The part(s) or condition(s) listed below for the symptom Lawn mower not self propelling are ordered from most likely to least likely to occur. Check or test each item, starting with the items at the top of the page.
The V-belt rotates the drive pulleys to drive the lawn mower wheels. If the V-belt is worn out or broken, the lawn mower wheels won’t turn. Inspect the V-belt for damage. If the V-belt is defective, replace it.
The drive pulley connects to the engine crankshaft. If the drive pulley is worn out or broken, the transmission won’t be able to engage the wheel assembly. Inspect the drive pulley for damage. If the drive pulley is defective, replace it.
The wheel assembly has a set of gears which engage with the transmission drive gear. If the gears are worn out, the transmission won’t be able to engage the wheel assembly. If the gears are worn out, replace the wheel assembly.
The transmission is powered by the drive belt, and the drive belt connects to the engine crankshaft. When the drive belt powers the transmission, the lawn mower wheels turn. To determine if the transmission is defective, observe the transmission while the lawn mower is running. If the transmission pulley is spinning, but the lawn mower wheels don’t turn, this indicates that the transmission is defective. The transmission is not repairable—if the transmission is defective, you must replace it.
The transmission is powered by the drive belt, and the drive belt connects to the engine crankshaft. When the drive belt powers the transmission, the lawn mower wheels turn. To determine if the transmission is defective, check the transmission while the lawn mower is running. If the transmission pulley is spinning, but the lawn mower wheels don’t turn, this indicates that the transmission is defective. The transmission is not repairable—if the transmission is defective, you must replace it.
The traction control cable might be broken or misadjusted. Check the traction control cable to determine if it moves freely. If the control cable does not move freely, try squirting a small amount of oil into the end of the cable to lubricate it. If lubricating the traction control cable is not effective, replace it.