'89 744 109k miles

Just recently, my OD solenoid became intermittent in that with a HOT engine, it would work, but with a cold engine (less than 15m running or so) would not.

Up until then it was flawless. One day flawless, the next, awful.

I checked for voltage at the connector underneath, and it was fine, but the solenoid would only sometimes activate.

I read the FAQs and it recommended dropping the cross member and dropping the tail of the tranny to get at it. I was working on jack-stands under the front alone, and just didn't want to add dropping the tail to do the job if it could be avoided.

I found that by dropping ONLY the shift rod at the trans lever (The pin was stubborn in the fork, but w/ some PB Blaster and Vise-Grips it came out-Be careful not to lose the "C-Clip" that retains the pin), I had PLENTY of room to get my arm up along side the trans from the rear to get that 12mm head bolt loose, and from the front to reach back to get the front bolt. NO NEED or reason to lower the transmission at all as far as I would see.

I did use a 12mm flex head Gear-Ratchet for the job, and it DID make the job easier, but it was NOT mandatory by any means; a box wrench or non-jointed Gear-Wrench would have sufficed. The solenoid came up and off easily, but the O-Rings remained on the trans case.

Using an aux bar battery, the solenoid worked flawlessly on the bench, with a consistent loud "Click," and spraying brake cleaner through the unit proved it was working as advertised.

The contact surfaces (used as the ground) where the solenoid was in contact w/ the trans case weren't shiny, and either were the retaining bolt threads, so I made the assumption that the problem was a poor ground.

I cleaned everything up w/ a wire bush, and even ran an EXTRA ground wire from under one of the solenoid mounting bolts to under the 6mm bolt holding the wire bracket (about 6" forward of the solenoid) to the trans case. I did this because I didn't want to clean the trans mounting pad and possibly scrape dirt into the passages, and felt that this extra wire I might bypass the problem down the road.

I coated all hardware w/ anti-seize to exclude moisture, and installed new O-Rings onto the solenoid w/ a couple dabs of contact cement to hold them onto the solenoid so they wouldn't drop off when re-installing the solenoid, and bolted the solenoid and the wire-bracket in place, then re-attached the shift rod , pin, and "C-Clip."

Unit now works flawlessly and every time. I would guess I am not the only one who experienced non-operation due to a little corrosion even in a mostly corrosion-free car.

I hope this gives those with similar problems the impetus to get under and do the job, and hopefully have similar success at zero cost.

Bob