The essential drive belt on the classic John Deere 100 lawn tractor wears down as time goes by simply due to normal operation. One sure symptom the drive belt has become incapacitated is noticing the grass in the patch you just mowed isn’t at all shorter than it had been. There is a simple explanation for this: The drive belt keeps mower blades spinning. Replacing the broken belt is not complicated, and you should be able to do the job yourself in about 30 minutes.
Park your John Deere100 tractor on flat ground. Remove the ignition key and disconnect the spark plug.
Grasp the long, thin deck lever situated on the right fender. Press the release button and push the lever forward until the deck arrives at the bottom level. Unscrew the hex bolts holding the belt guard in place, using an adjustable wrench. Pull the belt guard free from the center of the deck.
Scoot under the mower and yank the defunct drive belt from the engine pulley. Continue prying the belt until it is away from the stationary idler pulley. Peel the final piece of the old belt off the clutch idler pulley. The pair of idler pulleys are found closely adjoining the engine pulley.
Affix the new Deere belt along the grooves lining the clutch idler pulley. Grasp the pulley and turn it half a rotation. Attach the next portion of the new belt to the grooves along the stationary idler pulley. Fit the final section of the new belt around the engine pulley. Restore the belt guard.
Grip the Deere 100 deck lever and pull it backward until it is positioned at your preferred height. Start your Deere riding mower and test the mowing operations.