They say that necessity is the mother of invention. I guess that is especially true when you are working on old cars, far from their home land.
Recently, I helped Cor B to get his 2CV6 back on the road after winter storage. During that work (oil change and cleaning and gapping the spark plugs), I noticed that some drive shaft boots were torn. We ordered the required parts from Michel L in Montréal.
While I was waiting for parts to arrive, I popped onto one of the Internet forums devoted to the 2CV. Since I had never tackled this particular job before, I decided to see if anyone had any handy advice about how to replace the boots.
One of the common comments was that the hardest part was getting the small ends of the boots over the larger splined end of the outer drive shaft. There were allusions to it “being like trying to put a condom on an elephant”. Everyone pretty much agreed that it was a slightly miserable struggle complicated by the fact that your hands will be covered in nice slippery black grease as you are trying to do it.
The general recommendation was just to persist, stretch it around progressively, or use needle-nosed pliers to help get it started.
Then I vaguely remembered someone telling me, long ago, about a technique that involved forming a cone over the splines, to make it easier to stretch the rubber boot. That got me thinking, and I started looking around the garage for material. My eyes settled on a 150 ml bottle of gas line antifreeze (1L LHM for scale):
I got to work with my trusty Opinel knife (what else would one use to make a Citroën tool?), and here is what I did:
To use it, you position the large end of the tool onto the splined end of the drive shaft.
The small end of the tool is just the right size to go through the large end of the boot, and into the small end (or directly into the small end for the intermediate boot).
Grease the cone of the tool, then start pulling on the boot.
The taper of the cone will encourage the small end of the boot to strrrreeeeettttttccccchhhhh until it is large enough to pass off the cone and onto the splines.
At that point, you just need to slide it the rest of the way, until the small end of the boot comes off the splines, and settles into its recess in the shaft. Voilà, just like a magic trick!
We wound up doing the outer boot once, and the intermediate boot three times (please don’t ask why!), and the tool worked very well each time. There is a bit of effort required, but I suspect that was because we were a little hesitant to pull too hard on the body of the boot. I don’t think we really needed to worry about tearing a brand new boot.