Introduction: Repair a Broken Mower Handle
I've been using the same old reliable 6.5 HP B&S powered 22" MTD Yard Machines push mower for about 15 years now. This mower has seen a lot of use, and abuse. Even though maintenance has been lacking, it keeps on hacking. These are indicators of a well engineered robust machine. That said, I believe that my subtle mods have contributed to it's longevity. For example, the adaptive engine cooling vents that I've allowed to form in the deck at a precisely calculated rate in sync with engine wear. To the untrained eye these vents may appear to be random rust holes, au contraire!
Speaking of random rust, the user interface i.e. the handle recently failed due to a corrosion induced stress fracture. Let's repair it and dare I say, improve it!
Step 1: Trim Off Dead Ends
I measured from the inside of the top of the lower handle section to the pivot pin hole and made a note of this measurement.
Preparing to Cut
- I chose to replace both handle ends, even though only one was broken.
- I measured a few inches above the flattened out section and marked the same distance on both sides.
- You could use a hacksaw, reciprocating saw, jigsaw, or what I used, a 4" angle grinder with a metal cutting wheel.
- Try to be precise and make square cuts.
- Once both ends were trimmed to length, I cut a slit down the end of the tube at the midpoint about 1" - 1 1/2" long. Then made another slit 90 degrees perpendicular on both ends.
- It's a good idea to debur the cuts with a grinder or a file.
Step 2: Full Metal Jacket
I had some 3/4" ID EMT electrical conduit that proved to be a good fit for replacement stubs. The OD of my mower handle tubing is approximately 7/8". The slits that I cut down the ends of the tubes are to remove enough material to allow the tube ends to form into a taper that fits inside the 3/4" conduit.
- Referring to the measurement that I took before cutting off the intact factory end I calculated what length stubs I needed to cut. I added about an inch to the measurement to slip over the tapered tube end. And I added another inch to have some meat below the pivot pin hole.
- I again used my angle grinder to cut the two peg-legs, arr shiver me timbers matey.
Step 3: Hammering Out D Flat
The factory handle ends are stamped totally flat. In my opinion this is a bad design. I decided to only flatten out the side of the tube stubs that contact the pivot pin bracket, and handle angle stops.
- I drilled a hole in the wide face center of a scrap chunk of 2 x 4 the OD of the conduit. Then I split the chunk in half on my table saw creating two half circle saddles to support the tube stubs. This will help maintain their curvature on one side while I hammer out the other side flat.
- With the saddles resting on a concrete cinder block and with the stubs riding in the saddles, I hammered out a flat 4" up from the bottom on both stubs.
Step 4: Drilling Is Pivotal
With the stubs temporarily slipped on the ends of the handle tubes I measured for the pivot pin holes, referring to the measurement that I took note of earlier. The flats of the stubs need to be facing squarely in toward each other.
Due to the radius at the top of the handle section, the tape measure can't be aligned flush against the face of the tubing. I used a strip of wood to help transfer the length measurement accurately.
- To establish the center mark, with the handle assembly lying on a flat surface I used pieces of wood with a thickness totaling half the diameter of the tube as gauge blocks.
- I setup the saddle blocks on my drill press to support the stubs while drilling.
- I first drilled a small diameter pilot hole.
- Then I drilled the finished hole, sized to accept a copper tube bushing that I'll tell you how I made next.
Step 5: I'm About Bushed
One flaw in the original handle ends in my opinion, is that there was no bushing lining the pivot pin hole. As you can see the pivot pin hole in the broken end is wallowed out. I decided to make some bushings out of scrap 1/2" copper plumbing pipe that I had. I needed to reduce the ID down to 3/8" to fit the pivot pins. A couple of these would have simplified things.
- To determine how much of the bushing blank needed to be removed to reduce the tube diameter I whipped out a calculator. I used metric measurements for simplicity.
- I added two times the wall thickness of the copper tubing to the ID I needed to end up with, then multiplied that by pi (3.14) to get the outside circumference.
- Then I cut a paper template to wrap around the tube to mark the section that needed to be cut out.
- I used a tubing cutter to cut the blank to length, about 1/8" longer than the width of the stubs.
- I clamped the blank in a vise and used a hacksaw to slice out the section.
- Using a 3/8" bolt as a form I started with pliers roughly crimping the bushing around the bolt.
- Then I used a hammer to refine the roundness.
Step 6: A Flare for Flanging
To secure the bushings in place I decided to flanged over the ends.
With a flat head bolt, which has a conical under-head, I used it as a flaring tool.
Once both sides where flared, I hammered the flares into flanges.
Step 7: Getting a Handle on It
- I installed the stubs on the pivot pins.
- I slipped the tube ends of the lower handle section into the stubs.
- Then I hammered the lower handle section firmly in place.
- Next I drove some drill screws through joint to secure the stubs to the lower handle section. Those with welding equipment could weld the joint for a more stable connection.
- Lastly I reattached the upper handle section.
After already deciding to do this repair I discovered that Stens makes a repair section for this very problem. My solution was more cost effective and a superior design IMNSHO.
We have a be nice policy.
Please be positive and constructive.