1996 Legacy Outback Wagon with 220k miles has new behavior I need help understanding. It appears transmission related.

 

Two days ago, I started down a level highway and transmission shifted normally until about 60 mph when I noticed that it failed to make the final shift to the highest gear. Engine hit about 4000 rpm and then I backed down. Tried to make a couple runs at it and it exhibited the same behavior. I pulled over, turned off the ignition, restarted, and the car drove fine.

 

Tonight, I was stopped at a stoplight (in town) and when I pulled away on the green, the same behavior repeated, but this time in 1st gear. Did not want to shift to 2nd gear. Again, I pulled over, turned off the ignition, restarted, and then the transmission worked fine.

 

Has anyone experienced the same? What did you determine cause/remedy to be?

 

I've had the car since about 168k and am unsure as to ATF change history. I know that I have not changed ATF since I have owned and that would be a good place to start. However, I'm wonderingf if this may be more of an electronic issue due to the way it presents.

 

Any advice/assistance would be greatly appreciated!

Are you experiencing any other issues?

 

Like you suggested, I'd start with the transmission fluid. You may have a solenoid that is sticking. New fluid should help.

Have you ever had a warning light come on that reads something like " ATF fluid hot?" That happened on my 91 Subie wagon. After that, the car never again shifted into high gear. So a word of warning, pull over quick, and shut down the motor, if that warning light comes on.

Thanks for the initial thoughts. No other issues with the vehicle. In fact other than these two isolated incidents, the transmission works smoothly and fuel mileage (MPG) remains consistent.

 

If the solenoid were sticking in some way, is that a serviceable item without pulling the AT?

Most of the time you can replace shift solenoids without removing the transmission.

 

Due to the intermittent occurance of the problem, I would suspect a possible issue with the TCM, but starting with a fluid change can only help.