To properly operate a 38- or 42-inch riding lawn mower on a Craftsman tractor, Sears recommends using a No. 144959 V-belt. The belt, whose identifying number often appears on its inside edge, controls the spinning mowing blades. If the belt breaks or becomes worn and ineffective, a lawn-tractor service professional or, with proper tools and preparation, the owner of the machine can replace the belt.
A 144959 V-belt has only one size, and spans a half-inch in width and 95.5 inches in circular length. In addition to being suitable for 38- and 42-inch Craftsman mowers, this part fits some 46- and 50-inch wide Husqvarna model mowers sold through Sears. Consumers can purchase the belt at a Sears store or order it from websites that sell lawn-mowing equipment.
On most models, the mowing deck has either two or three spinning blades. Powered by a pulley attached to the engine, the 144959 V-belt winds through a series of blade pulleys on the mower deck to spin the blades. Over time, this belt can become worn and may slip in the pulleys, affecting the output and performance of the mower.
If you decide to change the belt yourself, Sears recommends first placing the tractor on a flat surface and locking the wheels in place. Sears also suggests wearing sturdy gloves during the repair work, to avoid injury from the sharp blades.
Although you can remove the mowing deck from the tractor to gain easier access to the belt and pulley system, you also can work on the deck by simply moving it to its lowest level via the deck adjustment lever located on the right side of the tractor seat.