How to Repair Lawn Mower Deck | Repair Rust, Holes & More
To repair your lawn mower deck, you’ll need to start by removing the deck and the spark plug so that you can inspect the deck for cracks or rust. You can then weld and clean the deck surface and sharpen or replace the blades. Finally, remember to check the mounting hardware before adding lubricant and reattaching the deck.
How you fix your lawn mower deck depends on what material it’s made from, what the nature of the damage is, and how proficient you are at mending certain components. In this article, Mowrator will discuss how to fix a rusted lawn mower deck and how to repair holes in a lawn mower deck. Plus, we’ve provided more steps in the repair process so that you can repair your mower deck yourself.
Tools Needed for Lawn Mower Deck Repairs
The tools needed for repairing a lawn mower deck will depend on what type of lawn mower you have, the nature of the repair, and what material the mower is made from. We’ve put together a list of tools, what they are used for in the repair process, and approximately how much each tool costs.
Safety Equipment and Personal Protective Equipment (PPE)
You should always use personal protective equipment (PPE) to ensure safety during repairs and welding.
| Tool | Use in Repair Process | Approximate Cost (USD) |
|---|---|---|
| Safety Glasses | Protect eyes from debris during grinding and cutting | $5 to $15 |
| Welding Shield | Protects face and eyes from welding sparks and intense light | $30 to $100 |
| Welding Gloves | Protect hands during welding operations | $15 to $30 |
| Welding Coat | Shields body from sparks and heat while welding | $40 to $100 |
Metalworking and Repair Tools
You can use these tools to cut, weld, grind, shape, and repair metal components.
| Tool | Use in Repair Process | Approximate Cost (USD) |
|---|---|---|
| Sheet Metal Welder | Welds metal patches or repairs cracks in the deck | $200 to $500 |
| Flux-Core MIG Welder | Welds without the need for external gas | $300 to $600 |
| Grinder | Removes rust, paint, and smooth metal surfaces | $50 to $150 |
| Grinder Cutting Disc | Cuts through metal components as needed | $5 to $15 |
| Grinder Flap Wheel | Polishes and finishes metal surfaces after grinding | $7 to $20 |
| Chipping Hammer | Removes slag and welding residue from welded areas | $8 to $15 |
| File | Smooths rough edges and removes burrs from metal surfaces | $10 to $20 |
| Ball-Peen Hammer | Shapes metal and assists in removing dents | $15 to $30 |
| Locking Pliers | Securely grips and holds components during repair | $10 to $20 |
| Adjustable Wrench | Loosens and tightens various nuts and bolts | $10 to $25 |
Preparation and Finishing Tools
You can use these tools to support, mark, clean, and protect surfaces before and after repairs.
| Tool | Use in Repair Process | Approximate Cost (USD) |
|---|---|---|
| Concrete Blocks | Elevate and stabilize the mower for safe access to the deck | $1 to $3 each |
| Wood Blocks | Support and secure the mower or deck during repairs | $2 to $5 each |
| Paint Marker / Caulk / Marker | Mark areas for cutting or welding | $2 to $5 |
| Wire Brush | Cleans metal surfaces by removing rust and debris | $5 to $10 |
| Primer | Prepares metal surfaces for painting to prevent rust | $5 to $15 |
| Paint | Coats the deck to protect against corrosion and enhance appearance | $10 to $20 |
Most of the components in your lawn mower are made from metal, so some welding knowledge will come in handy when repairing a lawn mower deck or any of its inner parts. In some cases, you will need to replace components (blade, deck, engine parts, etc.); however, typically, you’ll be able to repair them yourself.
How to Repair a Rusty Lawn Mower Deck
To repair a rusty lawn mower deck:
- Disassemble the deck and clean off the rust
- Disconnect the spark plug so that the lawn mower can’t switch on while you work
- Use a wire brush to clean off rust and dirt
- Repair any noticeable holes, apply anti-rust primer, and reassemble the mower deck
Tips for Applying Anti-Rust Primer and Paint
When it comes to applying rust-resistant primer, there are three steps to follow:
- Coat the entire part of the deck with primer
- Let it dry completely
- Apply anti-rust paint
How long does rust-resistant primer take to dry?
- Fast-drying primers take around 10 to 30 minutes until it’s touch dry, but you should wait 2 hours before applying the paint.
- Standard primers can take 1 to 4 hours to dry before it’s safe to apply the paint.
- Heavy-duty or high-build primers take up to 24 hours for full curing, so make sure you read the primer instructions before moving on to the next step.
How long does rust-resistant paint take to dry?
- If the paint is a spray application (fast-drying rust-resistant paint), you should leave it for a full 24 hours to fully cure before reassembling your mower deck.
- If you’ve used oil-based or enamel paint, wait 48 hours.
How to Repair a Hole in a Lawn Mower Deck
To repair holes in your lawn mower deck, follow these steps:
- Determine which holes are small enough to fill with metal epoxy, and which need welding to repair.
- For very small holes (under 0.6 inches or 1.5 cm), you can simply fill them in with metal epoxy. Follow the manufacturer’s instructions carefully.
- For large holes, you will need to weld metal plates onto the deck to completely cover the hole.
You may find small or large holes in your deck during your inspection. Even the smallest hole can compromise your mower deck with rust, so inspect carefully to identify all holes or cracks in the metal.
You can also solder small holes closed if you have a soldering iron, but metal epoxy works just as well. If welding large holes is not something you know how to do, take your lawn mower deck in for professional repairs.
How to Repair Cracks in a Lawn Mower Deck
Follow these steps to repair cracks in your lawn mower deck:
- Disconnect the spark plug
- Removing the deck
- Clean the deck thoroughly and inspect for cracks.
- Drill a ⅛ inch hole at both sides of each crack to prevent crack spreading.
- Now grind a V-shape along the crack and begin the welding process.
- For the welding, you will need to use a stick welder or an MIG to fill the groove you made with the grinder.
The V-shape grinding (also referred to as bevelling) will allow the welding to fully penetrate the crack, so this is an important step if you want your repair to last long term.
- Once the welding is done, use your grinder again to make the repair flush with the deck.
The crack will be filled during the welding process, and the grinding will flatten the repair so that the lawn mower deck reassembles properly.
When should You Replace Your Lawn Mower Deck?
You should replace your lawn mower deck if you notice that it’s beyond repair. If holes, dents, or cracks are too far gone, it’s often cheaper and quicker to simply purchase a new one. If the lawn mower no longer functions optimally, buying a new deck can restore it to working condition.
How much does a Lawn Mower Deck Replacement Cost?
Push mower deck replacements can cost up to $200 or less. Riding mowers are significantly more expensive at around $300 to $1,000. A zero-turn mower deck replacement can cost anywhere between $400 and $2,500, depending on the make and model. So, the cost of replacing your mower deck will depend on the type of lawn mower you have.
Always remember to check your other lawn mower parts. In some cases, the damaged deck can compromise the inside of the lawn mower. Visit Mowrator to browse for lawn mower parts that may need replacing.
How to Replace a Broken Lawn Mower Deck
To replace a push lawn mower deck:
- Disconnect the spark plug
- Drain the fuel
- Remove the blade and disconnect the old deck
- Carefully detach any wires and components and note where they should go
- Now attach the new deck and reattach the necessary wires and parts
- Fasten the deck in place
- Reconnect the spark plug and refuel the mower
Replacing Riding and Zero-Turn Mower Decks
Replacing a lawn mower deck on riding and zero-turn mowers requires a more intricate process of jacking the mower up and removing the drive belt. Finally, you’ll need to remove any brackets holding the deck in place.
For some mowers, you will also need to remove the deck wheels before sliding the deck out and replacing it. Once a riding or zero-turn mower deck has been replaced, you will have to reattach all of the parts you removed. The driver belt will need to be rerouted, so make sure you pay attention to how it was routed when you removed it.
FAQs on How to Repair a Lawn Mower Deck
How do I repair a lawn mower deck belt?
To repair a lawn mower deck belt, remove the deck and the old belt and take note of how it’s fitted along the pulleys. Install the new belt and align it the same as the old one. Check the tension and make sure it spins properly with the pulleys before reassembling the deck.
How do I repair non-metal lawn mower decks?
To repair a plastic or fiberglass lawn mower deck, remove the deck and drill ⅛ inch holes on both sides of the cracks. Fill the cracks with plastic or fiberglass epoxy and allow to dry for 24 hours. Paint the deck to protect the repairs and reassemble your deck.
How can I tell if my lawn mower deck spindle is bad?
You can tell when a lawn mower deck spindle is bad by listening out for rattling noises or unusual mower vibrations. Uneven grass cutting is another sign that the mower spindle is damaged. You can also inspect the spindle and check that it’s aligned properly and that the bearings are not worn.
Why is grass sticking to my lawn mower deck?
Grass may be sticking to your lawn mower deck because of a dull blade, too much moisture in the grass, or because your deck needs a new coat of moisture-resistant coating. Cleaning your mower after every cut can also prevent excessive grass from sticking to your mower, since existing dirt attracts more debris buildup.
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