Although it is operable, I've been told and I understand that my shifter is loose and a bit wobbly. It shifts fine, but it is fairly loose with you touch it and the heel shift has never really functioned properly. There is just probably too much "give" all around on it. I'm just not sure---does this usually mean the whole linkage system would need replaced or just certain pieces?

 

Do this: kneel down and shake it back and forth,see where the SLOP is. Repair or replace as needed.

 

Would also be a good idea to state which year/model bike you own...

If it is of the touring variety, it has a shift arm (two actually) which is mounted to a splined shaft that goes through a bore on the front of the primary case. Inside that bore, there are two brass/bronze bushings. On the other end of the shaft, there is another arm mounted on another splined shaft. That arm has a kind of ball joint, (unless somebody has replaced it with a heim joint), which a linkage rod goes back to the shifter arm at the transmission. That shifter arm at the transmission is mounted on another shaft with a spline...

So, as you can see, there are multiple points at which there could be excessive play introduced. You need to go from one end to the other, and remove/clean each point, especially the spline mounts on the shaft ends. This is where a lot of dirt/grime can get caught and will wear the splines to a point that tightening the bolt may not be securing the shift arm(s) adequately.

If there is play when you push the shafts in and out, then a spacer/washer may be required to take up the space. If there is play pushing the shafts sideways, or up and down, then the bushings should be replaced.

As for the linkage between the shift arms, if you do indeed have the old ball type joint, they will fail eventually, so I would suggest getting the heim joints to replace them.

When considering the heel shifter malfunctioning...
You should be able to adjust where it rides on the splined shaft. You can move it up or down on the spline, as needed to get proper clearance for shifting gears. You only need it to be high enough over the foot board so that when pressed down, it shifts into gear without touching the foot board.

The same thing goes for the toe shifter, with one exception...
Depending on if you use your toe to up shift or not, you may want the toe shifter just high enough to fit the toe of your riding boot under it. The lower the less discomfort you will have when shifting. If you are not going to use the toe shifter to shift up, then adjust it as low as you can to the foot board, but high enough so that it still engages the next gear.

Once you have done all that, you should be able to figure out if you actually need to purchase anything. Good luck!