I don't know. I also don't know if the pinion shaft diameter is smaller on the later locker. It would be interesting to see the 2 units side-by-side to compare them.

It makes sense that the 9.5" rear would have a larger diameter pinion shaft, so it's entirely possible - maybe likely - that for the later lockers, Mitsu simply turned the companion flange to a smaller diameter and mated it to the smaller yoke and u-joint.

My question is "Why?" - maybe for the same reason I see with the amount of flange protrusion? Or was it so they could minimize the number of parts they made across all product lines?

It would seem that the larger yoke and companion flange would be stronger - but if it experienced a higher incidence of strike damage, the failure rate might be more than the smaller unit.

As has been said, the problem is probably more imagined than reality..... particularly if the truck sits in the garage. <img src="/forums/images/graemlins/lol.gif" alt="" />

Frank