Lawn Mower: Won't Maintain a Set Cutting Height

If your lawnmower won’t maintain a set cutting height it might have a worn or damaged wheel adjuster. The wheel adjusters are usually made of a thin, spring steel. They index to a quadrant that is attached to or milled into the mower deck. The quadrant has several notches in it so the mower blade can be set at the height you wish to cut your lawn. The wheel adjuster usually has a pin attached to it that locks into the notches on the quadrant. The adjuster is attached to the wheel bracket so when the adjuster is moved it moves the wheel up or down. Most wheel adjuster problems are the result of wear. The pin that locks into the quadrant will wear over time, causing its edges to round off. When this occurs it will tend to slip out of the quadrant, especially when the mower goes over a bump in the lawn. Sometimes the pin will even break off so the adjuster can no longer be set at all. A close visual inspection of the adjuster and quadrant should lead you to the offending part. Replacing a wheel adjuster is typically a pretty easy repair. You will start by removing the wheel from the lawnmower. The wheel will be secured by a nut or a bolt. Some models may have a hub cab over the fastener that will need to be removed first. With the wheel removed you will have access to the wheel bracket. There are many different methods the various manufacturers use to secure the wheel bracket. The next step is to remove the wheel bracket from the axle. If you are repairing the wheel adjuster on one of the drive wheels, you will often need to remove the drive gear first before you will be able to remove the wheel bracket and the adjuster. Make sure you pay close attention to the order that the various spacers, springs, and gears come off the axle so reassembly will go smoothly. On some mower models the wheel adjuster will be fastened directly to the wheel bracket. If so, you can now remove the adjuster from the bracket. On other models the two parts will slide off the axle separately. Once the old adjuster has been removed you can install the new one and reassemble the wheel bracket, drive gear assembly (if applicable), and the wheel.