I'll move this thread out of the D40 550 Engine & Gearbox area into the D40 Drive Train area.
As for why it's slipping out - it could be a problem with the selector in the box, what happens if you hold the gear lever in 5th gear position maintaining a little pressure on it? Does it then slip out?
We've seen this before in the UK after the clutch had been replaced. It is something to do with the alignment of the box/bellhousing either in relation to the engine or on the mounts.
Ask the garage that fitted the clutch and flywheel to check their work.
Good luck
Enter your email address to join: