Hello. I was given a wonderful lawnmower last year, and it worked perfectly until last week, when the drive belt snapped—it actually fell apart completely. After two hours of work, I finally managed to install the new belt; I also noticed that a small spring near the transmission pulley had come loose, so I put it back in place.

When I started the mower, I noticed that engaging the drive lever required very little effort (likely because that spring had been disconnected earlier), so I loosened the cable tension. I mowed for about 10 minutes before the belt slipped off. I put the belt back on and tightened it again using the adjustment mechanism. I managed to finish mowing the front yard, then moved to the back and finished the perimeter before the belt slipped off again.

At this point, I really don't know what to do next. Could the problem be the spring? I’ve come across conflicting information regarding the belt length—33 inches versus 34 inches—but my local dealer insisted that this was the exact belt I needed.

If the belt slips off every 10 minutes, the issue is almost certainly insufficient tension or the wrong size. A stretched spring fails to provide the necessary tension and a difference of even one inch is critical for the drive system. Check the belt's OEM number in the catalog, select the exact original equivalent and order the correct part from UDC Parts. Once installed, proper cable tension will be restored and the slipping will stop immediately.