How To – Replacing The Drive Belt On Your Push Assist Lawnmower

If your lawn is too small to justify a riding lawn mower but too large to use a manual push mower then your best option is a Push Assist Lawnmower that will help you get around your yard without the need to push a heavy mower.

When they work right a Push Assist Lawnmower will carry all the weight of the mower and a full bag of clippings or leaves. All you need to do is walk behind it at a modest pace.

When you need to get under or around bushes or in tight areas you simply let go of the assist lever and it becomes a standard mower that you can push and pull at your own pace.

The Drives on these lawnmowers are really not that great. You can expect yearly maintenance and although there are no adjustable parts the wheels are often plastic while the gears that drive them are steel and this means they won’t last very long.

A pair of drive wheels for our Craftsman Lawnmower cost about $10 a piece so $20 for parts then add shipping or the gas to drive to the Sears Outlet .. and every year we end up replacing a set. Unfortunately all brands are the same. Steel on Steel gear sets are not available probably because they would end up causing more problems.

The second weak spot is the Transmission. You can expect to get 5 to 7 years out of the transmission. Ours is about dead. You can tell it is about dead because it will not release for non power assisted moving, the wheels lock when the engine is off, and also when the engine is on one wheel is slower and weaker then the other.

Finally you have the drive belt. They are basically standard automotive fan belts or accessory belts. they have a v shape and fit into pulleys that are mounted on the shaft that exits the engine just above the cutting blade and then run to the transmission just above the axle for the front wheels.

Although it may be possible to replace the drive belt with a Automotive belt the kits you order from your manufacturer will also include a transmission mount bolt and spring. They need to be replaced when you replace the belt because flexing of the spring over time will cause it to become stiff.

Replacing Your Lawnmower Drive Belt

Ok so lets get started replacing this drive belt.

The first thing you need to do is remove the spark plug wire and tape the opening so no spark can get to the combustion chamber. Accidents do happen and if you have heard the horror stories I have you would never forget this step. We won’t go into it here in detail but Professionals I have met have lost parts of fingers doing this for a living and they have told me of people with worse outcomes.

The tools are pretty basic for this job you will need

Socket Wrench Set

Screwdriver and or Pry bar

Small brush

To replace the drive belt on your lawnmower you most likely will not need to remove the cutting blade or pulleys.

Starting with the lawnmower on all four wheels remove the deck cover that protects the drive belt. It should be one or two bolts that hold it in place.

Now place the lawnmower on its side so you can access the blade area and clean the cover and mounting bolts on the bottom belt cover.

Remove the bottom cover and then clean all of the grass and debris from the cover.

Inspect the belt and take note of the way the belt fits through the deck opening.

To remove the belt you will need to place the mower back on all four wheels and press the transmission pulley towards the engine to produce enough slack that the belt will come off.

Compressing the transmission spring enough to produce the slack is difficult because as springs get old they get stiff. You will see that your replacement spring compresses much easier. Take your time and compress the spring. If you just can not get it loose you can cut the spring bolt and remove the belt.

The belt will slip out from under the lawnmower. Place the lawnmower on its side and remove the belt noting how you have to slide it around the housing and blade to get it off because installing the new belt will be the exact opposite. You should not have to fight it to get it off once you get it off the transmission pulley.

Install the new belt and place the end through the deck opening.

You will now need to cut off the transmission mounting bolt if plastic and remove the old spring. If your mounting bolt is not plastic you will need to follow manufacturers directions on how to remove it.

Replace the spring and mounting bolt BEFORE you try to mount the new belt. If you mount the belt first you will never be able to align the spring bolt and it should be a locking bolt which means you only get one shot at it.

Make sure that the belt is attached to the engine shaft pulley then run one edge of the belt around the outside of the transmission pulley on the top side of the lawn mower.

Just like when you took the belt off you will need to compress the spring to get the belt around the pulley. This will take some brute force so be careful and maybe ask someone to help.

Once theĀ  new belt is on both pulleys you can attach the lower cover under the lawn mower.

Keep the top cover off and test your work by running the engine with power assist enabled.

Make sure the belt does not slip when you have the lever fully engaged at the lawnmower handle.

You can now replace the top cover.

Final Note about replacing your lawnmower push assist belt

This is not a difficult job but it does take some muscle to get the belt over the pulleys.

It is also a slightly dangerous job working on your lawnmower with it tilted on its side. You must remove and protect the end of the spark plug wire from contacting the spark plug while working. Take this precaution seriously or bring your mower in for service. This is not a joke and not a game.. take it serious.