Power saw: How to change sprockets?

The pinion (or sprocket) in the chain saw is like many other components also subject to some wear. What types of drive wheels are in chain saws, when they must be replaced (wear limit) and how to make the exchange, read this post.

Types of sprockets

For sprockets, there are two different types:

  • the so-called ring gear and
  • the star wheel

The star wheel is a one-piece drive wheel, the chain drive and the clutch drum are combined here in one component. On the other hand, with the ring gear, which is also considered a higher-quality drive unit, the drive ring sits freely movable on the drive shaft. This results in smoother running and less wear.

In the case of a starwheel, the entire component has to be replaced; with a ringwheel it is sufficient to replace the drive ring (if there is no damage to the shaft, which is usually not the case). Replacing the ring is relatively easy.

wear limit

The wear of a sprocket is optically easy to see. In case of visible signs of wear, the sprocket (or ring) should always be replaced.

In addition, you should always exchange the drive wheel when changing the chain, where that is easy (ring gear). An already inserted chain ring can otherwise "hammer" the new chain and greatly accelerate its wear. Also, the rail can heat up strongly in such a "hammered" chain and is then subjected to increased wear.

Exemplary instructions

Below you will find instructions for changing a drive ring for an internal clutch. In other circumstances (completely visible sprocket, external clutch, star wheel or the necessary change of the complete drive component) you may have to proceed differently.

Changing the drive ring is quite easy and quick to accomplish, other work can be more complicated or complex and require more expertise.

Change drive ring - step by step

  • new sprocket
  • no special tools needed

1. Preparatory work

Release the chain brake and remove the side cover of the chain saw. Remove chain and rail. Thoroughly clean the motor housing (important!).

2. Remove old drive ring

Remove the circlip and washer. Now you can already remove the old drive ring.

3. Fit new drive ring

Fit the new drive ring with the label facing outwards (important!). Replace washer and retaining ring.

4. Assembly of the saw

Reinstall the rail and chain, place the side cover, and tension the chain. Perform a short test run (no noise, chain must go easily). Then retighten the chain again.

Tips & Tricks

If you have no experience with such work, you should leave the replacement of the sprocket necessarily the expert!

Video Board: How to replace the clutch and sprocket on a Poulan chain saw