Another AT542 question

[jauguston]

Do any of you have any technical knowlege of how the shifting is controlled on this transmission. Not the manual gear shifting with the shift lever but what controls the downshift from 4-3 when pushing the throttle down. I am curious if that shift signal is electric. If it is I would like to figure out a way to send that signal when I release the throttle pedal to 0 throttle. If that can be done it would help with the no engine hold-back going down hills. The transmission would go to third gear when the throttle was released without having to select third manually.

Jim

 

[spg]

The shift points are controlled by the govenor, Modulator and transmission line pressure. I don't know enough about them to tell you how to keep it in 4th after you let off the throttle.

I have played with mine to make it upshift earlier by heavier weights and springs in the govenor and a spring between the modulator and valve. But I don't know how much it affects downshifts.

 

[jauguston]

I don't want it to stay in 4, I want it to downshift to 3 when the pedal is at 0 throttle without me having to manually shift to 3.

I have done some more research and it seems likely what I want it to do can be done. We are leaving for a week trip Thursday to Eastern Washington so any more progress will have to wait.

The transmission does not have a true modulator. It has a electric solenoid that is either on or off. Controlling that solenoid may well be the way it is done.

Jim

 

[spg]

Please keep us updated as to what you try and how it works. Thanks.

 

[spg]

Any updates on this project yet?

 

[jauguston]

I have been experimenting with several ideas and have not yet got what I want.

Jim