I have been fixing various problems with my 89 635CSI with the help of everyone at this forum, and posting results of my repairs. Now for a real problem now that I have it on the road I realize that is shift real hard (auto)
it is in the economy position and bangs no matter the throttle position. Does anyone have any ideas?

I have been fixing various problems with my 89 635CSI with the help of everyone at this forum, and posting results of my repairs. Now for a real problem now that I have it on the road I realize that is shift real hard (auto)
it is in the economy position and bangs no matter the throttle position. Does anyone have any ideas?

When's the last time it had fresh fluid?

I am flushing it out today and replacing filter, and fluid with Mobil 1 multi vehicle fluid. I'll let you know how it turns out

Well, did the flush and filter change. It shifts a little better. but not much and it shifts late. it doesn't go into overdrive until it hits 60 MPH is there a flash for this transmission computer? today I am going to try the Throttle Position Senson and see I can make a change.

Today I adjusted the TPS and still shift near the same speed.