BMW R1200R R1150R/T F800 K1200R R1100R/T R1250R RnineT Message Board

bang,
The shop manual says and I quote:
"Do not oil or grease wheel studs!"

Yes, with an exclamation point at the end. The reason why is that any grease or liquid will lubricate the threads will greatly alter the normal drag the torque value is chosen for. This means that as you tighten the studs you will end up overtightening them by a significant amount. Notice the stretched out bolt on the right in this pic:



Clean & Dry threads ONLY!!!!
If the studs are clean, dry and properly torqued, they WILL NOT COME LOOSE!!!!



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I clearly see your point. Thanks cycleRob!

After being politely re-educated by Boxermania's field expertise in (wrongfully lubed) threads relating to bolt torque, the pic in my post above has changed in the interest of accuracy. Thanks AL.


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CycleRob......you have to stop being nice to me.....I don't like it a bit and is causing me a great deal of embarrasement.

My guess is that those bolts are, because of their critical nature, at least metric class 10.9 with a tensile and yield of 151K psi and 136K psi respectively or the equivalent of a US Grade 8 bolt, which is a very good quality bolt.

What is fascinating about fasteners is that torque in reality is a misnomer since the objective is to attain suficient stretch of the bolt to keep the joint tight. Interestingly enough, upon tightening, the material will continue to stretch until it breaks. What you have so kindly shown is when the "elasticity" or yield of the bolt has been exceeded.

PS. The above is not for your edification since you know it very well...I have included such for those that would enjoy knowing a little bit more about what goes into their bikes....you old geezer you.....I love Hilary