I took apart my KH 24 so I could take it on the train with me to Connecticut, but now I am trying to put it back together and it seems that one of the hubs (or cranks ((the metal piece that is exposed when the arm is removed))) is longer than the other. Is this normal or is somthing wrong? What I can see visually is that when the arm is put back on, on one side the metal piece extends further out ithan the other side.
JasonIf the axle is not exactly centered in the hub it’s not big deal. It’s only an issue if it is so far off center that one of the cranks cannot get completely tight (the retaining bolt will bottom out before the crank is tight).
Steve Howard has a gallery that shows a disassembled KH hub. Dissected KH Hub gallery That will show you what’s inside. If the axle is too far off center it can be pressed in the hub. The axle is just press fit inside the hub body.
If you need to press the axle back in you can use a bar clamp or a big C-clamp. See the thread How to press out Profile axle out of hub? for instructions on how to press the axle in or out of the hub.
If you don’t want to deal with pressing the axle back in you can just put on an additional spacer on each side of the hub. Go to a hardware store and find an appropriate size washer or bushing.
The axle can get pulled out of center if you really tighten the big retaining bolt on one side of the hub while the other retaining bolt is loose. The retaining bolts can move the axle inside of the hub body just like a bar clamp or a big press. The proper procedure for tightening the cranks on is to get the retaining bolt snug (but not tight) on one side of the hub then get the retaining bolt snug (but not tight) on the other side of the hub. After both sides are snug you can start cranking on them to get both sides really tight. Otherwise you can pull the axle off center.
beat it even with a wooden mallet!..only under my super-vision though 
PS, put the crank bolts back in the threads (no crank arm) then beat…so you dont get splinters of wood in there…a rubber mallet will nullify (sp?) that problema.
Just do not use a metal hammer. You can literally mash the end of the axle like a mushroom if you use a metal hammer.
Ok great, thanks. Just for clarification though, the retaining bolt is the one that screws directly into the axle, yes?
JasonYes. The big bolt that screws directly into the axle is what I call the retaining bolt. The smaller bolt on the crank is what I call the pinch bolt because it pinches the crank tight on the axle.