Transmission Solenoid Repair

[KUMARB]

Has anyone repaired/overhauled the double acting solenoid mounted on the top of the automatic transmission of a 280SL?

While restoring my car, I noticed the linkage between the solenoid and the automatic transmission pressure regulating lever was broken. I am not sure yet why it broke or the mechanic simply disconnected it. I have removed the solenoid from the car and tested it. The solenoid sticks and does not return to the center when de-energized. I opened the top part of the solenoid, cleaned and greased it. The solenoid seems to work a little better now but still sticks somewhat. The electromagnetic part of the solenoid is sealed in a steel casing and was perhaps not meant to be repaired.

New solenoids are available at the local MB dealer for $470 each. Are there cheaper versions from OE M's? My efforts to repair the existing one to save money are basically futile?

Your helpful comments will be very appreciated.

Thanks,

[JosephBach]

We had some problems with the solenoids on my sons 230sl.  We had heard that you
could soak them in acetone overnight and it should dissolve all the fine crud that you cannot get to.
So we gave it try and we have not experienced any troubles at all.  After soaking them we let them
air dry for a good two hrs.  I then electrically tested them before we reinstalled them.  You probably
need to actuate them several times as to make sure they have full travel.  Good luck!

[JosephBach]

I forgot one more thing.  As an industrial electrician, grease on a solenoid can end up to be your
worst enemy.  It will act as a dirt magnet causing it to be slow acting and eventually overheating the
electric coil, causing it to short out or open the windings within the coil itself.

[JosephBach]

The air dry time in Phoenix is considerably less than in Jacksonville so be cautious.  You may want to add some more time on.