My Volvo 240 wagon needs the overdrive solenoid replaced. I have a new part. Is this something I should try to trackle myself or should I let the mechanic do it? I've heard its pretty straight forward. Thanks!!

I am currently doing the same job.
1. Check #12 fuse for 12 volts.
2. Take out the glove compartment, approx. 7 philips screws, and locate orange relay to the left. Hold it while engaging the over drive (actually underdrive) switch on the shifting lever. You should feel the relay click while engaging and disenganging the swithch. Take out the relay and check for continuity between post 15 and post 86. Check for incoming 12 volts to #15.
3. Get under the car. Make sure it is well supported and safe. The selenoid is on one side of the tranny, but the wire to it goes up and over the tranny to a connector almost directly opposite of the selenoid. Make sure you have the ignition on, the overdive switch off, and check for 12 volts at this connector. This is where I was, when I knew I had to take out the selenoid.
4. Disengage the shifter arm at the tranny to gain access to the metal clip where the wire goes through and take off that clip, too.
5. Now comes the hard part, getting the selenoid off the tranny. You will need to buy, make or find a 12 mm wrench bent in the shape of an "L". There are two bolts which must come off, and all I can say is good luck.

Are you absolutely positive the solenoid is bad? They seldom fail, but there are simpler electrical problems that will prevent the solenoid from working.

Or it may be clogged with deposits from old burnt fluid, and might come back after a fluid flush (directions in the 700/900 FAQ -- same as 200 tran.).

That's a pretty pricey part to change without being 100% sure, and it's easy to test electrically. In any case, it would help to know your car's YEAR, and whether the transmission is Auto or Manual.

My guess is Auto, but guessing wastes everyone's time and leads to frustration and mistakes.
--
Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.

See the 700/900 FAQ under "features" above for tips: you have the same tranny. It does require jacking the tranny and removing the cross member.

I changed one a year ago just by getting the car up on stands. It's very dirty in the area where the od solenoid lives on drivers side of trans. I had some pb blaster and a short stubby box end wrench. Two bolts - came out easy. The nifty part is pulling it out without getting dirt in the solenoid hole and watching the little rubber seal - plus you have to disconnect the wire to the solenoid which was not difficult if I remember.

Took less than an hour, but I got lucky!

Bob Weber
Hamilton, Ohio 45013
60 Volvos since 1978