Top Link Arm lock nut

[cobbadog]

On our 30C when driving along with the carry-all on sometimes the turnbuckle unwinds and drops the carry-all to the ground. Yes it is an easy fix to screw it back together but I feel it should not happen so I made a lock nut similar in style to the turnbuckle set up so that it looks similar. I started with a piece of solid bar and machined the surfaces then centre drilled the bar and kept drilling it out until I could get the boring bar in to bring it out to spec for tapping. I was going to use the lathe to make the thread but my tooling was not suitable to do so. I then marked out the position of the 3 short arms and drilled them and made some rod to use as handles to fit into the hole and then welded them in place. I noticed at the Clarendon Classic rally another 30C that had what looked like wire or maybe spring clips around both ends of the turnbuckle set up and there was slots in it and a pin going through. Looked tricky to make so I went this way.

[cobbadog]

All painted and refitted. Had to bend the 3 handles a bit to ensure they clear the PTO housing other than that it works a treat.

[Gard]

Nice job I was thinking of doing something similar, One question, if you could not cut the threads on the lathe did you find a tap to use? I looked briefly and it seemed my top link had a non standard thread so not a common tap.

[cobbadog]

Hi Gard,
My linkage was 1 1/4" BSF and I was lucky enough to find a NOS tap for AU$25.00 which was cheap. My boring bar could not cut a thread deep enough with one bar as it was not a big enough bore to fit it in and the other the tip was on an angle so would not cut the thread at the correct 55' pitch. If I could not find a tap at a reasonable price I would have went to an engineering shop and get them to thread it for me.

Best thing you can do to identify the thread is to buy a thread gauge and download a thread chart. Armed with that info you can identify almost any common thread used around the world from Metric, BSW, BSF and of course the imperial threads that use 60' pitch.
Its not until you start looking into things that you start to learn even more about topics. The tie rod ends on the 30C are a unique thread count and pitch and are almost unidentifiable. Then in the US in the early days Companies made their own thread counts and pitch and would not work with others. Thankfully those days are almost gone and there are a few common threads and can be identified.