My Tripod twistleg locks have fallen apart. Why is this and how do I fix it?

Q - My Tripod twistleg locks have fallen apart. Why is this and how do I fix it?

A - Many twistleg tripod locks like those used by Gitzo and Benro use a system of leg collars and anti-twist shims to allow the leg to be adjusted easily and quickly, with minimal effort. They are designed to be unlocked with a small movement (in the case of Gitzo tripods, they require just a 1/4 turn with finger and thumb to fully lock and unlock).

These leg locks are often designed to be user-serviceable so can be fully unscrewed so that they can be cleaned (an essential maintenance job any time the leg locks get submerged or splashed, particularly with saltwater which is very corrosive to the metal parts used.)  If the leg is loosened off too much, or the tripod leg is disassembled for cleaning, the anti-rotation shims, marked as 'c)' in the first image, can fall off and simply need to be re-attached and re-assembled.  This can be quite fiddly,so we have provided some instructions on how to do this.

The parts needed shown in the image below should all be present - these are the lower leg section (a), leg collar (b) leg shims, (c)upper leg section (d). You can clean these parts with a lint free cloth or simple soap and water, but ensure they are properly dry before re-assembling.  The shims do not need any kind of lubrication, but the metal collar can benefit from a very sparing application of grease TO THE SCREW THREADS ONLY, making sure not to get any on the internal friction surfaces.

Take the lower leg section in one hand making sure that the leg collar (b) is already on the tube, and locate the round protrusions in the inside of each shim into the holes on the tubing. (image 2)

When both shims are place it should look like image 3.

Note that the inside of the upper leg section (d) has a long thin protruding ridge running the length of the tube, and the small gap between the two white shims forms a groove for this protrusion to run in.  Holding the shims in place insert the lower leg section gently into the upper leg section and then rotate it until you feel the ridge slot between the shims, and then push the lower section in and tighten the leg collar.

If giving the tripod a full service, put the kettle on, settle in and repeat with the other 8 or 11 leg sections!