Author Topic: Auto transmission three position solenoid  (Read 1704 times)

Jonny B

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Auto transmission three position solenoid
« on: December 30, 2017, 21:53:29 »
Thanks to Mr. Alexander, I was able to obtain a replacement three position solenoid (the one on the top of the auto trans). This has been installed in the car, and the car now downshifts smoothly for stopping, and the kick-down for works as it should.

My friend Barry and I took the old solenoid to see what we could determine while it was on the bench. Note - it did function before it was installed earlier this summer during my transmission rebuild. But after driving it, no kick down, checked again, and it is sticking in place.

While on the bench, when we applied power (don't remember which wire this is, but does not really matter for the purpose of the test) the pin would retract, and sometimes stick. So we lathered it with WD40 and got that to work reasonably well. When we applied power to the other lead, the pin would fully extend, but then stay in position when power was taken off. We could easily push it back into position, try again, and the same thing.

In looking at the device, there appear to be three pins holding the cover plates in place on each end of the solenoid. It appears that these would have to be drilled out to get access to the interior windings. You can see one of the pins in the third photo.

Has anyone every tried to do this, and if so, what or how did you go about. And more importantly were you able to do anything to fix the solenoid??
Jonny B
1967 250 SL Auto, DB 568
1970 280 SL Auto, DB 904
1966 Morris Mini Minor