There are several good things about the Tune Kong hub from a servicing point of view:
- no special tools are required for complete disassembly;
- freehub/pawls can be serviced with no tools whatsoever;
- bearings are standard sizes, available at just about any bearing shop.
It's a good idea to check on the condition of your pawls and ring drive gear at least once a year, or more often if you ride in dusty, muddy or wet conditions. The process is simple and can be done without any tools:
- remove the drive side end cap by pulling it off;
- take care to remove any bearing preload shims which sit underneath the end cap;
- grab the freehub and pull it away from the hub, slide it off the axle (note: if freehub is difficult to remove, reinstall the cassette and use it to pull on the freehub);
- clean the pawls, springs and drive gear (in the hub) - I like to use some mineral turps and a toothbrush for this - taking care not to get too much on the bearings;
- inspect the freehub bearings, replace if necessary - suitable bearing pullers and a press make this easier, but I have used a screwdriver, hammer and a socket when I had to do an emergency bearing replacement while on a cycle tour;
- relube the drive gear with two drops of synthetic motor oil;
- reinstall the freehub buy sliding onto the axle, turn in an anti-clockwise direction to assist engaging the pawls with the drive gear;
- put the preload shims back on;
- put the end cap back on;
Main bearing replacement
Follow the instructions for freehub removal, then:
- remove the axle by driving it out from the drive-side to the non-drive side;
- heat the hub shell to 60 deg C (Tune assembles the bearings with Loctite 603, the heat will help to break the loctite bond);
- press the bearings out using whatever tools you have at hand that will work.
- 2 x 61803-2RS (17mm x 26mm x 5mm) in freehub;
- 1 x 61803-2RS (17mm x 26mm x 5mm) and 1 x 61903 (17mm x 30mm x 7mm) in hub shell
Freehub bearings do not have a spacer between them. Proper bearing preload is set at the factory with thin shims that sit between the outer freehub bearing end and the end cap. Take care not to loose these shims and put them back when you're done.
Note: older Kong rear hubs featured a special double row bearing and may require special tools.