not work for CRAP mounted like GM does. I ran one on my BURB and only the bottom 3 inches of the 8 1/2 inches of cooler ever got warm(makes no sense considering GM used the same exact coolers for trans coolers for years and mounted them the same way). My EARLS cooler warms up a lot more evenly than the B&M did mounted upside down.
When the fluid returns from the cooler to the transmission, doesn't it just go into the pan to be mixed with all the other fluid held there??
No, it goes into the lube circuit and lubricates the gear train. Then it dumps to the sump.