Ford Transit Mk5 17mm Propshaft Bearing Spanner, hand filed & case hardened.
Site includes CAD file in dxf format.
Page link: https://knoba.wordpress.com/2014/04/...aring-spanner/
I have to say that, Ford never made (to my knowledge) a special tool for this job, but I felt one was required as none of my other standard spanners could gain adequate access to the bolt. The 2 intermediate prop-shaft bearings on my vehicle are notorious for failure and making a special tool seemed reasonable. If Ford had made a special tool; I would have bought one.
The first questions to ask are:
Open-ended or ring?
34mm is pretty big. How much torque will the wrench have to take?
How much is "occasional use"?
Any special requirements, like shaping (my spanner has a slight offset dog-leg in the profile to account for the universal joint knuckle in the prop-shaft)?
Evaluation of these questions, together with your; tooling, methods & materials will determine the final product.
Last edited by knoba; 04-15-2015 at 04:27 AM.
A quick answer would be mild-steel, 3mm / 4mm thick (the max. thickness applicable to most bicycle headstock nuts?) with extra allowance around the jaws for strength.
The long answer, is take you through how I might go about it, with basic tools, and then you can bob & weave depending on what's available...
A google image search for iterations of a "34mm bicycle wrench" pulls up what features of each iteration look good (comfort handles, a hole for wall hanging, few stress risers around the jaws, finish, etc.).
I'm guessing that a bicycle headstock locknut would have to be torqued in the region of 20-30lbs/ft. If the wrench is 8" long it would require about 30-40lbs of force to apply the correct torque.
Using a CAD package (I use LibreCAD), a template can be made that can be stuck to the piece of metal plate and worked to shape, like this one (download & have a play)...
knoba - 34mm bicycle wrench - 2015 - Rev-1.0.dxf
It's worth checking out freecycle or freegle (or any online public recycling website in your area) for items that may include the materials that the item requires (mild steel plate 4mm thick x 65mm wide x 204mm long). An old cylinder mower perhaps, a computer chair or an old metal bed...
My pneumatic planishing hammer was made from an old trampoline (total material costs, including the new air chisel; £30).
My Trammel set used the pushrods from a pair of knackered Audi 80 rear shock asorbers (total material costs; £4)
If the material has to be bought, this should be fine (but I would prefer some thicker material); Parker steel - 65 X 3mm EN10025 - Mild Steel Flat
or the 5mm preferably, if suitable for the max. thickness applicable to most bicycle headstock nuts; Parker steel - 65 X 5mm EN10025 - Mild Steel Flat
Use some spray adhesive to stick the CAD print-out to the metal plate...
Shape using; vise, hand tools, grinders, etc. and leave the jaws unfinished until ready to size them accurately on a spare nut.
If the tool is going to be stamped with its size, or the owners initials, now is the time to do it!
Finally, case harden the wrench and only quench the jaw end. Old schoolers used to use old leather scraps, bones etc. for colour casing and it produced a gorgeous patina on the metal that is sadly lacking today as seen on this lovely Moore & wright surface gage...
That's it (just one way to skin a cat)!
Last edited by knoba; 04-16-2015 at 08:06 AM.
Traditional color case hardening (done with bones, charcoal, etc.) produces one of the most beautiful finishes that can be applied to steel. It's my favorite firearm finish of all time.
A few random pics can be seen here: Color Case Hardening
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