TTI sequential gearbox

I'm looking at buying a car V8 with a 4-speed TTI sequential gearbox (probably 5_7 years old), not engaging reverse or downshifting when the car is running, car is sitting a long time with engine out and in a few times, car will go in reverse when turned off, what do you think it would be Clutch, Release bearing or box issue, i know nothing about these boxes. thanks

It would seem to be clutch related. Try putting it in gear, depressing the clutch fully and, with the brakes applied, try cranking the engine.

If it cranks over, the clutch is releasing and you most likely need to look elsewhere. you can try releasing the clutch slightly, maybe 15-25mm off the floor while cranking to see if it has a very low clutch that may need adjustment, with some freeplay at the top.

If it DOESN'T crank, it suggests the clutch isn't releasing - if it's a hydraulic system, bleed it and retry, if a mechanical, check the adjustment and adjust if required and retry.

If those are good, see if you can use a torch to check the clutch fingers are moving - you'll need a helper to depress the clutch on command - if they are, then I expect the friction plate is stuck to either the flywheel or pressure plate, this is more of a problem where there is dampness or moisture in the air, as rust can form and stick the plate.

SOMETIMES, bumping the vehicle, in gear and holding the clutch down, can free up lightly stuck plated, otherwise you need to pull the engine or gearbox and strip the clutch assembly to clean it off or, in bad cases, resurface or replace parts.

It may be something else, but that's where my money would be.

Thank you, Ill try that....