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

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In this video Helen shows us how to replace three toothed gears on a Qualcast 35s Classic Petrol 35s lawnmower.

Video Transcript:

Hi I’m Helen from eSpares.

The Qualcast Classic Petrol 35s is a great lawnmower. It uses moulded plastic toothed gears instead of metal ones. So, on the 35s, the first thing to go is usually one of these. Particularly this little pink one. In this video I’m going to show you how to replace them.

Now not all versions of the 35s use the same gears. So to ensure you are buying the correct ones always get the numbers from the data-plate on the back of the mower.

Safety first; always make sure the mower is off before you start any work, and to be on the safe side, either make sure that the throttle is in the safe position or just disengage the spark plug. You can never be too careful. 

To replace the gears I need to remove the cassette, and the side panel. I’m going to start with the side panel. It’s held in place by four hex head screws. So you’ll either need a hex screwdriver or a torx screwdriver will do, I’m going to use a torx key. 

So with the cover removed, we can see the drive system. I need to remove this pulley cover and then slide off the belt. I can then remove this pulley, and you can see how the gears fit together. Now, on this version of the 35s these two gears are the same spare part. So I’m going to continue by removing the cassette; it’s held in place by two hex screws, one on either side. You can then just slide the cassette out. 

To replace the cassette gear you need to first secure the rotating blades. So you can either get somebody to help you and get them to wear heavy gloves and hold on to the blades to secure them or you can wedge something in there like a piece of wood to hold them in place. Either way, just use a large socket to remove the gear and screw the new one back on. For the gear attached to the pulley.

It’s held in place by three pins and it just slides off. Now it’s quite firmly on there so use something like a flat-head screwdriver or chisel and work your way round to lever it off. And then pop the new one back on. Now if you’re having trouble you can separate the pulley from its gear and the plate, using these three screws and that will give you a bit more room to work. 

Now I’m going to show you how to replace the final gear on the machine itself. It’s held in place by a clip, and if you use, gain, a flat-head screwdriver to lever that off. So the old gear just slides off, and the new one slides on in its place. And then I pop the clip back on. Now getting the clip back on is quite tricky, so I’m going to use the edge of a socket to try and clip it back on. 

Now I just need to replace the cassette, put on the pulley, belt and pulley cover, and replace the side cover. 

There you go. That’s how easy it is to replace the gears on a Qualcast Classic Petrol 35s.

Spares and accessories for most makes and model of domestic lawnmower are available on the eSpares website.

Thanks for watching. 

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