Manual transmissions

Have you tried to put it in another gear before shifting into reverse? Hit 2nd or 3rd before you try reverse and see if this lets you into reverse. Also does it grind any when you try to go into reverse? It sounds like you have synchronizer problems but don't take my word for gospel. I would also check my adjustment and make sure it is disengaging completely. If everything checks out OK I would have a good tranny mech. Check it out Hope this gives you something to work with. Good luck 8)