is this a clutch problem?
Grinding when choosing reverse can generally be attributed to one of a few things. If the hydraulics are not passing fluid as effeciently as they should then you may be looking at an issue of reduced bearing actuation and thus limited clutch release when the pedal is depressed. Slippage on the other hand would be an issue of the bearing riding the diaphragm fingers as a result of overactuation if it was hydraulic...it is important to note that these issues are not generally found on the same car. I would first check the hydraulic fluid...is it discolored? Is it chunky in appearance (this evideces a breakdown of of material within the bearings or lines).
Let me know what you find and I will be happy to assist you further. Thanks!

