Hi everyone, I am new to the site, and have tried a search but am looking for a little more help. I have a1989 740t that has been having OD problems. At first I found and replaced the relay behind the glove box and the problem went away for a little while. Now I am looking to replace the solenoid but would like to know if it is something I can do without tearing down the whole transmission? It looks like just some bolts on the outside, and put in the new one.... Any tips?

 

Have you checked for loose wires on the overdrive switch, shifter and under the car? I have had to replace and/or re-solder the connections on several in the past. Especially the connections under the car, they get covered in oil and grime and often short out. In the Hynes manual there is a section on removing and testing the solenoid. Don't be fooled, it is difficult to get to and there is not much room for tools, hands etc. in there. That is why I check all of the wires and the switch first. It could also be that a short in the OD system is causing the relay to blow up. I don't think there is a way to test the relay, unless you have another Volvo or a friend with one. Check the wires, check the relay (if possible) remove and test the solenoid, would be my advice. [&:]

 

I am sure that I am about to make plenty of folks shudder, but I ran a wire directly from the solenoid to one of the tabs on my low beam headlight. If you always leave your headlights on when driving, you will always have forth gear.
Be sure and get the right tab because if you don't, when you switch to high beams, the trans downshifts to third until you switch back to low beams. Two out of three tabs will cause a downshift. You need to find the one that doesn't. Of course, you could always pull the plate on the trans that the solenoid wire comes out of and grind a channel between the two holes, permatex the thing and the place where it goes(after you clean it extremely well, that is) put it back on and if there are no leaks, the problem is solved foreve! Now those folks are quaking! This is not a "true" fix according to the "real" mechanics, but if you want to save time "AND" money, htese are what I suggest.

John.

 

You don't have to remove the solenoid to check to see if it functioning. Run a wire from the battery wire to the solenoid. If the solenoid is working, when you touch the hot wire to the solenoid wire you should hear a very distinct "CLICK" of the plunger moving out to allow for fluid flow.

John.

 

Thanks for the response, I have been trying to get home (I work on a ship) and will try when I do get home for Christmas.
I will let you know what I find.