[Joe K]

Not to dispute.

And what is the point of the normal "semi-interference fit" between double shell bearing and the punkin housing - a fit which requires the tool for pinion/shaft removal?

Not trying to puncture a statement - but there must be a reason. It might be as simple as "positively locating" the pinion in the proper relationship to the ring gear. That would be the point of the pre-load.

An axle minus the torque tube recently arrived (thank you Craigslist) with a home-made removal tool attached and in place. Somebody had started the disassembly and lost heart. The axle had been sitting in a Maine field for the last generation. I was glad to actually now own the tool.

Joe K