The manual shop doesn't specify a torque reference for the front disc spindle castle nut and I guess there isn't one but I have heard tighten it than go back 1/4 of a turn as heat will expand the metal (any truth to it?) but when I do so there is a little play in the wheel. What is the correct way?

 

I tighten it until there is no wobble play in the bearings and then tighten to the nearest slot in the castle nut to get cotter pin in. I like a tiny bit of preload on my wheel bearings. It's a touchy feely thing for me.

 

^^X2. Tight. But not TOO tight.

 

You are right I don't believe that there is a spec its got to do with the amount of load the bearing has when manufactured. All bearings and races are different they should all be a matched set. I was always told to run the nut up by hand. Tighten the nut while turning the rotor until you get a slight resistance then turn nut back off to first spot where cotter pin will line up. This should give you a small load on bearing yet turn easily.

 

This is the process as described in the CSM. I do have a slight variation, however. Since I always repack the bearings if I have the hub off, I tighten once while turning, back off, then tighten again per above. This way I make sure that I'm not getting a false resistance due to grease.