Mower deck protection

Mower engines go on and on but the deck often rots out, but there is a fix.

This video walks you through the process step by step, from preparing your metalwork to coating the underside of your deck.

Over View

You’ll find useful resources on this page, tips, links to tools, parts and supplies required to complete your repair.

I can’t help feeling a sense of loss when I see a good engine on a rusted out mower body. It’s only too common, mowers cut down in their prime.

Mower bodies can last as long as the engine, they just need a little help.

Cleaning the acidic grass from the underside before winterizing and storing indoors is a great start, but if you really want your mower to go the distance, undercoat the deck.

This video shows you how to love your mower.

Before working on your mower be sure to remove the plug wire to prevent accidental starting, see “Repair Safety Video”.

Tools & Parts

To nail this procedure you may need the following tools, parts and supplies.

Wire Brush Kit

Stainless for heavy duty and brass for and brass wire brush kit for heavy duty and finer applications like electrical connections and softer metals. Picture links to Amazon.com

Wire wheel

Wire wheel kit and a drill makes metal preparation easy, almost enjoyable! Picture links to Amazon.com

3M Underbody coating

This stuff protects the deck form corrosive acid caused by decomposing grass clippings. The coating also helps prevent grass clogging and reduces cleaning time. I use this stuff on my riding mower deck too. Picture links to Amazon.com

WD40

WD solves a ton of problems. I won't work without it, because I can't. Picture links to Amazon.com

Ratchet Tool Set

Before we can do anything, we'll need tools. I've selected this set as I own some Craftsman tools and while I have worn some out, they did do a lot of work. So I expect this set will last the occasional user quite a long time.

This set carries both metric and standard sockets and that's important, because some mowers will have both type of fastener sizes. Set includes spark plug sockets. Picture links to Amazon.com

Gas & Oil Syphon

You'll find this tool really useful if you need to drain the gas tank, and you will if the gas is stale. The siphon will remove it without fuss or mess and it can be used for extracting the oil too. Picture links to Amazon.com

Gas Line Clamp

Some small engines will have a gas tap, which is really handy when removing the carburetor, stops gas flowing all over the shop. However most engines won't have one, these useful clamps simply squeeze the fuel line and prevent a spill while you perform surgery. Picture links to Amazon.com

Impact Wrench

I love DeWalt, they're make quality tools. This heavy duty but lightweight 1/2 inch impact wrench makes short work of stubborn bolts like flywheel nuts and rusty blade fasteners. Upto 700 ft lbs of torque on tap, I keep one in the trunk of our family car, makes a flat almost enjoyable. Picture links to Amazon.com

Drill/Screw Gun

I use a Dewalt screw gun (also a drill) in the workshop to speed up the process of removing engine covers, carburetor bolts, Armature bolts etc. It's a brushless motor and as tough as nails, I driven over it a few times - still works great! Batteries are interchangeable and so if you have a Dewalt product already you won't need the battery. Picture links to Amazon.com
John Cunningham
Auto Technician and Writer at | Website

John Cunningham is an Automotive Technician and writer on Lawnmowerfixed.com. I've been a mechanic for over twenty years, I use my knowledge and experience to write "How to" articles that help fellow gear-heads with all aspects of mechanical repairs, from lawn mowers to classic cars.