the PTO drive belt on 20hp Z-Force 44 keeps jumping off the the idler pulley resulting in the idler arm assembly (top) bending down so that the idler pulley wears on the flat pulley of the lower idler assembly. Any clues please?
Make: Cub cadet
Model: 20hp Z-force 44
Straightening bent idler arm assembly (top)
If the belt is continually jumping off of the pulley then the belt may be worn and need to be replaced. I would also inspect the alignment of the belt to the other pulleys as well. Check all of the pulleys for excessive movement on the shafts and bolts they are mounted to also.
have tried a new belt - pulleys and alignment ok - mower has only done 100hrs. could it be the spring from the spring tension rod assmbly to the idler arm assembly is too weak? Can you please advise what tension should be on the spring when the idler pulley is engaging with the PTO belt?
They do not list a published tension spec. A weak spring is possible, but to confirm it you would just have to replace it.