I managed to drop a chainsaw clutch and it separated into its component parts.
Thinking there would be a simple trick to this, I consulted Youtube. It turns out that reassembling these has proved a challenge for many people, and their online posts informed as to what approaches don’t work well, describing the many hours spent trying to reassemble. One online expert advised
buy another, they are so cheap.
Above is a clutch of the type I will discuss, mine is from a 45-58cc Chinese chainsaw. There are variants, and the technique may be adaptable to them.
For this procedure, you will need a worm drive hose clamp just larger than the outside diameter of the clutch, and three packings to be described later to perform this two minute procedure.
So, there three clutch sectors (1), the spring (3) and the Y hub (4).
- Assemble the sectors and hub on a flat surface and using some drills or the like, work out a circular packing piece to insert (2) between each sector so that when clamped by the hose clamp, you can still easily lift the hub out. Making these packings larger diameter than necessary makes fitting the spring harder.
- Insert the packings (in my case, 3 x 6.5mm diameter rod 12mm long) and clamp the sectors tightly with the hose clamp.
- Fit the spring, it is hard but not too hard.
- Drop the hub into the assembly.
- Clamp the hub to sectors in a vice, and drive the packing pieces through.
- Remove the hose clamp.
- Take more care to not drop the thing!
Some designs might need flat packers rather than round ones.
This might assist people trying to reassemble these things.