My corsa (c20xe+f20) gave me a bit of bother at the weekend. I was reversing around a corner and came out of reverse a bit too quickly, this resulted in the box getting jammed in reverse!
I popped off the selector and eventually got it out of fifth, put back on selector and set up linkage, and next thing is i have lost reverse, 1st and 2nd. Leaving me with only 3rd, 4th and 5th.
I took off the selector and tried moving the forks manually but they were jammed solid, with only very slight movement from side to side.
I removed the end plate and took out the cluster fearing the worst....

Turned out that the little magnet had split in 2 and fell out of place, sticking itself to one of the selectors, locking it in place!

If only all problems were as cheap to fix as this lmao