Small Engine Troubleshooting Problems? Ask a Mechanic Now.
Welcome to JUST ANSWER small engines, let me try to help you !! I don't know it all, but maybe together we can get you a satisfactory answer!
Is the drive belt from engine to transmission tight? Have you had either of the rear wheels off?
With both wheels off the ground, and you turn one wheel manually, does the other turn in opposite direction?
Did you do the turn one wheel , to see if the other wheels turns in opposite direction? If not, you have rear end problem or broken axle.
Yes, differential is ok, or wheels would t turn in opposite direction. . That only leaves the hydraulic unit.