5MT Popping out of 5th gear

[svanlare]

Help

I've been logging miles on the car now that it is street legal, and clearing various problems before I move back to finishing the body, doing liners and completing the interior. I figure it is easier to fix things while still relatively easy to pull a panel.

One persistent problem I have not been able to solve is the transmission keeps popping out of 5th gear while running down the freeway. It is 5MT with a stock 2.5 WRX motor and had 80K miles before I got them. I have a k-tuned shifter setup with the linkages running straight back to the transmission. It doesn't seem to happen when the car is cold, but once it happens after 5-10 minutes, it starts to happen frequently. So far when that starts to happen I have just driven in 4th from there and usually pull off the freeway and take surface streets. I have no idea if this was a problem before when the driveline was in a WRX as I got the parts stripped and delivered in a crate.

All I've done to attempt to fix the problem is adjust the shift linkages. That didn't seem make any difference.

The fluid reads high, but when I filled the transmission, I put the car on a slant (to make the transmission level), and then when the car is level the dipstick reads high. I am going to drain the transmission and fill again as the next easy step.

After that, I'm at a loss on what to check, and would love suggestions. Clearly synchros could be a the problem, but I assume the donor car would have been in the shop to repair if the problem was this obvious then, so I'm thinking it is far more likely that something I have done isn't right. But then I'm really hoping the fix is OUTSIDE the transmission so I don't end up having to get another one.

[Hindsight]

Had that happen on an Audi S4 I owned. Traded that POS in before even more stuff happened. It was definitely an internal issue like a bad synchro or chipped gear, etc.

I'm going to challenge you on your hypothesis that the donor car would have been in the shop to repair the problem if it was that obvious. Especially on older cars that young people frequently own, like VWs and Subarus, they tend to let things like this go forever, or for as long as they can because they don't have the money to fix it. The car is still driveable and the repair bill for that would have been many thousands of dollars.... could cost well over half what the car was worth.

[svanlare]

I can hope

[turbomacncheese]

Agreed. My dad's 4th wife (!) had a Datsun with the same problem. She just held the gear shift in place when she really needed fifth, and did her best to just drive in fourth gear because my dad said he'd trash the car before paying to fix it.