TR2/3/3A Securing new brake disc to the front hub?

[karls59tr]

Is there a specified torque value for the 9/16 bolts that fasten the brake disc to the front hub?

 

[bobhustead]

Torque specifications and torque wrenches serve two purposes and answer two questions. In the application you ask about, the question is "is THIS bolt tight enough to hold what it is supposed to without overstressing the bolt or the items being bolted?" You can find ASTM charts of torque values for various grades, diameters, lubricity and thread pitches of bolts on Google. The second question, applicable to head gaskets and the like is "are THESE bolts tight enough to hold what is supposed to be held and are the pressures applied by the bolts the same throughout the field?"
So, for your application, just look at the charts for the grades marked on the bolt heads.
Bob.

 

[bobhustead]

When you use the torque charts, by the way, it is the bolt diameter, not head size, that counts. I do not know which you used in your post and do not recall the size of the subject bolts.
Bob

 

[LionelJrudd]

The bolts that hold the rotor to the hub are three eigths UNF and the service manuals for both the TR3 and TR 4 state a tension of 32 - 35 foot pound.

 

[CJD]

Those are screws, and are actually redundant. Once the wheel lugs are tightened the rotor isn't going anywhere. As long as you snug them you're good.