aixaix 

I'm guessing the problem isn't the axle. It looks like the housing isn't rigid enough to maintain the bearings parallel to each other, which is what equalizes the load across the pedal. If the housing flexes, the axle will too, breaking eventually. The MKS pedal (like the Campy Record & many others) uses a single casting to house the bearing cups. The Lyotard 460d does not, having an aluminum tube pressed into the steel bearing housings. It relies on the aluminum cage plates to deal with the considerable bending load the pedal takes. They flex, the hammered joints get loose and any time they hit the ground or anything else, the blow can easily misalign the bearing cup holders. The Marcel Berthet model doesn't seem to have this problem, perhaps because the barrel and platform are steel and don't flex much.

I hope you hear from users. It looks a lot like a design flaw to me, but I'm just guessing: I've never owned any.

I have a pair of Berthet Lyotards that have been in use since the 1960s on the bike I ride the most, by the way. They are my favorite pedals.