[6pack] Speaking of flywheels

[Douglas Morris]

A while back my engine wouldn't crank, jammed hard; but everything from the
clutch back was nice and free. I thought perhaps the backup bolt I installed
on the throwout bearing fork had lost its nut and jammed the ring gear
(perhaps due to stupidly re-using a nylock nut or somesuch). Nope, wasn't
that. Two of the three small alignment pegs for the flywheel/pressure-plate
interface came out, and one jammed between the ring gear and the case (no
damage, just a few light scratches on the case, but the pegs are obviously
toast). All the bolts were fully tight, and I re-torqued 'em with no
movement.
Two questions:
1. What would cause these to pop out?
2. Are they really necessary for operation, or are they just for installation
alignment?
Okay, three ... three questions:
3. Did I screw up somewhere?

Doug Morris, NC, '74 TR-6 CF-18xxx-UO