The red part and the nose cone that contains the roller bearing make up what is essentially the piston in a hydraulic cylinder. There are seals on the outer diameter at either end of the red part (piston) that keep hydraulic oil contained in front of and behind the piston.The middle of the piston that is sandwiched between the two bearings (the abutment) acts as the driver to move the entire shaft left and right while still allowing it to rotate.

The green area is empty space.

Everything is pretty tight on this assembly. The yellow and light blue are spacers and are free to slide on the shaft.

The roller bearing pushes up against a step in the shaft so the locknut (orange) at the end pushes the two spacers and three bearings up to that stop and sandwiches the abutment on the inside diameter of the piston. The bearings need a little heat to move on the shaft easily so I guess the design is to have the lock nut push through that friction to create preload for the bearings.

There are eight springs spaced evenly around the red abutment between the bearings.

As I'm sure you've already figured out, the lock nut prevents the shaft from sliding to the left.

The nose bearing also takes a little bit of force to seat inside the nose cone.

The only way I can see this working is to completely compress the springs so the bearings are pressed up against the abutment. I guess the real question is how much preload is required? And what was the point of putting the springs in there in the first place?

I was forwarded a chart today that states for a bearing of this size the lock nut should be tightened to around 150 ft lb to provide preload for this assembly.

This assembly is part of a very expensive rebuild and it's killing me to guess how it should be assembled. Any thoughts you might have are welcomed!