1988 volvo,740 automatic 178,000 overdrive trans

[joe curtin]

i had this volvo for 2 yrs now its a great car but it seems to get stuck in 3rd and doesnt shift in to overdrive.the arrow stays on.i push the button on the shifter but it doesnt seem to work. it shifts great no problem just overdrive,and its hell on gas when i have to go on the highway cuz the r's go past 3,000 over 55mph. its always done it on and off,but now its stuck maybe for good.

[JRL]

You're in the wrong forum but anyhow these are known to fail.
I do not know the remedy, ask in the proper forum

[MadeInJapan]

Sending this thread to the RWD section of MVS. I hope you find some answers there. Btw, my 240 is doing this now. I know that it's either the overdrive relay or the solenoid- but probably the solenoid. Evidently you can take it out and dremel a groove in it and you never have to worry about the button on the gear shift again- it will just automatically shift when the rpm's get up high enough. How to do this, etc. will be forthcoming (hopefully) from members here. I plan on doing this when I get some time and the know-how.
MIJ

[billofdurham]

Four things can go wrong, barring major mechanical failure.
1. Faulty switch.
2. Overdrive relay.
3. Overdrive solenoid.
4. Fluid overdue for flush and replacement.

1. To test the switch prise it out of the lever, disconnect the wires and test across the two contacts for continuity with an ohmmeter. You need to press the switch to test it as you won't know if it is on or off.

2. To test the relay is about impossible unless you have a known good one to put in its place. However, sometimes a good hard flick with your finger can shock a dodgy relay into life. If it works change the relay.

3. To test the solenoid:

http://img155.imageshack.us/my.php?imag ... oidfs4.jpg

4. Flush and replace.

I have not heard of MIJ's solution and would need to do more research before commenting.

Bill.