pump to coupler connection -- help

I'm trying to understand the coupling system I have between the hydraulic pump and the flex coupling (to engine) in my old Bobcat 610. The pump shaft has a key that stays in one place. Key slot does not extend to end of shaft. Split collar with keyway sits on shaft. It has a flange on the pump side that one side of the flex coupling connects to. The hub of the split collar fits tightly inside the bore of the flex coupling. What I can't understand is: (1) what keeps the collar/coupling combo in the right place axially along the shaft, and (2) how to install on new pump, since I assume I shouldn't be pressing too hard on the end of the shaft. The flex coupling does not pull up tight against the flange of the collar. There are 3 cap screws that let you pull in up to wherever you want it, presumably for alignment. Thanks for any advice.

It sounds as though you are describing a taper lock bushing. There are mating tapers, one on the outside of the flange bushing, and the bore of the hub will also have a matching taper. When the 3 capscrews are brought up, they pull the hub onto the bushing. Go round and round tightening uniformly until they all stay tight. At that point the split bushing should have collapsed enough to be firmly gripping the pump shaft.

Note that there are also a couple of threaded holes in the flange of the bushing for the purpose of removing the bushing. First remove the 3 capscrews, then screw a couple of them into the threaded holes. Tighten them sequentially and they should pop the hub off the bushing as the tapers then are forced apart.

Thanks

Thanks. That explains the whole thing. Now that I have the coupler apart from the bushing, I can see the taper. I had wondered if that might have been the situation.