Lawn Mower: Cuts Grass Unevenly

If your mower cuts the grass unevenly you might have a damaged mower deck. The mower deck is the central component of your lawnmower. The engine, transmission, wheel assemblies, and handle assembly all attach to the deck. The deck has guides and baffles underneath that guide the grass depending on if the mower is bagging or mulching. Damage to the deck can affect any of the assemblies that attach to it including the wheel assemblies. The wheel axles and adjusters attach to and are supported by the deck. There are several common problems that can cause the deck to make your mower cut the grass unevenly. The deck can be bent if it is repeatedly hit against solid objects such as a fence or tree trunk or if it is dropped out of a vehicle or off a ledge. This type of damage can also break or bend the reinforcement brackets for the wheel assemblies and axles. Rust can weaken the deck, eventually leading to flexing and bending of the deck. If the mower strikes a large object on the lawn, such as a rock or chunk of wood, the blade can propel it with enough for to bend the deck or the support brackets underneath. Any of these problems can cause the wheel assemblies to become out of alignment to the deck which can cause the mower to cut unevenly. The steps to replace a mower deck vary greatly by brand and model. In any case it is not a simple repair and will require some previous experience and a decent set of tools. If you are a novice do-it-yourselfer this might be a repair you want to leave to a pro. If you have the tools and are up for the challenge you can save yourself a lot of money. The repair consists of stripping all of the mowers components off of the deck. This includes the engine, the transmission, the handle assembly, the wheel assemblies, and any other shrouds or covers. While breaking the mower down make sure you keep track of the fasteners and make notes of things like cable routing and the order of spacers, etc. so the reassembly will go smoothly.

If your lawnmower is cutting the grass unevenly you will want to inspect the wheel adjusters. The wheel adjusters allow you to raise or lower the deck height to adjust the length the grass is cut to. There is a wheel adjuster on each of the mower’s wheels. The adjusters attach to the wheel brackets and pivot the brackets up or down. The adjusters index into slots on a separate bracket, or the deck, which hold the adjuster at the specified height. After years of use the adjuster or the indexing bracket can begin to wear. This can cause the adjuster to slip out to the bracket and the deck drop to a lower height. One corner of the mower will now be lower than the others and the mower will cut the lawn unevenly, often leaving a ridge in the lawn where your rows overlap. The adjuster can also be bent so it won’t hold firmly against the indexing bracket, causing the same issue. Replacing a wheel adjuster is an easy repair, usually requiring only a few basic tools. Start by removing the wheel from the wheel bracket. Depending on the design of your mower you might now need to also remove the wheel bracket. Now you can remove the wheel adjuster from the mower. Install the new wheel adjuster and reassemble the wheel assembly.