Anyone know why my box won't hold 5th? It just jumps out straight away!

A box specialist suggested undoing the plate on the right hand side (a long narrow plate held on by 2 bolts) and moving the plate then trying that. Wadya think?
Paul

does it jump out when you put it into fifth or when you put any power/torque through the gear?

the girlfriends beemer does this is 1st + 2nd. i recon its either a dodgy synchromesh ring/hub or bent selector fork. are all the other gears ok?

Ned.

It doesn't feel like it goes in properly therefore is probably out before even the power comes on.
Tonite I've taken off the plate on the drivers side and it then goes in ok and seems to stay in. the plate doesn't look damaged at all.

Any ideas?
Paul

was it ok before you put it in the car?could be the prop is too tight,ie pushing on the mainshaft,if not probly the baulk ring has broken

Dunno if it was OK as it was given to me as a recon.

I have been wondering if the plate that has a fork on the inside of it obviously holds something (a collar?) but this something can be seen moving forwards and backwards when selecting fifth (with the plate off obviously.

Maybe this collar thing should hold its position via the fork but its corroded on the shaft that goes through it hence moving forwards and backwards when selecting 5th?

Was thinking if this is the case trying to free it up under force (a screwdriver?!) and if I can adding some molyslip for future protection.

Does this sound a bit brutal?!?