You just need new bearings, two 8mm Allen keys (but you can make do with one), your bike’s forks, and a few miscellaneous washers.
You should inspect all of the hub’s part before you begin to reassemble it, to ensure that the hub will perform as close to new as possible when you’re done. Inspect the hub shell for cracks, and make sure that the aluminium centre axle doesn’t appear bent, bashed, worn, stripped, or cracked.
Take the (C.) centre axle and slide the (A.) hub shims over each end.
Slide one of the (B.) hub bearings over one end of the axle.
Insert the axle assembly into the (G.) hub shell and slide the (B.) other hub bearing over the end of the axle that doesn’t have a bearing already.
Take one of the (F.) 3/8 Allen bolts and slide a (D.) hub washer and then an (E.) Cone Spacer over it, and then thread it into the centre axle a few turns. For the other side of the hub, take the other bolt, the hub washer, and then 3 or 4 (*1.) standard washers (whatever you have lying around your tool bench, about 1/4-1/2″ worth), and then the cone spacer. Thread this onto the centre axle. You can get it finger tight. Then, place the other axle bolt into the (*2.) dropout of your fork (on the outside), and tighten it down until it’s snug.
Now, tighten down each side gently, making sure that you’ve got the bearings aligned straight and they are being smoothly drawn into the hub shell.
Continue tightening both bolts evenly until you feel the bearings bottom out. Loosen up the bolts, and remove the hub from the dropout. You can loosen the opposite side completely and remove the washers. With the cone spacers removed, the bearings should be inset a millimetre or two.
You’ve done it!
You’re hub should be running smoothly again.
Incidentally, overhauling rear hubs and hubs with 14mm axles is more or less done the same way as the 3/8″ Allen bolt axles, only the axles and locknuts are different. I’ll do an update on overhauling 14mm and rear 3/8 axles with complete instructions soon, but the principles are the same.
Thanks to Cody for his brilliant work as our hand model.