Some fasteners are very particular about how tight they are. Overtightening a mower blade bolt for example could cost you an engine, too loose isn’t good either. Using a torque wrench removes the need for guessing and this video shows you how to set a torque wrench, use it and care for it.
A torque wrench is a specialized tool used to tighten fasteners (Nuts & bolts) to a precise factory spec setting.
Overtightening or under-tightening fasteners can cause injury or component damage. When you’ve been turning wrenches for years some less critical fasteners may be tightened by feel but critical bolts such as blade bolts should be tightened to factory spec.
Each mower model will have a different spec and you’ll need to check the torque spec with your mower maker. (Google has the answers) You’ll find other uses for a torque wrench. Ever struggled to remove lug nuts? That’s because they were likely overtightened.
Before working on your mower be sure to remove the plug wire to prevent accidental starting, see “Repair Safety Video”.
You’ll find useful resources on this page, tips, links to tools, parts, and supplies required to complete your repair.
Tools & Parts
To nail this procedure you may need the following tools, parts, and supplies.
Teng 1/2 Torque wrench, a fantastic tool I use it every day, and mine are still going strong. A torque wrench is advised for tightening components such as flywheel nuts and blades. The torque spec of these components is very important. Picture links to Amazon.com. If you’re buying a torque wrench, check out my review of Teng torque wrench, it’s the wrench I use.
This is the first tool on the list for good reason, 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 types of fastener sizes. Set includes spark plug sockets. Picture links to Amazon.com.
I love DeWalt, they 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. Up to 700 ft-lbs of torque on tap, I keep one in the trunk of our family car, which makes a flat almost enjoyable. Picture links to Amazon.com.
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 drove 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.
Piston Stop Tool
Universal piston stop tool 10mm and 14mm, used to lock the crankshaft when removing and tightening the flywheel nut. Picture links to Amazon.com.
Blade Sharpening Tool
Handy blade sharpening kit that fits a cordless drill, includes blade balance tool. Picture links to Amazon.com.
Blade Holding Tool
The very useful blade holding tool is used to hold the blade steady while the blade bolt is loosened and tightened. Picture links to Amazon.com.
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 and drill make life easy and the job almost enjoyable! Picture links to Amazon.com.