'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

FWIW I went around the block also with the electrical, what fixed it was the official Brickboard tranny flush with the bucket and hose at the radiator cooler. Years latr still working fine.

Not quite sure what you're saying...

You mention that you went around the block with electrical, but the problem was (I presume) bad fluid (or contaminants that the fluid flush removed).

Are you saying that the contaminated fluid prevented a perfectly good solenoid from shifting properly, and after a fluid change your old intermittent solenoid was again working perfectly?

Thanks,
Bob

That is what I am saying, the OD operation went from unreliable to reliable. One would think it would either work or not work, yet after the flush, the full Brickboard type flush, it worked and continues to work reliably without the problem of sometimes not going into overdrive when it should.
As far as the solenoid wiring goes, the external wiring can be easily redone using vacuum hose to replace the wire protector as it gets oily under there. Any open solenoid should have the cast rubber cap carefully pried or cut away and the wire connections beneath checked as I have recovered two solenoids that way. Keep the wire crimped on the arm staked to the center and smear all with black RTV to complete repair after resoldering the broken wire.

If I hadn't been where I had limited resources to work on the car with I'd have messed w/ the unit more.

It pained me to sacrifice a possibly salvageable unit.

Hope that solves it for you.

I had some pretty similar hope for one of mine that acted up dependent on temperature -- figuring I'd get to the bottom of it one day and find where the break was. Mine was inside the coil winding. Notes on Automatic OD Solenoid Failure Analysis - (not repair instruction)

By the way, it took me a lot of reading to ascertain you were working on an automatic. The year should have clinched it for me right away.
--
Art Benstein near Baltimore

I went to buy some camouflage trousers the other day but I couldn't find any.

OK, You can say, "I told you so."

After removing my solenoid and cleaning and duplicating the ground, and finding it worked flawlessly for several days, I thought I had it "knocked."

We towed the car 1100 mi to where it will now live at our vacation condo (where I have no tools or facilities to work on the car, and it's against the HOA to even add oil to your car (just opening your hood violates the rules and will get you a $25 fine).

Ran the car off the tow dolly, and I'm sure you guessed by now, the OD wouldn't engage. Later in the day, we took a drive, and it worked flawlessly for the remainder of the afternoon. That night, no OD again. Grrr...

I activated the switch and no clicks heard at the solenoid (though the relay clicked and the arrow illuminates).

I borrowed a jack and stands and in total stealth I raised the vehicle, and had my wife activate the OD switch. I had voltage AT the solenoid, and the potential at the valve body was ZERO, indicating a good ground. So, my valve was BAD after-all (actually better than a bad transmission).

So, while I would have liked to torn into mine as you did yours, I ended up borrowing a Dremel, and bought a mandrel and some small cut-off wheels and opened a path between the fluid passages, and after cleaning the valve well w/ brake cleaner, replaced the vale w/o the small O-Ring, and a tad of silicone gasket maker on the large one (since I didn't have access to a new one), and the OD is, of course, working perfectly, and I have no leaks (another HOA violation, of course; even washing your car results in an "unauthorized liquid discharge" fine).

The one strange thing is that the first time I had the valve off, not a DROP of trans fluid came out (despite the fact the OD had been working up until the day before removal), but this time a LOT came out. In any case, the OD now works, and we can drive the car on the Freeway.

The best part is that we didn't get fined by the HOA. Our son lives in another HOA 10min away, and the "Board" recently changed the "acceptable" colors for home in the subdivision, so he received a notice that he had until Oct 1st to re-paint his house in one of the new colors or be fined $100 per month until he presented bills for the new paint change. The new color closest to his present color is almost indistinguishable from his present color by MY eye at least, so I guess compared to that even a $25 fine for working on my car in our carport (a 3-sided garage w/ no door) would have been cheap, I guess. GOD, I hate HOAs! But I love the Volvo.

The HOA story reminds me of an episode of X-files. No wonder people go live off the grid.

No way would I say I told you so. More like join the club.

Thanks for returning with the story. I thoroughly enjoyed it outside of sympathy for your challenges. Won't soon forget it.
--
Art Benstein near Baltimore

I hate it when people forward bogus warnings...but this one is real, and it's important.

So please send this warning to everyone on your e-mail list:

If someone comes to your front door saying they are conducting a survey on deer ticks and asks you to take your clothes off and dance around with your arms up, DO NOT DO IT!!

IT IS A SCAM; they only want to see you naked.

I wish I'd gotten this yesterday. I feel so stupid now....

Man, you went the limit to try to repair yours!

The extra spaghetti over my wire crumbled, but the inner insulation was fine on mine. I just repaired wiring to my speedo pick-up sensor that crumbled to dust like yours, so I understand. My top boot was disintegrated, BTW. The shifter fork pin was a bear to get out as well. The car came from D.C. area so is not too bad corrosion-wise.

I forgot that older manuals used a solenoid activated as my old British cars did "Laycock de Normanville OD." I should have mentioned "Auto-Trans."

I am so far reasonably certain mine is fixed as it worked cold flawlessly on the bench, and since re-installation has worked perfectly so far in testing.

If nothing else, I went to school on R+R to cut the channel next time.

We're taking the car to an AZ condo to leave it, and I have no repair capability there, so I wanted it working before I left.

Fingers crossed...