Your Ariens Mower is Vibrating: How to Make it Stop!

Mowing your lawn isn’t the most comfortable task, even before it starts vibrating. Finding and fixing your Ariens mower so you no longer feel like you’re going to shake out of your seat will not only make mowing a better experience, it will also prevent additional damage to the mower.

An Ariens lawn mower will begin vibrating when the engine mounting bolts are loose, worn, or broken; the ball bearing failed in the clutch; the blades are wrong or unbalanced; bearings failed in the spindle housing or pulleys; the deck belt is worn, or debris is lodged in the mower.

Always follow the safety guidelines outlined in your Ariens operator’s manual to avoid injury. Never work on the mower deck without first disconnecting the 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.

9 Reasons Your Ariens Lawn Mower is Vibrating

Engine Mounting Bolts

Without engine mounting bolts, your mower will feel significant vibration coming from your engine. A running engine will vibrate. To absorb some of this vibration, engine mounting bolts are installed under the engine.

Inspect the bolts, also known as motor mounts, to ensure they are not worn, broke,n or missing. Replace any engine mounting bolts found in this condition. Also, tighten any loose bolts.

If you own an Ariens push mower, there will be engine mounting bolts located under the engine. However, you will only need to check these bolts if you feel excessive vibration once you engage the mower blade.

Clutch

The ball bearing may fail on an electric clutch causing your Ariens mower to shake. The clutch needs to be replaced.

You won’t find a clutch on a push mower. Instead, you will have a lever that engages the blade. Check the lever for loose or worn components.

Mower Blades

The blades on a mower can be the cause of your vibration problem. Using an incorrect blade or a blade that is incorrectly balanced will cause your blade to rotate unevenly. It may even hit the deck shell if the blade length is not correct.

Wrong size mower blades:

I prefer to use OEM (Original Equipment Manufacturer) blades so I know I’m getting a high-quality blade with the correct fit for my mower. There may be some good aftermarket mower blades available, but you need to be careful when purchasing them.

Make sure they are of good quality and they have the correct center hole size and blade length. Just because the center hole size and blade length are correct, doesn’t mean it’s going to fit.

Ensure you’re getting a good match by laying an aftermarket blade on top of an OEM blade. Running the wrong blades on your Ariens mower can create additional damage to the mower.

Unbalanced mower blades:

A blade that weighs more on one side of the blade than the other is unbalanced. A blade can become unbalanced from uneven wearing during normal use.

This happens when the sand under the deck wears the blade mower on one side. It may also be the result of removing more metal on one side of the blade than the other during the blade sharpening process.

An unbalanced blade will not rotate evenly and can cause bearing damage in the spindle housing. This will create movement in the blade and a significant vibration when rotating at high speeds.

Keep your mower blades balanced using a blade balancer to confirm the weight on each end of the blade is equal. Find out more about sharpening and balancing your Ariens lawn mower blades here.

Material Wrapped Around the Blade Shaft

Before mowing your lawn, it’s good practice to walk the lawn and remove any items that can damage your mower if you run over it. Sometimes items get missed, especially items such as string, wire, and sturdy weeds.

These are examples of items that can become wrapped around the blade spindle causing the mower to shake. Remove any debris wrapped around the shaft. Proceed with checking the spindle and housing for 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 Ariens 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 and listening for a knocking sound.

If you feel movement or hear this sound, remove your mower blade and spindle housing. Inspect for bearing or spindle damage and repair the item.

Deck Belt

An Ariens mower deck belt that is stretched and worn will have slack where it doesn’t sit securely around the pulleys. Replace the deck belt when it shows signs of cracking, stretching, or a glazed shiny appearance.

Pulleys

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 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 Ariens mower 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 Ariens 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.