Hi
I've got a F reg mi16 I tried to reverse it out my driveway and relised I couldn't select reverse! Its got the early pull up gearbox and each time I think I got reverse its actually in first. Is it a problem with the whole gearbox or just the pull up cable? I bought the car recently and have only driven it up and down my street but it seemed to work fine. Ive got an H reg mi16 that I'm breaking, how hard would it be to transfer that gearbox (it has the later non pull up system). I know very little about gearbox's but have plenty of time on my hands.

Any ideas?

First thing to do would be to check that the cable hasn't broken. If you try and select reverse and get someone to look under the bonnet to see if anything is moving gearbox end

I've removed the gear gator and the cable is still attached and seems to be quite tight but ill have a look tomarrow under the engine like you said.
cheers