I just purchased a 1971 Case 580CK Backhoe. It has a working tach with 1100 hours showing. The story is that the seller's grandfather bought it new, and when grandpa died, it sat until now (several years at least) The machine starts and runs nice. The loader and hydraulics work, after I added about five gallons of fluid. The big problem is...It won't move either forward or reverse. The clutch pressure gauge on the dash shows good pressure until I move the shuttle to either forward or reverse, then drops significantly. Any recommendations on where to start would be appreciated. By the way, Not bad for 800 bucks!