Riding Mower and Tractor: Not cutting evenly

If your riding lawn mower is making an uneven cut, start by checking the pattern of the uneven cut to help you figure out why. If the cut looks like slanted stair steps, inflate the tires to the manufacturer's recommendation and level the mower deck. If you see alternating stripes of taller and shorter turf, slow down while mowing—mowing too fast can cause those stripes. If slowing down doesn't fix the stripes, sharpen or replace the mower blades. Sharpening or replacing the mower blades is also the answer if grass tips look ragged or tattered instead of cleanly cut.

Blade vibration also causes an unevenly cut lawn. To eliminate vibration, replace unbalanced blades and worn mandrels. Check the blade belt, because a worn belt won't spin the blades correctly. Worn deck idler pulleys can also cause vibration, so replace any deck pulleys that don’t spin freely. Check the mower deck for damage and replace the deck if it’s bent. Finally, tune up the mower engine if it doesn't run smoothly when mowing.

These repairs may help solve your Riding Mower and Tractor problem:

Replace the riding mower mandrel assembly

Mandrel assembly

If a noise comes from the mower deck while the riding mower or lawn tractor is running, or if the mower isn't cutting evenly, you might need to replace the riding mower's mandrel assembly.

For manuals, repair guides, and specific part recommendations, enter your model number.

Level the mower deck on a riding mower

Mower deck

A tilted mower deck can cause uneven cuts. Park the lawn tractor on a flat surface and inflate all 4 tires evenly. Lower the deck to the cutting position and position the blades sideways. Measure the height of the cutting blade outer edges. Adjust the mower deck hangers to level the mower blades for an even cut.

For manuals, repair guides, and specific part recommendations, enter your model number.

Replace the riding mower mower blade

For manuals, repair guides, and specific part recommendations, enter your model number.

Replace the riding mower blade belt

Blade belt

The blade belt spins the blades to cut the grass. A worn or broken drive belt won’t spin the cutting blades so your mower won’t cut the grass. Examine the blade belt regularly and replace it if it’s worn or broken.

For manuals, repair guides, and specific part recommendations, enter your model number.

Tune up the riding mower engine

Fuel filter

The engine tune-up includes routine maintenance for a riding lawn mower or tractor. This tune-up includes replacing the engine oil, oil filter, air filter, fuel filter and spark plug. The tune-up also includes checking the ignition, carburetor, battery, throttle and choke controls, as well as cleaning the engine cooling fins.

For manuals, repair guides, and specific part recommendations, enter your model number.

Replace the mower deck on a riding mower

Mower deck

The mower deck houses the cutting blades, mandrel pulleys and blade drive belts. You may see uneven cutting if the mower deck gets damaged because the deck. Severe rust can corrode the deck, causing holes in the deck. Replace the mower deck if it’s damaged or there’s a lot of rust.

For manuals, repair guides, and specific part recommendations, enter your model number.

Replace the riding mower deck idler pulley

Deck idler pulley

You might need to replace riding mower deck idler pulley if a noise comes from the mower deck when the riding mower or tractor is running, if the belt is loose, or the belt comes off.

For manuals, repair guides, and specific part recommendations, enter your model number.