FH - clutch pushrod

 I usually make clutch pushrods for the simple reason that by the time I find that I need one I don't usually have the time to order one from one of the main suppliers. You can make them very easily with material from eBay or somewhere like that: they're just a 1/4" round silver steel bar cut to an appropriate length. Most Ariel ones are around 12 1/2" for the CP & BA boxes; later models with GB gearboxes are around 9 1/2" or so and are 5/16" diameter. Don't take these figures as gospel since there are a number of different variations in length due to different mainshaft lengths, different numbers of clutch plates, and the presence of friction material in the clutch basket in the last machines.

When you obtain the steel it will be in normal condition and will require the ends to be hardened. This is very simple - All you need to do to harden the steel is to heat the end to cherry red and quench it in water. 

First, before hardening you want to cut the rod to the right length. It's easy to find the right length, because the wonderful people at Draganfly provide a parts list which has the lengths recorded. If you're feeling guilty about using their information but not buying the parts rest assured that you'll be buying lots of bits from them at some point or other!

Start by marking and cutting the steel to the right length.

Next you'll want to square up the ends and smooth them off. You can use a file for this but I usually use my bench linisher with the mitre attachment set to 90°. With the end squared off I like to put a tiny bevel on the edges just to soften them.

Next step is to heat the ends and harden them. Some while ago I took one of the mini beer kegs and turned it into a small furnace with some ceramic blanket and fire cement. It makes heating this kind of thing very much more efficient, because it contains the heat from the torch. You use a lot less gas and the whole job heats up a lot more quickly.

Next you just plunge the end into a cold water bath, and turn around and do the other end; the middle part of the bar doesn't need to be hardened. You can clean off the oxide colours if you want to but it's not necessary. 

Pop your push rod into the main shaft and you're ready to build the clutch. 

By the way, these pictures show a 1/4" pushrod in a 5/16" hole. You live and learn!