OT: Legacy transmission
 

Here's the thing - my wife's Legacy is a Brighton, so it doesn't have a tach. That makes diagnosing this problem I'm having a little more difficult. :p

I'm pretty sure it's hunting around for gears. It seems to happen while cruising around town. Sometimes it happens while accelerating, sometimes while just maintaining speed. I'm pretty sure it's not slipping, because when I feel it hunt around, I goose the throttle and it's definitely in gear. The engine doesn't rev freely. It also shifts perfectly otherwise. I've had slipping Subaru transmissions, and this isn't one.

I don't have any warning lights coming up. My OBD-II scanner is loaned out, but the transmission light isn't flashing on startup like it has before when there's an electrical problem.

I'm going to add a little ATF just in case it is slipping. It's full, but the aftermarket filter I put in there has a shorter pickup and the pan has to be a little overfilled for it to maintain pressure.

My theory for right now is the selector switch. I think it needs to be adjusted or even replaced. I can't reproduce it reliably, but as soon as I suspected the selector I pulled gently back on it and 'the problem' happened.

Anyway, I'm open to other theories or ideas.

Sounds exactly like my problem with the 2-3 shift.....feels like its hunting but i know its definitley in gear. Pretty weird.

Gid'ay Paul, If it was the selector switch that was making it shift gears, the gear position indercator on the dash would show the changes, as they are driven by the shifter.
Could be the Throttle position sensor, worn,loose, ect.

Harvey. ;)

Paul? :)

Harvey, the Brighton trim level was as stripped down as Subaru ever sold the Legacy here in the US. No tach, no power anything, no cigarette lighter, even.

So it doesn't have a dash indicator for the gear selector.

It could definitely be the TPS. The car has 164k miles on it and, as far as I know, the TPS is original. Wouldn't a bad TPS throw a code, or would the sensor have to be totally dead for the code to come up?

My wife just got back from some errands. I asked her, while she was out, to try driving the car with the selector in '3' instead of 'D.' She says the problem was more frequent and worse. That was what I suspected might happen, and makes me lean even more towards the selector switch.

Thanks for the diagnosis help, Harvey. I don't think the problem is terminal, but it is annoying.

Sorry Nick, :eek: early morning here :confused:
Well the selector switch has an earth wire, that could be loose.

Worse in third, sounds like the dropping resistor. Sort of symtoms that it gives. The TPS may just have a bad spot on it, so there won't be a code, it just thinks you have moved the foot on the throttle.
Harvey. ;)

Sorry Nick, :eek: early morning here :confused:
Well the selector switch has an earth wire, that could be loose.

Worse in third, sounds like the dropping resistor. Sort of symtoms that it gives. The TPS may just have a bad spot on it, so there won't be a code, it just thinks you have moved the foot on the throttle.
Harvey. ;)

I suppose the best way to check that would be with a meter. I wonder what the range is supposed to be. Although, I suppose I could test your 'dead spot' theory even without knowing the range.

Could I swap in the TPS from my SVX, which I've barely driven this summer anyway, to test it? :D