Lawn Mower Wheel Won’t Turn

Pushing a mower isn’t fun, especially a self drive model, they’re even heavier. But help is at hand and you are in the correct place for self drive repair. I’m a mechanic for over twenty years and I’ve repaired a ton of these type issues.

A mower wheel won’t turn for three common reasons:

  1. Drive belt worn
  2. Drive cable broken or needs adjustment
  3. Wheel worn

In this post you’ll learn how to diagnose why your mower wheels won’t turn and you’ll learn how to fix them right now.

Worn mower drive belt

Worn out belt

1 Mower drive belt worn

Mower drive systems are driven by a belt and two pulleys. The belt is fitted to the engine’s crankshaft pulley which drives a second pulley on the transaxle.

The drive belt works really hard, despite this they tend to last years without issue. Belts of course wear out over time, no big surprise there.

Loose mower drive belt

Loose drive belt

A worn belt commonly results in the belt:

  • Breaking
  • Becoming loose
  • Constantly jumping off

Common symptoms of a worn out drive belt include:

  • Mower won’t move
  • Mower slow
  • Mower slows on hills
Mower tilted over on correct side

There's a Wrong way

Checking The Belt

Mower tilted over on correct side

Drive system

To check the belt the mower will need to be turned on its side. But before we do that we’ll need to remove the spark plug wire to prevent accidental starting.

A mower may only be turned over the carburetor side facing upwards. Turning a mower incorrectly will cause the engine to flood with gas and oil possibly preventing the mower from starting.

I wrote  post about turning your mower over correctly and you can read about it here, “Which way to tilt your mower”.

In addition if your mower has a fuel tap, turn it off. You can read all about finding and using your fuel tap here “Mower fuel shut off valve”.

Mower axle belt Mower crankshaft pulley

Belt on both pulleys?

With the mower turned over, air filter side up, check  the belt is fitted around the transaxle pulley and crankshaft pulley. Most mowers are rear wheel drive and so the transaxle is located at the rear wheels.

If the belt is around both pulleys, go ahead and check it’s tight. If the belt is in place and tight, move on to the next section. The belt isn’t the reason the mower wheels aren’t moving.

If on the other hand your belt is loose, broken or has jumped off, you’ll need to replace the belt. It is possible to refit a jumped off belt, but you’ll soon be refitting again. Belts usually jump off because they are worn out.

Mower tilted over with drive belt off

Jumping off? Replace belt

Fitting a new belt is a job you can take care of, however some mowers are challenging to work on. Many will require blade removal and some may require partial removal of the rear axle.

Mower drive cable adjuster Mower drive cable adjuster

Drive cable adjuster

2 Mower Drive Cable Needs Adjustment

Mowers use a belt and pulleys to get power from the engine to the axle, but all that power is useless without control. Power is controlled by way of transaxle lever, attached cable and bail lever at the handle bars.

Cables are just bicycle brake or gear cables, they are a two part cable black outer casing with a steel braided inner cable, and like a bicycle cable they break or stretch out over time and need replacing or adjustment.

All good drive cables will have a user friendly adjuster that allows for easy drive cable adjustment.

How to check if your drive system needs adjustment?

To check if your drive cable needs adjustment, apply the drive bail lever at the handlebars and drag the mower backways.

If the cable is adjusted correctly, the drive wheels will lock, if they slip, we’ll need to adjust.

Mower drive adjuster

Check for slack

How to adjust the mower drive system?

First locate the drive cable, follow the cable from the transaxle to the bail lever to confirm you have identified it correctly. Now look for an adjuster screw, commonly it’s at the handlebar anchor where the cable fixes to the handlebars. Otherwise an inline adjuster may be fitted.

All adjusters will incorporate a lock nut. Open the lock nut and adjust the outer cable to remove slack from the inner braided cable.

Mower inline adjuster Mower inline adjuster

Lengthen outer to remove slack

Before tightening up the lock nut check by applying the bail lever and pulling the mower backways as before. Repeat this process as necessary.

When it’s adjusted, pull the mower backways this time without the bail lever applied. The wheels should turn freely. If they don’t back off the adjuster until they do, now your drive cable is adjusted correctly.

Check out this post, “Honda self propelled slow” it covers a Honda drive adjustment in greater detail, but all mowers run similar setups.

If you need video help check out the video library where the complete repair is covered, start to finish.

Mower rear wheel gear Mower drive gear

Mower wheel

3 Mower Wheels Worn

Most mower wheels are made from plastic and many use a plastic gear inside the wheel. The axle drive gear which is metal, wears away the plastic wheel drive gear and the mower drive slips at first and then eventually loses drive altogether.

The only fix is to replace the wheels.

To check the drive wheel we’ll need to remove them. A single fastener in the center of the wheel removes the wheel, however a plastic wheel cap will likely conceal the fastener. A flat screwdriver will pry loose the cap.

Loosen and remove the fastener and the wheel pulls off. Check the gears inside the wheel, if they’re worn you’ll need to replace them. Best to replace both axle wheels.

While the wheel is off go ahead and check the drive axle pins. They wear out on older mowers, it’s all covered in this post “Honda mower slow” .

If you need video help, check out the video library, replacing wheels and axle pins is covered start to finish.

Mower drive pin

Axle pins

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.