How to mod hydraulically controled AT ?
 

Hey guys

I have a Citroen ZX with a 4 speed automatic gearbox, it is a ZF 4HP14 completely oldschool hydraulic control, no ECU.

The transmission shifts into 4th at about 70 Km/h but it can mantain it down to 60km/h, I was thinking of finding a way of making it shift up sooner.

Should I be loking for a vacuum line to tap into ? or adjust the kick down cable a different way? (maybe its not just kickdown)

Or is it really a no go and only real way to do it would be to change the valve body ? (Wich obviously is not practical).

Thanks for the help

It looks like a cable only trans. Most cable controlled transmissions use the cable to control line pressure. I would loosen the cable and see if it upshifts sooner. You can also go inside and play with the governor springs.

I really wouldn't mess with the transmission shift points unless you have a trans temp gauge. The sooner it shifts, the more it will drop in and out of overdrive, thus 'slipping', the more heat you make.

OK thanks guys I will see what I can do.