This is for a friend's civic...

He noticed a grating noise while in reverse a few days ago, and when the gear cought, it jerked the car pretty hard. Yesterday, his girlfriend tried reverse, but it wouldn't catch at all - no more reverse. All the other gears drive fine and make no noise. Reverse light comes on when in reverse. I'm not familiar at all with auto trannies, much less Honda's. Any help would be appreciated.

If there's an easy fix, that would be great. Otherwise, he can pick up one from a salvage yard around here for 150-200 bucks, and I told him I'd help him swap it in. Can this be done with the engine still in the bay, or will we have to pull it as well (I can do mine in my driveway in one day...)? Hoping it doesn't come to that.

Thanks in advance.