Mtd lawn mower throwing belt off

[Sylvest]

Hi. I have a problem with a old mtd lawn mower. Everytime i move in reverse gear the belt trying to come off. What could be the problem? I have noticed the big pulley moving a little forward in the moment i go from forward to reverse mode, is this normal? Best regards from denmark

 

[ILENGINE]

The bolts or bolts for the transmission support bracket either on the front or front corner has come out or broken allowing the transmission to rock and rolling the belt off of the pulley. If you find that is the case also need to check the frame at the axle mounting points because the rocking of the transmission cracks the frame around the two mounting bolts on each side.

 

[Sylvest]

Okay. Thanks