Just a question for the boffins out there.....does anyone know of a catastrophic failure of a A series king pin?

I know they are a regular source of MOT fail but how far past a test fail, if hypothetically, Eh em, it had been passed, would one expect it to continue to operate safely?

Dunno about the boffinage aspect,
but I've seen an arm bent almost double following an accident, with the impact force having been transmitted from the road wheel via the hub carrier and kingpin into the arm.

Granted that the pin was in double shear, but it didn't fail.

A common sound on French campsites back in the 1980s was the rattle of loose kingpins on French registered A series as they crossed any bumpy ground, easily heard above the 2 pot's engine beat...

ken

mine failed the mot on a slack k/pin,/ top bush- there was only a little bit of play
the strange thing was--when i took the steering ends apart to fit rubber gaitors, one of the cups was split in half and one of the halfes was missing yet there was no mention of that

Cheers Ken - font of all knowledge as usual - I only ask our Sidewinder got failed then, once pumped with grease, went through OK.
I just got a little spooked as Mike has it up in Madchester and I remember that old Moggies used to crash quite spectacularly when their pins failed......

Wasn't it the trunnions on Morris minors that caused them to crash loads? I've seen one pin broken in half and that was in a Belgian arm and nobody noticed it until it was removed and they found it in two pieces.

I don't have any technicle info to explain but they seem to be made out of seriously sturdy stuff so should be ok. They dot wear a huge amount either !

if they,re a bit worn, at least the grease can get into the bushes !
i cant see how it gets into a new one, what with the bushes/pin being so tight
we replaced one on my brothers ak van a few days ago, then pumped the grease in-- the lever of the grease-gun locked solid once the grease had filled the kingpins
this was a BIG grease gun
maybye the grease was too thick

Morris Minors had threaded trunnions, top and bottom, and a threaded surface is not the best of bearing surfaces. The thread wears due to lack of grease, the wheel drops onto a pothole and on the rebound the threaded pin pulls out of the lower trunnion. Don't ask me how I know.

John