I found a nice set of old Shimano 105 clip pedals for my vintage bike. As you might imagine, one is smooth as silk and the other rough and gritty.
I popped the bad one apart and found an odd thing. Looks like the spindle/axle has three "steps" for bearings, one at each end (as you'd figure) and another in the middle, just to the other side of the small end.

When I took out the spindle, there were NO bearings in the big end. This would account for any failure of the bearings....

Anyone familiar with the design of these things, or where I could get an exploded diagram? (Could'nt find one on the Shimano site)

I've never seen a pedal with three bearing races, and I'm wondering if the previous owner just didn't assemble 'em wrong.