April 19, 2023

Riding Mowers & Tractors: Why does my riding mower deck vibrate?

If the mower vibrates when you engage the cutting blades, there might be a problem with the blade drive system. Deck vibration can be caused by an unbalanced blade, worn pulley or mandrel, bad blade belt or debris caught inside a pulley.

Loose nuts or bolts on the pulleys, mandrels or blades can also cause vibration. Remove the mower deck and re-tighten all fasteners.

Check for wear on pulleys, mandrels and blades. Replace any worn or damaged components.

THESE REPAIRS MAY HELP SOLVE YOUR RIDING MOWERS & TRACTORS PROBLEM

Replace the riding mower mandrel assembly

The mandrel assembly attaches to the deck and spins the blade to cut grass. A blade won't move if the mandrel locks up. A damaged mandrel causes mower deck vibration and uneven cutting. Examine the mandrels regularly and replace any damaged mandrels.

Riding mower mandrel assembly

Find the required part specific to your product.

March 01, 2017

By Lyle Weischwill

How to replace a mandrel assembly on a riding lawn mower

If the blade shaft on your riding lawn mower vibrates or won't spin the blade, the mandrel might be worn or damaged. This DIY repair guide and vidoe explain how to replace a riding lawn mower mandrel assembly in just 6 steps.

Repair difficulty

Time required

30 minutes or less

Replace a riding mower blade

A bent mower blade won't cut grass evenly and may cause mower deck vibration. Dull blades leave ragged edges on cut grass. Inspect mower blades regularly and replace a riding mower blade if it's damaged, bent or dull.

Replace a riding mower blade

Find the required part specific to your product.

January 01, 2015

By Lyle Weischwill

How to replace a riding lawn mower blade

If brown, tattered grass tips make your lawn look sick, one or more blades on your riding mower could be dull or bent. This repair guide and video show how to replace a riding mower blade in 30 minutes or less.

Repair difficulty

Time required

30 minutes or less

RG-RM-Replace-a-Zero-Turn-Riding-Mower-Cutting-Blade-Intro-Image

January 01, 2015

By Lyle Weischwill

How to replace a cutting blade on a zero-turn riding mower

If your grass looks tattered after mowing with a zero-turn riding, the problem could be a dull or damaged blade. This easy-to-follow repair guide and video explain how to replace a blade on a zero-turn riding lawn mower.

Repair difficulty

Time required

15 minutes or less

Replace the riding mower 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. A worn blade belt can also cause mower deck vibration or uneven cuts. Examine the blade belt regularly and replace it if it's worn or broken.

Riding mower blade belt

Find the required part specific to your product.

January 01, 2015

By Lyle Weischwill

How to replace the blade belt on a zero-turn riding mower

If the blades won't spin on a zero-turn riding mower, the problem could be a broken blade belt. Replace a broken or worn blade belt on a zero-turn riding lawn mower by following the steps in this DIY repair guide and video.

Repair difficulty

Time required

30 minutes or less

RG-RM-Replace-a-Riding Mower-Blade-Drive-Belt-Intro-Image

January 01, 2015

By Lyle Weischwill

How to replace a riding lawn mower blade drive belt

If the blades on your riding lawn mower don’t spin fast enough—or don’t spin at all—the blade drive belt could be worn out or broken. This repair guide and video show how to replace a blade drive belt in less than an hour.

Repair difficulty

Time required

45 minutes or less

Replace the riding mower deck idler pulley

The deck idler pulley tightens the blade belt against the blade pulleys to spin the blades when you shift the blade engagement lever to engage the blades. You might need to replace the riding mower deck idler pulley if the blades don't spin. A worn idler pulley can also cause uneven cuts and mower deck vibration, so check the idler pulley if you notice these symptoms. Replace the deck idler pulley if it's worn or broken.