Scag 36in Walk Behind Belt Driven

[MKR Lawn Care, LLC]

My Scag 36 in Walk behind right side belt comes off the wheel occasionally. I have to stop the machine and guide it back on the rails of wheel. Trying to troubleshoot the problem and can't figure it out.

[nick11380]

I have that problem sometimes with my 48" Exmark. With mine there is a bolt that loosens up on the pully that moves when you sqeeze the brakes. When I tighten the bolt that fixes the problem until the bold loosens up again which doesn't seem to take very long. Maybe I should change the nut.

[DavidNJ]

Or use Loctite, a nyloc nut, or even a lock washer. However, a lock washer isn't good in high vibration environments.

If replacing the nut I'd also replace the bolt. If the bold was changed to one of inadequate spec, or the bold was defective, the threads may not be holding adequate tension. Airplanes use aircraft bolts rather than SAE or metric bolts. While the yield ratings may even be lower, the big difference is aircraft bolts have a specified quality control process. With Grade 8 and Grade 5, bad ones can slip through.

[GeeVee]

Wheel bearing play, belt worn, pulley worn, all of the above.

Belt drives can go two belts before the pulley sheave needs changed out too. Sometimes new belts wear prematurely because ownerts think the pulley lasts forever. It does not.

GV