Gearbox Damage - only 3rd/4th work.

[Kaison]

Okay, I have a little issue with my C20XE which I believe has an F20.
I was driving through a tunnel with the windows open, as you do. Changed down to 3rd at 50mph and accelerated, went into 4th and continued to accelerate with my foot down, went to change to 5th and missed, hitting 3rd. - This resulted in me instantly reapplying the clutch and trying for 5th again. Still wouldn't work, tried a few times and noticed a vagueness in the lever. It wouldn't sit in the middle when in neutral, would stay where you left it. There was no side to side resistance, so settled for 4th and continued till I was off the dual carriage-way. As I slowed, tried to get 2nd and had no luck, thought I had gone into 4th (which I had) but assumed it was an accident. - 2nd and 4th are close and it has happened before. Tried again and it was bogging now. Knowing it may have an issue I just used the clutch to keep the revs high enough for the engine not to struggle and proceeded till I was in a safe location to jack the car up. Looking up at the linkage, it seems something has broken on the linkage, couldn't see any fluid leak so hoping the gearbox isn't cracked or damaged. When I lowered the car onto it's wheels and attempted to reverse, I noticed even though I was raising the gear-stick and going into the genuine reverse position, I was still hitting 3rd.

Am I right in assuming it's just the linkage that's damaged as 3rd and 4th still work fine?

[P71GEF]

Probably the reaction rod on the linkage has worn and popped off. You can get metal ones off eBay, which I've fitted to a few corsa c linkages an they've never came back off. You should be able to pop it back on just now but it will keep popping off regularly