Automatic Transmission Issue

[mumbaipete]

I've got a 1989 635csi Highline auto. I'm having an issue with the transmission. When I'm driving at a constant speed (40, 50 ,60, 80 whatever) it drops out of 4th into 3rd then takes ages to jump back up but then falls out again quite quickly. Trying to get it sorted with an automatic transmission specialist but none of the diagnostic computers they've tried on it will communicate with the car's diagnostic computer. Has anyone else had similar transmission issues or do you know what type of diagnostic equipment will communicate with a Highline?

[miklilmag]

Hello,
Specialist, not so special, not knowing about your ZF transmission,

Some suggestions:

..Low on fluid??

...sport mode selector switch?, Spilled a beverage lately?
unplug and go for a test drive,

..Plug-in by tranny?..loose connection? Maybe!

..Valve for 4th. might be stuck,?.. remove, rebuild Valve body! ...Very likely!

..Clutch pack for overdrive is going out, reverse and first are going soon, rebuild all!

Shogun on bimmerforum, e32, he has done some write ups on zf4hp22eh.

Good luck!
Franke

[mumbaipete]

Thanks Franke

Hello,
Specialist, not so special, not knowing about your ZF transmission,

Some suggestions:

..Low on fluid??

...sport mode selector switch?, Spilled a beverage lately?
unplug and go for a test drive,

..Plug-in by tranny?..loose connection? Maybe!

..Valve for 4th. might be stuck,?.. remove, rebuild Valve body! ...Very likely!

..Clutch pack for overdrive is going out, reverse and first are going soon, rebuild all!

Shogun on bimmerforum, e32, he has done some write ups on zf4hp22eh.

Good luck!
Franke

[mumbaipete]

Thanks for the suggestions. Will let you now what I eventually find out.