Idler box question

[dbrick]

My Idler box is loose, but I go a nice tight replacment cheap. I noticed on the old one, still in the car, there are about 1/2 inch of threaded shaft protruding above the top threaded bushing, under the rubber cap. On the replacment, If I thread it in all the way and back out 1/2 turn, there is almost nothing protruding on top, but a gap between the arm on the bottom , when installed, and the 2 rubber washers that go up against the bottom of the housing. Is there a spec or procedure on how this is set up.
I have a housing with top and bottom bushing, a shaft and 2 flat rubber washers that were between the arm and box on the splined part.

Also, when greasinfg it 95% of the grease goes up the slot on the top threaded part of the shaft and comes out, none seems to get to the bottom bushing.

Any help appreciated

Dave