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Crankshaft Separation
As this forum is so slow, and I was busy today, with an itch to scratch, I'd thought I'd post this - it might stimulate comment Wink

Years ago, I used "fox wedges" and hardened Fiat 124 camshaft shims to separate crankshafts, but aligning four wedges, four shims, and using left and right hand simultaneously isn't something most folks can do, so I came up with a better way, if only to avoid the ridicule from some negatory souls that don't get it. Wink

The problem is whatever you do to a Panhard crankshaft it will always create an offset load, nothing I've seen addresses this easily, and these pesky crankshaft sure test the grey matter. The easiest & best solution is to make a small hole opposite the crank pin centre and use this as a push point, which by its nature is acting on the centre of the pin, and with clever supports, no rocking couple is introduced. It's nothing new the old Panhard crankshafts had a removable plug, so all you're doing is recreating this. Purists will say this is heresy, as you're ruining the balance, but the Panhard crankshaft is deliberately imbalanced to stop a destructive harmonic, and drilling a 10mm hole here is not a huge issue, but you can restore the status quo, if you feel the need by modding the flywheel further to compensate, or drilling another hole on the other crankweb. This way you can split from any side. 


As an example of a "Heath Robinson" approach, all you need is two or three aluminium blocks and two long straps of 15mm steel, although this could be refined with a bespoke laser cut plate, and some special standoffs, welded or affixed to it that sit on your press bed, but this simple approach will work. The minimum requirement for the hole is 10mm, as an 8mm carbide will shatter at the first press release shockwave, and 8mm silvered steel will deform at around 6 Tonnes, and BTW (typically) the Panhard crankshaft will release at around 7.5 Tonnes, and decrease thereafter as it moves out. The science of an interference fit says the first few millimetres and last few millimetres of the interference do all the work (stress distribution curves to be more precise look like a suspension bridge across the hole's axial section).


All you need is a small fastener of 10,8 or 12,9 strength like a socket screw (threads cut off - they will deform at the threads, I use a dowel pin), and a small larger diameter packer to take you up to the ram, and once centred, pump till you hear the "crack". After this it'll ease, on subsequent pumps, and before you know it, the crank web will fall onto that softwood packer you placed underneath.


Then flip the crankshaft over, and just push the exposed crankpin out, using another pin or cylindrical scrap of metal, like you do with any motorcycle pressed crankshaft. 


Hopefully you won't see this


All the best
Looks you've cracked it Mike ( pun intended )
Sounded quite a simple operation if you have a large press, but then I've never ventured that far with engine repairs.
Is that the crank from that old engine you got the other day ?
It's Humble to Stumble Tongue
No Adrian,

That's the crank I re-did for your old car's engine aka EYY177B, swapped the rod, but the other side went!
C'est la vie.

...knowledge is nothing without imagination...
That's obviously the best way, it's sheer common sense ! If the hioles are symmetrical why should it change the balance of the crankshaft ?
Anyway, you can always refill the holes after wards. Thank you for showing us. But your crankshat looks in good condition, as it seems. I've seen much worse ones !
Crank disassembly looks similar to a 2 stroke crank disassembly.
To my untrained eye, I can't see the damage to the crankpins, perhaps the reduced resolution?

The tracks where the cages run are proud of the roller tracks, so the surface steps in and out, and there is a chunk out on the top track to to left of the oil hole. The images are 400px wide, but I can zoom in on a tablet or PC browser.

Yes it might be similar to a motorcycle pressed together crank shaft, but a Panhard crankshaft doesn’t have separate crank pins or this type a hole to facilitate its separation. You have to do that, and put at least one in, preferably two. I use machining centres or CNC mills for accuracy.

...knowledge is nothing without imagination...
Keith just for you...


...knowledge is nothing without imagination...
Aww, you are the best, thanks for enlarging the detail of the damage.
Being a Japanese two stroke person for a long time, I am sad that putting in new crank pins is not an option - perhaps that is a consideration with a new crank?  That way a rebuildable crank with new pins never needs oversized bearings and a weaker pin or journal.
Another option is to go full 'Japanese' and have bearings with inner and outer races.  It does away with the Systeme Delagarde(?), but again makes future maintenance easy.
Peter Breed's method of sleeving reduces the basic strength, not preferable imho....
1964 Panhard 24CT

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