I have an issue with reverse.

Even from a standing start, the rev gear crunches (and doesn't sound too good)

it only happens occaisonally but it causes concern..

would tightning/loosening the clutch cable relieve this??

car model : Seicento Sporting 1.1
year : 2003

I dont want to have to fork out for a gear box.. Car cost enough as it is!

Adjusting clutch cable would be a good start.