<VV> axle breakage

[Dale Dewald]

Hello Warren,

Based on my education in metallurgy I would have to agree 100% with Dan 
T.  Do not under any circumstances do any welding on your replacement 
axle/flange.  Instead, find a pair (to replace the axle on the other side 
of the car) of low mileage axles and have them shot peened.  However, 
before shot peening you might also consider using a Dremel tool and a 
fine-grit stone to radius all of the factory drilled hole edges and the 
flange to shaft transition area.  It may be prudent to Magneflux the parts 
before spending a lot of time on them, but I would expect that low mileage 
OEM axles will not have any detectable cracks.  Use the replacement shot 
peened axles for 10 years, then have them either Magnefluxed on some 
periodic schedule or simply replace them with another prepared set.

Dale Dewald
Hancock, MI

At 12:00 10/18/2010 -0400, you wrote:

>I appears that the fatigue started around the factory hole for
>clearance for a socket to reach the bearing retaining nuts.
>     It's only fair to say that this hub has been raced on for 20 some
>years and abused with huge sticky tires and high cornering loads.   No
>fear of failures for daily drivers.

and earlier:

>The axle broke at the junction of the flange holding the wheel studs
>and the stub axle; no bearings or splines involved. The wheel stayed
>on the car due to having disc brakes. The wide wheel is back space
>centered on the flange.
>The plan is to prepare another hub by adding metal in the attachment
>radius by Tig welding.
>Maybe it will last another 45 years if I stay earth bound.
>
>Warren

Then Dan T wrote:

>sounds pretty likely like bending loads from cornering causing fatigue.
>Do you have the pieces? They would be helpful to identify if the
>crack(s) originated from a rough, as forged surface, or a corner or
>other feature left from machining. Either way, improved geometry
>(grinding a smooth contour) and shotpeening could net a significant
>fatigue/endurance improvement.
>
>
>The best TIG welding ever done by man is a casting with relatively
>uncontrolled alloying and heat treatment, full of residual stresses and
>lacking the improved grain size and grain flow and other benefits of
>the original forged material.

 >>>snip<<< (references to fatigue and bending strength of welded joints)