Rear Wheel Nut Torque

google reckons 230Nm

 

848 is 176Nm. 230Nm is for the bigger axle with 55mm bi hex nut...... don't believe everything Google says

 

Correct 848 Rear Axle/wheel Torque Settings | Ducati Forum

 

Beaten to it, ignore mine.

 

You and me both Andy

 

...and don't omit the grease...

 

10 dugga duggas.....

 

ft

 

Over the years (and years) I have applied grease to wheel nut threads, BUT thinking more, does this affect the torque in as much as you (or I) apply too much torque according to the clicking on the torque wrench? In as much as a dry thread would get to the right torque setting sooner.

 

Oooooo; is this going to be as long as exhaust-gate Thread. Vis a vis legal/not legal. Popcorn ordered & lazyboy warmed up(chair)!

 

Further to my many posts about this topic, I'll repeat: The simplified relationship between applied torque and the resulting axial tension is wholly dependent on the friction coefficient between the two materials. Dirt, plating, corrosion, etc all affect this coefficient so the one simple way to obtain a reasonably reliable coefficient is to use oil, grease or thread-locker fluid (thread-lock fluids are designed to have a similar friction coefficient to light oil).
Unless a fixing is measured for actual strain (fractional change in length) on tightening, the torque/force equation is as close as we can get in our workshops and is sufficient.
Just look at the workshop manual - fixings with no oil/grease/whatever specified are not critical ones.

Greasing/oiling a thread does not make it more likely to loosen itself - that is geometrically impossible. Yes - vibration, corrosion, etc can alter the state of a fixing but that's irrelevant when tightening...

I recommend anyone who is actually interested to have a good look at all the information here:

Bolt Science Web Site https://share.google/GRn817tcRdYGjB4cL

 

IS that why, when I torque an axle nut to the correct 250nm, a 450nm impact driver won't undo it next time? I always clean nut and axle thread with penetrating oil but don't apply grease.

 

The service manual quite clearly says grease.

 

Loads of controversy on this one, and as per Keith's link, a massive subject. All i will say is grease next time is a good idea, and recommendation from the factory is the best one.

 

I think heat has a lot to do with it. High torque fasteners are under a lot of torsion before they reach the required torque and that generates heat - albeit not much. But most of us when releasing the nut will do it stone cold. Harirdryer?

 

Spot on, heat definitely an ingredient.

 

Yes. Dry friction is a lot higher than wet/sliding friction.

 

In my opinion, incorrect wheel nut tightening is the reason for the axle recall on later ssa hubs