The drive belt on a Yard-Man 42-inch tractor should be replaced as soon as it shows signs of wear or malfunctions during normal operation. Typical signs of belt wear are excessive stretching, visible cracks on the surface, a shiny "burnt" appearance or tractor slippage while in motion. It is a good idea to be familiar with the belt replacement procedures in order to save the substantial cost of an annual service call by your local dealer. Not only is belt replacement easy, but it will also allow you to spot any other needed maintenance items before they turn into large expensive repairs.
Park the tractor on a flat, level surface. Fully depress the clutch lever and firmly set the parking brake. Raise the hood to reveal the engine. Disconnect the spark plug wire from the spark plug to prevent the engine from starting accidentally. The spark plug wire is the thick black wire leading to the center of the top of the engine. The spark plug is covered with a rubber cap. Pull this rubber cap free to disconnect the spark plug wire from the spark plug. Lay it to one side of the engine.
Place the lift engagement lever in the disengaged position by pulling it towards you (while seated on the tractor) so that the drive belt has adequate slack. Crawl beneath the tractor as best you can and remove the two belt keeper pins; they are attached to the engine pulley belt guard, and are positioned so that the belt cannot come free from the pulley.
Pull the deck belt free from the engine pulley. While seated on the tractor, push the lift engagement lever away from you. Unhook the idler pulley spring attached to the trans axle bracket located inside the left rear wheel well using a large slotted screwdriver.
Remove the cotter pins holding the six deck links in place. Remove the six washers that provide spacing for the deck links. Disconnect the small stabilization plate from the stabilizer rod assembly by removing the hairpin clips and flat washers. Slide the rod free.
Disengage the lift engagement lever by pulling it towards you. Pull the mower from beneath the tractor so that you now have room to replace the drive belt. Crawl beneath the tractor and remove the three self-tapping screws from the transmission cooling fan. Remove the fan.
Remove the four self-tapping sheet metal screws that secure the belt keeper assembly to the frame. Remove the entire belt keeper assembly and set it aside. Remove the drive belt by rolling the belt off the top of the engine pulley and onto the pulley hub. Remove the belt from the transmission pulley in the same manner. The belt should now be free.
Remove the old drive belt. Install a new drive belt and reassemble the components following the removal steps in reverse order. Be sure all screws are installed tightly, and that all cotter pins are secure.