I have a Sears Craftsman LT 3000 Lawn Mower (model # 917 276813) and while I was mowing it just quit moving. I tried different forward gears and even reverse but nothing. The motor is still running and the blade still engages. I could feel the tension on the clutch change when the mower stopped moving. Any suggestions of what has come loose? Thank you.

Having read some of your other posts I think Sears gave you a lemon. Check the belt between the engine and the tansaxle in the back, it may have broken or jumped off the pulley