Swapping a Harness Buckle to the Other Side

If a harness is fitted with the buckle on the outer strap there is a risk of the buckle damaging the paintwork when hanging over the side. It may even dent the panel.

However it's quite easy to swap the buckle to the inner strap. (The example shown is a 'Luke' four point harness cam lock buckle - though I imagine most other types are likely to be similar.)

Removing the label reveals a screw which holds the handle onto the central shaft. With the handle removed two screws become accessible which hold a cover plate.

With the cover removed the operation of the buckle becomes clear. The central shaft operates a cam which lifts a plate through which five pins protrude (one of which is unused in a four point application). Four of the pins are 'top hats' and one is plain, and each has a spring which acts against the cover plate to hold the pin in the locked position. Ramps on the pins allow the strap tongues to push the pins back against their springs as they're inserted.

When the cam is operated the four 'top hats' are lifted with the plate releasing three of the strap tongues but the plain one remains in place, so permanently connecting that strap.

To swap the fixed strap from one side to the other the plain pin is simply swapped with the 'top hat' from the opposite side, and the cover and handle replaced (using Loctite on all the screws).

The original Luke labels are a thin plastic, and often seem to be damaged. (Perhaps they're made deliberately fragile for tamper detection?). As such they may not survive removal. I've replaced mine with laser printed self adhesive labels covered in matt Selotape ('Magic Tape'). They seem to be quite sturdy but I'll try a polyethelyne 'heavy duty outdoor label' material if they don't last.

The image and PDF below should print at the correct scale to produce circular labels 23mm in diameter. The colour may appear wrong on screen but produced a good match to the original when printed on an HP Laserjet. (It might need tweaking for a different printer.)