Why Your Troy-Bilt Lawn Mower is Cutting Uneven (Fixed!)

You take a look at your freshly cut lawn and notice there’s something not quite right. The cut doesn’t look as nice as it usually does and you’re not sure why.

There are many different reasons why your Troy-Bilt mower can be cutting uneven. The good news is, most of the time, you can get your great cut back by performing some quick repairs and adjustments.

A Troy-Bilt lawn mower can cut uneven when the tire pressures are uneven; the deck components are worn or damaged, or the mower deck is clogged or not level. A bad cut with your Troy-Bilt mower can also be the result of operator error with a fast ground speed, slow engine speed, and incorrect mowing paths.

I’ll go through the steps to check and adjust your mower to achieve a great cut.

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Follow all safety instructions provided in your equipment operator’s manual prior to 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.

12 Reasons Your Troy-Bilt Mower Cuts Uneven

Troy-Bilt Mower Blade is Worn or Dull

When your blades are very worn, they can leave strips of uncut grass. Worn blades will become dull and thin when dirt and debris from your yard wear your metal blade.

This is normal wear and tear. A yard with a thin blanket of grass and more dirt circulated under your mower deck will wear blades sooner than a yard with a thick blanket of grass.

A sign your blades may be dull is when your great Troy-Bilt lawn mower lawn cut turns brown a couple of days later. I’ve wondered if my grass was unhealthy the first time this happened to me.

I grabbed a few blades of grass and noticed they were bruised with brown and torn tips. I immediately went and checked out my lawn mower blades and found they had been neglected and needed to be replaced.

My mower blades beat up my grass instead of giving it a nice cut.

Read more about when it’s time to replace or sharpen your Troy-Bilt mower blades in this article. I’ll share different methods to sharpen your blades at home.

Troy-Bilt Tire Pressures are Not Correct

You are definitely going to want to check your tire pressures before you move on to the next steps. If you don’t, you can make your uneven cut problem worse instead of better.

When you first notice your bad cut, it’s easy to assume the cause is in your Troy-Bilt mower deck. While most of the causes for a bad cut are due to some type of deck problem, it can be as simple as having a low tire.

If you don’t check this first, adjustments you make to your deck can be made in error. This means you will have to undo the adjustments once you realize your problem is in your tires.

When one tire sits lower than the other because of uneven tire pressures, your mower deck no longer sits level and can leave an uneven cut with your Troy-Bilt.

Using a tire pressure gauge check your pressures are to the manufacturer’s recommended pressures. Make sure pressures are equal on each side of your mower. If they are not, add air until they meet these pressures.

Once you have confirmed your tire pressures are correct and your mower sits even, it’s time to move on to check for a bent mower blade and uneven mower deck.

Troy-Bilt Mower Blade is Bent

A bent mower blade can cause your Troy Bilt to cut unevenly. Mower blades bend when there is impact with a solid object. This can be a rock, stump, or another item that could have been left in your yard.

To minimize objects that can damage your lawn mower blades, it’s a good idea to walk your yard and remove any objects you see before mowing.

Sometimes it is pretty obvious you hit something because a jolt is sent through the mower and you hear a loud grinding sound upon impact.

Other times, it’s not so obvious you hit something and you may not even think you need to be checking for a bent blade. I’ve seen blades bent at a 90-degree angle while others are only slightly bent.

Even a slightly bent blade can cause your Troy-Bilt to give you an uneven cut. It can also cause a vibration in your mower. There are a couple of ways you can check for a bent blade on and off your mower deck.

Just a reminder to always remove the ignition key and disconnect the spark plug wire(s) before you begin working on your mower deck.

• Check for Bent Troy-Bilt BladeMethod 1: Remove the blade and lay it on top of a new Troy-Bilt blade. This is a good way to verify whether or not your blade is bent, but you will have to take the time to remove your mower blade.

  If you prefer not to remove your blade or don’t have a new blade on hand to match your old blade, you can try the next method.

• Check for Bent Troy-Bilt Blade Method 2: Park your Troy-Bilt mower on a flat-level surface. Measure one side of the blade from the ground to the blade tip. Record the measurement.

  Next, rotate the blade 180 degrees and measure the other side of the blade from the ground to the blade tip. If the measurements are greater than a 1/8” difference, you need to replace your mower blade.

You can find steps to replace your Troy-Bilt blades here. Before removing your mower blade, I like to check for spindle housing damage that can occur when your blade impacts a hard object. Put on a pair of work gloves to protect your hands from your sharp blades.

Grab a hold of each side of the blade and rock the blade up and down. You are checking for any movement or a knocking sound.

If you experience either of these things, you need to remove your spindle housing and check for a damaged spindle or bearing.

Never attempt to straighten a bent mower blade to reuse it. When you do this, the metal is compromised and becomes weakened. It is possible for the weakened area to break off and fly out of your mower deck at high speeds.

This could cause injury or damage to people, pets, or objects in the area.

Troy-Bilt Mower Blades are Installed Incorrectly

When your mower blades are incorrectly installed with the sails of your blades facing the ground, damage can occur to your spindle housings and to your lawn. Instead of cutting the blades of grass, an upside-down blade will beat up and tear your grass.

This causes your Troy-Bilt to give your yard a bad and uneven cut. Every Troy-Bilt mower blade has a sail which is the high side of the blade. The blade must always be installed with the sail pointed upward toward the mower deck.

Some blade manufacturers will stamp the word “BOTTOM” or “THIS SIDE DOWN” on the blade to indicate which side of the blade needs to face up and which side faces down. If you don’t see any markings, don’t worry. Always remember “Sail Up!”

Another important step to keep in mind when installing your blades is to make sure they are balanced. If you are placing a new set of blades on your Troy-Bilt, you won’t have to worry about this.

If you are reinstalling a set of blades you sharpened, you need to ensure they are balanced for a good cut and to minimize damage to your mower and deck.

What is a balanced mower blade? This is when the weight on each side of the blade is of equal weight. If one side is heavier than the other, the metal must be shaved off of the heavier side until each side is of equal weight and balanced.

The most accurate way to check your blades is by using a blade balancer. A balancer is relatively inexpensive. It’s worth the investment because an unbalanced blade can cause significant damage to your Troy-Bilt mower.

Another method to check a balanced blade is by hanging the blade on a nail that is mounted to your wall with the nail head sticking out of the wall about 3/4″ to 1″.

You will need to remove metal from the end of the blade that is hanging lower until the blade sits level.

Troy-Bilt Mower Deck is Plugged with Grass

Grass buildup under your mower deck will give you a bad and uneven cut. The air movement created by your mower blades and the suction created under the deck is what creates a good cut from your Troy-Bilt.

When you take away the volume of area under the deck for air movement, the quality of the cut suffers.

A clogged deck can also affect blade speed and cause your engine to work harder when it needs to turn through thick debris.

There is no way to keep all grass and dirt from building up underneath your mower deck, but there are ways to minimize it so you can achieve a good quality cut from your Troy-Bilt mower.

• Don’t cut your grass while it is wet. Wet grass clumps and collects under your mower deck. It also leaves clumping in your yard.
• Use a silicone-type spray to coat the underside of your mower deck. While this does help reduce the amount of grass collecting under your deck, it will not prevent all grass from sticking. The nice thing about using a coating under your deck is the need to scrape your deck is less frequent.

Troy-Bilt Mower Deck is Not Level

A mower deck that doesn’t sit level can cause your Troy-Bilt mower to give you an uneven cut. Have your owner’s manual available to verify the exact specifications for your mower model.

While the instructions can vary a bit with each model, here are the steps to level most models. Start with your mower parked on a hard-level surface.

Adjust Troy-Bilt Deck Side-to-Side

Adjust your deck lift or knob to a middle position. Rotate your blade so the blade tip is at the right-hand side of your mower deck. Record the measurement from the ground to the blade tip. Perform the same procedure on the left-hand side of the deck.

If the measurements are not the same, make the adjustment needed to adjust the deck higher or lower as needed:

• Troy-Bilt Riding Mower: Loosen the hex cap screw on the deck hanger bracket you’ll find on the left-hand side of your mower. Do not remove the screw, only loosen it. To adjust the level, you need to turn the adjustment gear found behind the hex cap screw to raise and lower the deck.

  Use a wrench to turn the gear clockwise to raise the deck and counter-clockwise to lower the deck. Once the blades are even on both sides, retighten the hex cap screw.

• Troy-Bilt Zero Turn Mower: Loosen the jam nut on the adjustment bolt located on the side of the mower deck you want to adjust. Do not remove this bolt. There is an adjustment bolt located on each side of your deck.

  Adjust the bolt up or down until your ground-to-blade tip measurements are equal on both sides of the mower deck. Retighten the jam nut once the deck is level.

Adjust the Pitch of Your Troy-Bilt Deck

Your Troy-Bilt mower should be adjusted from front-to-rear. The pitch of your deck should be lower in the front than the rear of the deck. Measure the right-hand side of your mower using the blade closest to the discharge chute.

Do this, by rotating your blade so it sits parallel to your mower. Measure from the ground to the blade tip at the front of your mower and record the measurement.

Next, measure from the ground to the blade tip at the rear of your mower and record the measurement.

• Troy-Bilt Riding Mower: The front of your mower deck needs to be 1/4” to 3/8” lower than the rear of the deck. Make the adjustment as necessary by adjusting the stabilizer bracket. You will find a lock nut and jam nut on the front of the stabilizer bracket. Loosen the jam nut, but do not remove it.

  Raise the front of your mower deck by tightening the lock nut and lower it by loosening the lock nut. Once the front of your deck measures between 1/4” and 3/8” less in the front than it does in the rear of the deck, retighten the jam nut.

• Troy-Bilt Zero Turn Mower: For your zero-turn, the front of your mower deck should be between 1/16” and 1/4” lower. To adjust the front of the mower deck, find the lock nut and jam nut on the front hanger bracket. It may be located behind a cap. Loosen the jam nut, but do not remove it.

  Tighten the lock nut to raise the deck and loosen the lock nut to lower it. Once the measurements are between 1/16” and 1/4” lower in the front than the rear, retighten the jam nut.

Troy-Bilt Spindle is Bent

Check for a bent spindle or a failed bearing in your spindle housing that may be causing your bad cut. With a pair of heavy gloves on, grab a hold of each side of the blade and rock it up and down. Listen for a knocking noise and feel for any movement in the blade.

You will need to remove your Troy-Bilt spindle housing and inspect it for damage if you hear knocking or feel movement. Your spindle bearing is most likely bad.

Bad Mower Deck Belt or Pulleys on Your Troy-Bilt

When your mower belt fails to move around the pulleys at high speeds, your Troy-Bilt can give you a bad cut. Inspect your pulleys and deck belt to make sure there is no damage or wearing.

To check your pulleys, slowly rotate each pulley. A bad pulley is one where you feel resistance or hear a bearing noise when turning the pulley. Replace any pulleys you find bad.

You will notice your belt is bad when it has a worn glazed or shiny appearance. It may also become frayed, stretched, or cracked over time due to age or because of rubbing against other deck components.

Replace a bad mower deck belt with a compatible belt. I only use belts from the manufacturer so I know I’m getting a high-quality, correctly-sized belt made for my deck.

Troy-Bilt Engine Speed is Too Low

You must be running your mower at full throttle to give your mower enough power to keep your blades spinning at their top speeds.

If you notice you’re running it at full throttle, but your engine no longer sounds or feels like it’s providing the power it once did, you should bring your mower to your local Troy-Bilt dealership or a small engine repair shop to be checked over.

Troy-Bilt Ground Speed is Too Fast

Your ground speed needs to be adjusted to your mowing conditions to receive a good cut. If you don’t properly adjust your speeds and move too fast through your lawn, your Troy-Bilt mower will give you a bad or uneven cut.

Your lawn mower is put under heavier loads when it is cutting thick, tall, or wet grass than cutting in other conditions. You must slow down so your mower is better able to handle the load.

Incorrect Overlapping Path with Your Troy-Bilt

Making fewer passes with your lawn mower will allow you to complete your mowing quickly, but you may leave strips of uncut grass if you don’t properly overlap your cuts.

If your mower is new to you, it may take a little time to experiment with your mowing paths to make sure you are properly overlapping the cuts without overlapping too much and making your mowing job last longer.

Troy-Bilt Mower Deck Shell is Damaged

A damaged mower deck can cause your mower to give you a bad or uneven cut. You could have accidentally hit an obstruction when you got moving a little too fast. You may be able to repair your deck shell or you might have to replace it.

If you are having your Troy-Bilt dealership replace your deck shell, you may want them to quote a complete deck assembly as well.

Depending on the age of your mower deck and the amount of labor required to swap all your components over to the new deck shell, it might be worth it to just buy a new mower deck.

Your Lawn is Uneven

If you are like me and have a lawn that is not perfectly level, you may run into areas where your mower deck is scalping your yard. This can happen when you have a high spot in your yard. Another area where I see a lot of scalping is in shallow ditches.

A wide format mower deck can’t adjust with a bend or dip in the yard and therefore scalps the yard or creates an uneven cut. When mowing ditches, it is best to use a smaller format deck like those on a push mower.