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How to Replace a Qualcast Gear on a Classic Petrol 35s Lawnmower

Presuming due to manufacturing cost - the Qualcast Classic Petrol 35s lawnmower uses plastic gears and of course these would perish over time.

If your lawnmower is not performing as it should and you can identify the cause is faulty gears then don’t even consider shipping the machine to a repair centre because this guide will talk you through the simple process of replacing the gears on your lawnmower.

  What You Will Need:




  Step 1 - Safety Advice

Always make sure your lawnmower is switched off before you do any work. Just to be on the safe side either make sure the throttle is in the stop position or disengage the spark plug.

  Step 2 - Getting to the Drive System

There are three gears which we are going to guide you through the replacement process - to begin we first need to start by removing the side panel. This is held in place by four hex screws so using a hex screwdriver or torx screwdriver you can start to remove these.

With the panel off you will see the drive system - you will now need to remove the lower pulley cover, using a socket you can remove the bolt, once removed you can then slide the belt off. Next you can remove the pulley and you’ll now see how the gears fit and work.

Please Note:

On the particular version of the 35s shown in the video the gear on the pulley and the smaller gear on the drive system the same spare part.

Continuing on, you can now remove the cassette (the big rotary blade), held in place by two hex screws, these are on either side - once removed you can simply slide out the cassette.

  Step 3 - Replacing the Cassette Gear

To replace the cassette gear you need to first secure the rotating blades, to do this there are two options:

You can either hire the help of a friend, donning some heavy duty gloves the can just hold on to the cassette while you release the bolt using a socket.

Or the other option is to wedge an object like a piece of wood between the blade to hold them in place, the wood will help prevent damage to the cassette blades.

No matter which way you choose, after deciding use a large socket to remove the gear and screw the new one back on.

  Step 4 - Pulley Gear

For the gear attached to the pulley, you’ll see it’s held in place by three pins and it’ll just slide off. Now it might be quite firmly attached and using a flat-head screwdriver, you can work your way round and lever it off. Once removed you can then pop new one back on.

eSpares Top Tip:

Now if you’re having trouble you can separate the pulley from the gear and its plate, there are three screws that you can remove and will give you a bit more room to work.

  Step 5 - Lower Gear

Now to remove the final gear which is on the machine itself - you see that it is held in place by a clip, using a screwdriver you can lever it off. Once its come off the gear will now just slide away. You can then fit the new gear and then replace the clip back into position.

  Step 6 - Reassembly

With the gears all replaced you can now replace the cassette, refit the pulley and pulley cover and then secure the side cover back in place and you’re all done.

Well done you have just replaced the gears on your Qualcast Classic Petrol 35s lawnmower, for other guides to repair or maintain your lawnmower don’t forget to check out our other articles in our advice centre.

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