The kids were driving my '91 240 on a trip this past weekend and after 3-4 hours on the road they stopped. When they got back on the highway they said that it had problems shifting into 4th gear. They fiddled around speeding up/slowing down and finally got it to shift and didn't have any problems after that.

Now this has the automatic and the overdrive arrow was not showing on the dash so I doubt that it is a problem with the relay. I am thinking perhaps that the overdrive solenoid may be going bad or perhaps the transmission is starting to go. The car has 196k miles on it.

Is it time to start looking for a new trans or is it most likely the overdrive solenoid?

 

I would agree with it being the overdrive solenoid, but I would also flush the transmission fluid.

 

bubba's right.
Solenoid sounds like the issue, But i would check the wiring under the car going to it first before i bought a new one. Could be that its cracked and just isnt getting power.

Also IPD sells there Overdrive solenoid bypass if you just want to solve all issues with an electronic overdrive once and for all. (my car is litteraly in the shop as we speak getting one put on it.)

 

Well, it happened only once so it isn't a hard failure yet. I think a trans flush is in order so I will tackle that when I get a chance (currently my other 240 is in the garage awaiting a timing belt).

I was thinking about this some more - could this be a sticky kickdown cable? It was really cold the night this happened (around zero F)

 

I've had a problem like this when the trans got hot and blew fluid out of teh breather.
If it is a one off, I'd forget about it.
Kickdown won't cause it, OD is primarily controlled by governor and the solenoid.

Regards, Andrew.