i had a shift linkage problem. i replaced a plastic cup that holds crossrod in place. before i replaced the part, it was hard to get in gear, but it pulled fine. after i replaced the part, it will go in gear, but will not pull. i jacked it up off the ground, put in gear, and the axle turns, but you can stop it with your hand. no pulling power. does this mower have a hydrostat transmission. cant figure out why it would quit pulling after a minor repair. thanks