Pass side axel. Threaded adjuster wheel. How far should this be threaded on to start..? No mention of it in my service manual.... ???

go on the low side, .005"-.010" EDIT Oh OK I see what you are asking, I was thinking of final end play adjustment

so just threaded on a small amount.?

make sure as you bolt the axle in with the 5 bolts, that you are monitoring the end play so it is always loose then with the axle bolted in all the way then adj the threaded adjuster to where you have just a hint of in/out movement on the pass side. Regarding this: The flat flange with the 5 holes always seems to fit tight over the stud bolts so best is to tap it down on the studs using easy hammer taps with a drift opposite each other so it is moved in to position flat & not tilted to one side till you get it seated, THEN install/tighten the nuts and then set the end play. OT dont forget to lube the bearing with a needle attachment to your grease gun and that the inner large seal is in place/installed correctly. EDIT just make sure you have end play (any amt) while the axle/flat flange is being tapped into position against the foam gasket/b plate. e brake horizontle lever MUST be out at this point in time

yes, just a few turns which gives you the most end play to start with

The manual is not going to give you a starting point. Start with it most of the way out and do what the manual says to seat the bearing as you adjust it in.

The more threads exposed on the adjuster wheel, the more end play the axles will have if everything is properly installed. More end play is good when starting the adjusting process.