yeah knockback sucks! never noticed any knockback on the s2k tho.

 

Suby knockback

If you aren't expecting it you're screwed, especially given the 4wd stab and steer driving style.

 

yeah scary shit if you aren't expecting it.

Check this knockback:
http://www.034motorsport.com/gallery/d/957...07_practice.wmv

Car is an A4 IIRC.

 

seems like you would want hubs out of tougher and stronger material - not necessarily just harder material.

Given the pattern of failure, since all the failures are essentially at the base of a tab, I would assume that flexing has some contribution to the failure.

I would assume that since the pattern of failure is the same on all of the tabs of the hub, that the failure was not associated with inclusions in the metal.

A stronger material would not flex as much, and a tougher material would withstand more cycles of loading/unloading before failure.

 

Nice footwork.

Could be knockback, could be boiled fluid. I saw a vid a while back of Randy Pobst in a 911 where the fluid was shot late in a race and he was doing a fancy two-step just like that to make sure he had a pedal at the next turn.

 

he told me it was knock back

 

 

Also a good demonstration of heel-toe down shifting.

 

Becareful when over-torquing the axle nut. This can also cause shearing.

There was a time when the recommended fix for the clicking people sometimes hear was re-torquing the axle nut to above factory spec. Not the way to go.

Davepk, nice shot from Sears

Why not just replace the hubs twice a season after XX hours of usage regardless of stress cracks being present It's easier than re-inventing the wheel Obviously this doesn't solve the issue of our weak hubs not taking the stress cycles you subject them to. However, since you know the symptoms and mode of failure, address it pro-actively so it shall no longer trouble you. Much like the valve retainers and upper a-arm tabs...

 

So can any tracker please dye test their hubs and see if there is crack propagation at so many cycles?!