How To Repair Lawn Tractor Blades That Do Not Spin

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  • Rated as REALLY EASY
  • 4 step by step videos

Deck Belt

If your mower blades will not turn after the blade controls have been engaged, your deck belt may be broken. The deck is located directly under the operators seat. This belt spins the mowers blades and runs through a pulley system of idlers. The exact configuration of the deck belt will depend on your model of mower. To inspect the deck belt, position the mower on a flat surface and lower the deck to its lowest possible setting. Clean out any debris or grass that may have built up above the mower deck, and remove any guards or covers that protect the deck belt system. Once the belt can be accessed, inspect it for any damage or wear. If the belt has snapped, it will need to be replaced.

Deck Belt Engine

If you have inspected the deck belt on your mower and found no issues, but the blades on your mower still will not spin, next check the engine to deck belt. This belt receives the energy created by the spinning motion of the crankshaft, and transfers it to power the deck belt system. Once you have removed the appropriate covers, inspect all belts for damage or wear. The engine to deck belt will run from the mowers engine, and connect to a pulley in the deck belt system. Any broken belts will need to be replaced. These belt systems also can get jammed with debris and grass, so be sure to clear our any blockages or debris that may stop the belts from rotating freely.

Blade Clutch

Some mowers are equipped with a blade clutch. This clutch stops the mower blades from spinning while the engine is running until the operator engages the controls. The clutch is located under the engine, attached to the crankshaft. The crankshaft will run into the centre of the clutch, and a belt will be attached to the clutch to allow it to power the blades once it begins to rotate. The clutch can wear over time and eventually require replacing or adjustments to bring it back into proper working order. To diagnose a broken clutch, the mower will have to be disassembled, and the clutch removed for closer inspection. If the clutch has any broken components or will no longer rotate, it will need to be replaced. Refer to your owners manual for the proper replacement part number should a new clutch be required.

Safety Switch

A bad safety switch can also stop the mower blades from rotating. Most lawn tractors are equipped with one or most safety switches designed to stop the blades from rotating if any of the switches are tripped. The most common locations for safety switches are; attached to the brake or clutch, on the operator’s seat, and on top of the transmission. All of these switches stop the blades from rotating by disabling the clutch if there is no weight on the seat, if the brake is engaged, or if the mower is put into Neutral or Reverse. If your mower blades will not rotate and you have ruled out all other causes, inspect the electrical connections in the safety switches to ensure they are not being tripped unnecessarily. Never disable these switches, as they are installed to keep the operator and anyone near the unit safe while it is in operation.

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