OD Relay soldered, now UP arrow on dash is on

Are you sure you didn't accidently bridge two joints in the relay?

Not sure what the whirring sound would be, I doubt that's related to the relay.

(92 wagon)

Posted a similar problem a while back. Stuck in overdrive. Solenoid was totally shot and replaced. Relay checked and ok. No problem with up arrow light. So everything outside of transmission apparently working.

Last resort was power flush. Took to dealer, asked to watch beginning of fluid drain before flush. Saw fluid come out, about 3 quarts(?) It was still red, though not bright red as new. Saw no black gunk, metal bits, etc. Dealer suggested not doing power flush because 1) they "sometimes may break things" during flush on older car and 2) fluid was very much cleaner than we expected.

Replaced 3 old quarts with 3 new quarts. About 2 weeks later overdrive started to "unstick" at about 55 mph. Has now been unsticking more frequently and starting at about 40(?) mph.

Am going to change out 3 quarts transmission fluid every 5,000 miles along with engine oil from now on. May be overkill, but short money. Why is engine oil changed so frequently and not transmission fluid? Doesn't make sense on something with so many moving parts.

Both lubricate moving parts, but engine oil gets contaminated by combustion gases.

There's a LOT more dirt created in the engine from burning fuel, and the operating temperature of many parts is substantially higher. Changing the transmission fluid is a good idea, but every 30k-50k is more reasonable.

For your car the ATF should be flushed/replaced every 30,000 miles (Volvo recommendation).

All the best, Peter.

Agreed. I plan to change 3 quarts per service only. Fully flushing it out will depend on what my mechanic says about what may break as the dealer put it. My mechanic doesn't have the power flush machine. Have to go to a dealership for that, or god forbid, a national chain transmission shop.

If you just drain the pan about 2 quarts comes out. You can also replace all the fluid at one time (sort of a power flush) by hooking up a 1/2" clear hose to the top trans cooler line at the radiator, put the other end in a gallon container and run the engine about a minute at a time. stop the engine after about 2 quarts of fluid comes out. Top off and do it a few more times until the new fluid starts coming out. Takes about 9 quarts to do it this way. I did it on my 89 740T I bought used with 179K miles. The 2 quarts from the pan came out pretty clean but the rest from the flushing method was somewhat redish/brown and a bit murky. Shifted much smoother afterwards. HTH

Dave