Hi everyone,

I am curious to know the normal functionality of the ZF 4HP22 transmissions in our trucks. Is it normal for the torque converter to be heard when shifting from 1st to 2nd? Sometimes when shifting when the engine and transmission are cold it shifts very slowly, but when warmed up it does not. Also, is 3000 rpm normal when going 80 mph?

 

tire size will affect RPMs at a given speed. what size tires are you running?

 

3000 at 80 is pretty close to normal, you should be able to notice rpm drop for each gear shift as well as torque converter lockup.

 

Might want to see if the trans will take any fluid. Or drain what you can and refill till it starts running out the fill hole.