Toro Timecutter 5060. mdl 74641 about 8 yrs old SN314000001. Was cutting grass and it just died. Couldn't get it started so I pushed in the bypass's and turned on the key and towed it backwards about 100 ft to where I could work on it. Got it running and now the R transaxle is locked up , the wheel won't turn in either direction. The L transaxle works fine. When it's running an putting the R transaxle lever in forward or reverse it just makes a sound like maybe the hydro fluid is coming up to some kine of block. With the motor running if I engage and disengage the L transaxle bypass lever it moves freely. If I do the same with the R transaxle bypass you can hear gears grinding but it has no effect on the Locked wheel. The electric brake seems to be working properly. Any ideas?