FIXED: Rear axle click clunk noise

juld0zer

neither the OEM nor the Kawasaki nuts are lock nuts afaik. That's why the cotter pin is there - to prevent the nut coming completely off. However in the 2011 model, the flange nut is covered by a castellated flimsy 'adjusting cap' which is supposed to prevent almost any free movement of the nut beneath. Because it is so flimsy, the castellated slots are easily defeated and the cap itself is a loose fit over the nut. Early models had just the plain hex nut with a cotter pin several millimetres away from the top of the nut. In this configuration, the torque spec is higher than the 2011 model with adjusting cap and flange nut.

because of the adjusting cap's flimsy construction, loose fit and the lax fit of the cotter pin in the axle hole, there is so much potential for it to eventually work loose and cause the clicking noise. I imagine the splines in the hub and axle are also quite a loose fit and hence the constant to/fro rotational forces work like an impact wrench to break the nut loose. The low torque spec for the flange nut (less than wheel nut torque) is surprising. For the adjusting cap to be effective, the potential movement it is designed to restrict/prevent must be only a few degrees - which means the nut it is trying to hold must be f'ing tight to begin with. But it isnt.

Anyway, back to your question - dont use any impact tools to tighten these nuts. If you cant tighten it to spec then get a larger breaker bar onto it.

The reason the Kawasaki nut worked for me is because it is both tight (tad tighter than factory spec) and unable to move (castellated slots are barely big enough for the cotter pin to fit thru so it's a very snug fit.
Again, i apologise for any inconvenience i have caused due to me not accounting for various OEM configurations. I hope that you can all resolve this issue successfully - please post up any relevant pics so future visitors may gain from our collective experiences