I can vouch for that. Before I added the auxiliary cooler last August, my
505 V6 with ZF 4HP22 trans would overheat. Fluid would leak out all over
the road. Since I installed the cooler, I have not had any transmission
problems. The cooler consists of a heat exchanger, like a mini-radiator,
spliced into the transmission return line (from the car radiator back to
the transmission) I use semi-synthetic ATF. The transmission has not leaked
a drop since and shifting is smooth but distinct. I plan to add in an extra
filter and transmission temperature guage.
I highly recommend an auxiliary cooler for anyone with a ZF 4HP22.
Gordon Brown
Whitby, Ontario