A circlip (also called a snap ring) holds a gear, a bearing or a piston pin on a shaft or in a bore. It is made by stamping, so one side has a rounded edge and the other a sharp edge. The way round matters.
Rule
- Fit the sharp edge away from the thrust load. The load should push on the rounded side of the clip, so it cannot force the clip out of its groove.
Steps
- Before you remove the old clip, note which side faces out and which way the load pushes.
- Remove it with circlip pliers made for that type: pliers that close a clip for an internal clip, pliers that open it for an external clip.
- Check the groove is clean and not worn or damaged.
- Fit the new or old clip with its sharp edge away from the load. Make sure the clip is fully in its groove, round the whole circle.
- Turn the clip in its groove by hand to check it can spring and is seated.
Safety
- A clip can spring out and fly. Wear eye protection and hold the clip down with a finger or cloth as you open it.
- A piston pin circlip that comes out can ruin a cylinder. Always fit a new clip if the old one is bent or weak, and place the gap away from the cut-out in the piston as the manual says: Inspect a piston and read its size marks.
Check your work
- The clip is fully seated in its groove and cannot be moved by finger pressure.
- The sharp edge faces away from the load.
If it did not fix the problem
- A groove that is worn or a clip that keeps coming out: replace the part. See Circlips.