PAG logo


Welch plug mod.


Tom Rae

Or perhaps squelch plug? When I replaced my king pins I took great care to replace the Welch plug properly however despite my best efforts, it wept grease each time I applied the grease gun. Rightly or wrongly I grease the king pins after every ride and I was fed up of the excess grease making a mess.

Mike Bulley did a mod which involved tapping the welch lug and silver soldering a threaded rod into it, all very good if you can silver solder properly… My plan was to produce a 20mm x 5mm mild steel disc to replace the Welch cap at the top, this has a threaded hole in the centre. Barry kindly turned some for me, thanks again. I inserted a 20mm x 2mm O ring which sits on top of the kingpin bush and laid the disc on top. The location of the top kingpin bush is critical, it needs to be flush with the base of the housing otherwise it the 5mm disc will stand proud and the area needs to be dremelled to tidy up the “seat” clear any burrs

On the other end (the bottom) screw on cap, I drilled a central 6mm hole, this came partially in the screwdriver blade recess so I then drilled a 10mm counter bore 4mm deep. This provides a flat surface for the wee O ring sit on and reduces the protrusion of the cap head. On 2CV wheels there is not much clearance at this point. The final task was to fit a small O ring on the shank of the M6 135mm bolt and offer it up to locate in the thread of the top disc and gently tighten. I then trimmed off the protruding threads of the bolt. There is sufficient clearance for the CV joint but it is close so take care.

component parts

Here are the basic components

view of base

View of the base, care should be taken to ensure there is clearance for the 2CV wheel, most other wheel types should have plenty clearance.

View of the top

View of the top with the thread trimmed

Shopping list

Valid XHTML 1.0 Transitional Valid CSS!