Gearbox problem stuck in 3rd gear, synchro collapsed?

Hello all,

So i was driving my Series 3 109 petrol yesterday and i change into 3rd and to my prevail could not get it back out.

So when i limped it home i got it on the drive removed the floor panels and tried to determine where the problem is. Checked normal places, blockages on the selectors etc. No luck.

So i belive the problem is that the synchro has collapsed and now i need to rebuild the gearbox.

Can you offer any advice on this? how to do it? what to avoid etc? is it worth getting a replacement?

Please help if you can or offer any alternative info that could help

If your selector rods are clear I would take the top of the box to check the forks, if it is still stuck in gear take the box out and remove the bell housing. You can then pull the 3rd 4th syncro out and inspect it. It is all straight forward spannering once you have the floor out.

Is the mainshaft nut tight?

samc88 said:

Is the mainshaft nut tight?

Click to expand...

that's where i'd be looking before removing anything other than the rear support bearing/cover

Also, does it have an overdrive. I had bother with it jumping out of 2nd and being a bit tight on third, after slackening off and retightening the overdrive it was cured. Must have been a bit off centre...