elimn8u

I am a tech and these specs came from the Yamaha service manual. The spacer is there but there is room to allow preload for the bearings. To much preload from overtighting the bearings and you burn the up prematurly. To little preload and you ruin the bearings. You decide, I know how I set my preload.

In order to ensure the longest life for the bearings they need to be properly preloaded. Simply just tightening the nuts is not good enough for me. Step 1 - tighten inside nut to 40ft/lbs Step 2 - tighten outside nut to 140ft/lbs while holding the inside nut Step 3 - tighten BACK the inside nut to 170ft/lbs while holding the outside nut

The nut is 50mm. I made two "crowfeet wrenches" to tighten mine. This socket method won't work for the final step in the factory procedure. You need to be able to torque the inside nut while holding the outside nut.

I don't know for sure about on an atv, but on an automatic transmission for a car antifreeze attacks the glue that bonds the friction material to the clutch plate. Sounds like this is may be your problem. Hope that this helps.