clutch or gearbox issue? or could it be worse?

my 98 5th gen 24k miles had a huge crunch noise and rear lock up. when i parked up there was about a few inches of movement in the chain with clutch on or off. couldn't/wouldnt go into neutral either. engine runs fine.
I got it home and got the rear wheel off, and managed to get the chain moving by hand, then also when ignition was on and releasing the clutch gently the chain would move also. albeit the chain is amazingly loose now (i assume because of the lock up) sprockets and chain look to be in good order.
im not a mechanic and wouldn't be comfortable poking around any further than i have.
would anyone have an idea as to what may be the issue?
cheers
pete

 

no i haven't tried that. i'll check and post the results. although i don't think that would explain not being able to get neutral. an expensive fix is what I'm expecting . thanks for the reply

 

Sounds like the gearbox mate had same on his.

 

got a good look at the chain and sprockets today- no issues here.
going from here it will have to be checking the clutch and gearbox. has anyone any advice or useful links to show what to look out for? thanks

 

Crunch and a lockup is very unlikely to be the clutch unfortunately, almost certainly you've suffered a serious gearbox malfunction. My guess is that you've either broken a gear dog off a gear, or maybe a shift fork has snapped. Either way, you need to have a loose piece of metal lurking n the gearbox in order to cause a lockup. It might drop out and allow the gearbox to turn, but you'll still have a broken gearbox. If you pull the oil pan off the engine, you might be able to find the broken bit or see the damage, but a repair will require engine removal and splitting the cases.

 

thanks for the advice. any idea what would cause something like that to happen?