I had a lawn mower wheel height adjuster stuck hard a week or two ago. I bought it off a neighbor for $20, so I expected a few problems. I fixed it with a screwdriver and a hammer.
A couple of things can cause this problem. Random gunk can cause mechanical parts to seize, and lawn mowers fling grass clippings for a living. As they’re doing that, they’re going to find whatever random gunk is in your yard. Also, exposure to heat can cause spring tension to change. Of course, that motor happens to be a pretty good source of heat.
A good lawn mower mechanic may bristle at these suggestions, but when you need to get your lawn mowed, sometimes a caveman solution lets you get the job done.
That said, even cavemen should have limits. Don’t use a good screwdriver–use one of your cheap ones. This is the kind of job our fathers told us not to use a screwdriver for. Then again, our fathers didn’t have free screwdriver giveaways at Harbor Freight. Use those, and save your Stanley and Craftsman screwdrivers for their intended jobs.
The easy fix
Sometimes when the spring-loaded adjusters get stuck, just prying them back and forth with a big screwdriver a few times frees them up. Try that first. As long as you get the wheels adjusted to the level you need to get the job done, you can call it good.
Then again, if the adjusters move easily by hand afterward, call it better.
Bringing in the hammer
If you can pull the adjuster out from its notch but can’t quite move it up or down to the notch you want, try this. Pull the adjuster out, then slip a small screwdriver into the gap to hold the adjuster out, then try moving it by hand. If you still can’t move it by hand, tap it with a hammer. When you move the adjuster into position, pull the screwdriver back out, let the adjuster slip into the notch, and call it good.
Best of all
The other thing you’ll want to do is clean things up a bit. Keep it simple first and wash it with your garden hose the same way you would your car, paying special attention to the area around the wheels. Pressure from the water can loosen and break up whatever is in there keeping the adjusters from doing their job.
While you’re at it, flip the mower on its side and spray out the underside of the deck. Cleaning out the grass clippings and other debris helps keep the deck from rusting out.
After the bath, spritz the adjusters down with some WD-40. WD-40 isn’t a very good lubricant but it does a nice job of getting into crevices and loosening up whatever is in there. It will also displace any water in there, preventing rust.