That makes good sense, except for the fact that if the cavity in the center is empty, the grease will flow away from the bushings sooner, maybe.
What's you're take Crok?

 

Sorry again for the late response, but yeh, the holes which the grease exits the shaft are usually mid-point of the bushings. Turning a shallow groove around the shaft coinciding with the position of the exiting holes, as 1FLTRI4ME suggested, can indeed assist in assuring grease is applied to the entire surface of the bushing. Be fore warned that this may also give way for a weakening of the shaft itself, depending on the diameter of the inner drilling. The thickness of the metal between the shallow channel, and the inner diameter will be thinner, and therefore possibly create a weakness in the shaft.

Being as the shaft does not make a complete rotation during use, this limits the dispursement to some degree. But then, the force of the grease gun is usually ample enough to provide adequate lubrication. This is not as critical as it may seem. There is not (usually) a lot of movement or pressure applied when shifting gears. The bushings simply require a small amount of lubrication to prevent premature excessive wear.

Even when worn severely, that part of the mechanism rarely fails to operate. It's just annoying to hear that rattle, to those of us who are obsessively meticulous. I am one of those myself, so don't take that as criticism.

When applying the grease to the new bushing after the assembly, just keep squeezing the gun until the grease is seen to exit the complete circumference of the shaft, on boths sides of the inner primary housing. You will lose quite a bit (insert 'path of least resistance' concept here), depending on how long it takes to fill the cavity. In fact, it may not be necessary to completely fill the cavity for ample lubrication to be applied. And, it may exit one side sooner or even more on one side than the other. Be prepared to catch the excess with paper towels or something. But after this initial application, you can be pretty well assured that only a squeeze or two will suffice from then on.