This is Why Your Bad Boy Lawn Mower is Vibrating (Solved)

Using your Bad Boy lawn mower feels like you’re literally riding on a jackhammer. The excessive shaking is enough to drive you crazy. Not only do you need to resolve the problem for comfort’s sake, but not doing so can cause additional damage to your mower.

A Bad Boy lawn mower may start vibrating when hardware, bushings, and linkages are loose; engine mounting bolts are loose or worn; clutch ball bearing has failed; mower blades are unbalanced; bearings have failed in the pulleys or spindle housing, or debris is lodged in the mower.

Before performing any work on your Bad Boy mower, always follow the safety guidelines outlined in your owner’s manual. This includes setting your parking brake, removing your ignition key, and disconnecting your spark plug wires.

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Follow all safety instructions provided in your equipment operator’s manual before diagnosing, repairing, or operating. Consult a professional if you don’t have the skills, or knowledge or are not in the condition to perform the repair safely.

Reasons Why Your Bad Boy Mower is Vibrating

Bad Boy Mower Engine Mounting Bolts

Your engine sits on mounting bolts, also known as motor mounts. These bolts exist to absorb the vibration felt through the mower when the engine is running.

Inspect these bolts to make sure they are not loose. Tighten any loose bolts and replace any that may be worn or broken.

If you own a Bad Boy push mower, check out your engine bolts if you feel excessive vibration in your mower once you engage the mower blade.

Clutch

The ball bearing may fail on an electric clutch causing your mower to shake. In a manual engagement clutch, the bushing and linkages can fail to cause a vibration. A manual clutch is used with belts and pulleys.

A push mower does not use a clutch. It uses a lever to engage the blade. This lever needs to be checked for loose or worn components.

Mower Blades 

Your Bad Boy mower blades can be the cause of your vibration. Using the wrong blade or a blade that isn’t correctly balanced can cause problems. An incorrect blade or unbalanced blade rotating at very high speeds can cause damage.

Wrong size mower blades:

The correct blades must be installed on your Bad Boy lawn mower. Your blade must have the correct center hole size along with the right length.

I choose to use OEM (Original Equipment Manufacturer) blades. That way I know I’m getting the right blade for my mower deck.

All aftermarket mower blades will not fit even if you have the correct blade length and center hole size. Physically match the aftermarket blade to an OEM blade to verify it is correct.

In the past, I have purchased aftermarket blades with the correct measurements from two different suppliers. Blades from one of the suppliers did not fit my mower.

Unbalanced mower blades:

Blades that are not balanced will not spin evenly. It can cause bearing damage in your spindle housings that allow movement in the Bad Boy blades.

At high speeds, a significant vibration will be felt throughout your mower. An unbalanced blade is when one end of the mower blade is heavier than the other.

This can happen with uneven wearing or removing more metal off one side of the blade when sharpening or uneven wearing.

Make sure your Bad Boy blades are balanced by using a blade balancer before you install blades on your mower. Find out more about sharpening and balancing your blades here.

Material Wrapped Around the Blade Shaft

I always recommend walking your lawn before you mow it to remove any items that can damage your mower like rocks, toys, and sticks. While you make every attempt to avoid items that can damage the mower, you may have missed thin narrow items such as string or wire.

These items can be picked up and wrapped around your blade shaft causing your Bad Boy mower to shake. Even a long narrow weed can get wrapped around your blade shaft.

Inspect your shaft and remove any items that are wrapped around it. Once this is done, check your spindle and spindle housing for further damage.

Bad Spindle Housing Components

Bad bearings or a bent spindle in your spindle housings can cause your blades to wobble when you engage your blades causing vibration in your Bad Boy mower deck.

Before you check your spindle housing, put on a good pair of work gloves to protect your hands from the sharp edges of the mower blade.

Grab a hold of each end of the mower blade and rock it up and down. What you’re doing is looking for any movement. You may hear a knocking sound from the extra movement.

If you feel movement, remove your mower blade and spindle housing. Inspect for bearing or spindle damage and repair.

Mower Deck Belt and Pulleys

Your pulleys and mower deck belt may cause your shaking problem. When the belt is worn or has slack in it, it will not sit securely around the pulleys. Replace a worn belt if you find it is stretched, cracked, or has a glazed appearance.

If the belt appears in good condition, make sure it is routed around the pulleys correctly and the tension is adjusted to remove extra slack. Your belt may also not be sitting securely around the pulleys because the pulleys are not sitting parallel to the deck.

Check each pulley to make sure it is securely attached to the deck and doesn’t have a wobble to it. You don’t want a lot of movement in the pulley where one side of the pulley sits higher off the deck than the other.

When this happens, you most likely have a bad bearing on the pulley. Find a failing bearing by slowly rotating each pulley by hand. Feel for a restriction and listen for bearing noise.

If you experience either of these, your bearing must be replaced. Note: Some pulleys will only use sealed bearings. In this case, you will have to replace the pulley and bearing assembly.

Idler Bracket & Spring

A loose idler bracket and spring can make your Bad Boy shake. The bracket and spring are both subject to wear over time. The hole in the bracket where the spring attaches can wear larger and the spring can become stretched. When this happens, you will experience a vibration.

Replace a worn idler bracket or spring. Check the bearing and bushing in the engagement linkage and replace them if you find they are worn.

Debris Lodged in the Mower

Check your mower for small debris stuck in the mower’s components and in small crevices of the mower.

When mowing the lawn, your Bad Boy mower kicks up the debris that can collect on your mower. Something as small as a wood chip can cause extreme vibration in your mower.

Remove your spindle covers and clean off your deck regularly. Debris can collect under your pulleys and cause them not to sit flat and parallel to the deck. Vibration is created when your mower deck moves around the pulley.

Look every part of your mower over carefully and remove any items that are lodged in your mower. It is best to clean your Bad Boy after each mowing to keep it free of debris not only to prevent vibration problems but also corrosion from moisture in the debris.

Need help with cleaning procedures? Check out “How to Clean Your Mower for Best Performance“.