This guide will show you how to remove the gearbox from a 250cc AJS Model 14 / Matchless G2 or a 350cc AJS Model 8 / Matchless G5 motorcycle (all years).

You will need a set of Whitworth spanners or sockets and a decent flat-bladed screwdriver.

Note that the bike featured in this guide has a few modifications from standard, so your bike may look a little different in places. The basic technique remains the same, regardless of which model of Lightweight you have.

Remove the six screws holding the primary drive cover on.
  • Remove the six screws holding the primary drive cover on.

  • You can either drain the oil first, or just put a dish underneath to catch the oil spillage.

  • Lift the cover away. Note that the cables to the alternator will still be attached, so make sure the cover is supported and not pulling on the cables.

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Unscrew the clutch springs with a piece of flat metal.
  • Unscrew the clutch springs with a piece of flat metal.

  • Lift off the clutch cover and withdraw the clutch operating rod and clutch plates.

  • Engage a gear and undo the clutch retaining nut. This is likely to be tight; it will undo more easily if you "shock" it loose with light hammer taps onto a socket driver.

  • If you are lucky, the clutch will be loose on the shaft. If it is stuck fast, you may need to use the special puller.

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  • Remove the kickstart.

  • Remove the gear position indicator (if fitted) and the gear lever.

  • Remove the exhaust.

  • You may need to remove other ancillaries such as footrests and chain cover (not shown in these pictures)

  • Remove the link from the rear chain and move it clear of the gearbox sprocket.

  • Drain the oil from the gearbox.

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  • Undo the four screws holding the right side cover on and remove it.

  • Some trapped oil may run out if there are any leaks on this side of the engine.

  • Undo the two screws holding the inspection cover on and remove it.

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  • Slacken off the clutch cable completely at the handlebar end and release it from the clutch lever.

  • Push the cable through to release it at the gearbox end.

  • Look in through the gearbox inspection hole and release the cable from the operating fork.

  • Withdraw the clutch cable from the gearbox and put it to one side.

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  • Remove the two barrel bolts from the gearbox retaining bands.

  • Remove the two nuts holding the tensioner in place.

  • Withdraw the tensioner and the two spacers either side of the gearbox mounting tab.

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  • Remove the two nuts at the rear of the mounting plate.

  • Lift the mounting plate away.

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  • You can now lift the gearbox away from the bike.

  • Don't forget to hold on to the clutch basket on the other side of the bike. It will fall away as you remove the gearbox.

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See my other guide on how to overhaul the gearbox...

Paul Barnfather

Member since: 05/30/2017

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2 Guides authored


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