Great response..thank you Noel and Bill; “Wheel - end threads” still not really clear wording---- but assume he means it sheared at the nut holding the brake drum, (end threads on the axle taper ) so the axle itself did not break off,---the retaining nut holding the brake drum apparently sheared at the axle threads?? That lets brake drum walk off. That makes a lot more sense.
>From an engineering perspective fatigue failure is caused by bending back and forth like when you break a paper clip. Scratches or sharp cuts accentuate that (like a notched –by- wire- cutter paper clip, then bent back and forth, snaps at notch. ) The threads on any bolt will act like a stress increasing notch , allowed for in the design, but the drum or whatever is clamped (like a connecting rod cap) must never move on the taper/under the nut . If moving it will load the nut and washer there back and forth wiggling and reversing the load as wheel turns . So several possibilities, the taper in the brake drum was too loose, the nut was under tightened /loose allowing movement , or grossly over tightened and thus half broken at assembly, leading to what happened rapidly. Location of key on the taper and fully seated plays into this issue too…if sitting on key wrong , key placed wrong or key had a chip , burr, dirt etc and tightened it on top of a burr could have loosened up . So almost for sure something was wrong on this car ---with brake drum, key, or fit of drum to axle (why it happened again) .
It also fits with brakes not working right, if drum was slightly off center they would have vibrated a lot as drum would start moving…
Great news for us, basic axle did not “snap” at all , if above interpretation correct ; be sure your drum is seated correctly on key and use FSM torque and torque wrench.
From: Chrysler300@xxxxxxxxxxxxxxx [mailto:Chrysler300@xxxxxxxxxxxxxxx] On Behalf Of Noel Hastalis cpaviper@xxxxxxxxxxx [Chrysler300]
Sent: Friday, January 13, 2017 10:14 AM
To: Chrysler300ClubInternational
Subject: [Chrysler300] Fwd: 300-G and its broken axle
Here's Bill Hall's response re the 300-G's broken rear axle on "The Drive Home II" -
Noel
Begin forwarded message:
From: williamhall@xxxxxxxxxxxxxxxxxxxxxxx
Date: January 13, 2017 at 8:12:24 AM CST
To: "Noel Hastalis" <cpaviper@xxxxxxxxxxx>
Subject: Re: Fwd: 300-G and its broken axle
Hi Noel,
First thanks again to you and the guys in the 300 Club for your enthusiasm and help with The Drive Home Chrysler. The breakdowns will be forgotten, but the memories will remain of the fellowship we encountered during the challenges on the road.
I understand the curiosity and wish I had more information.All this information is secondhand to me but I will tell you what I know.
The breakdown was actually the second axle, same side, that was replaced within 2000 miles. They had to do the same thing over the summer when they found the axle broken at the wheel-end threads. How the wheel did not fall off then, I have no idea. Unfortunately the details were relayed to me by some non-technical people.
So of course when I saw the car again this year prior to Woodward Drive I was curious and was able to speak with the hands-on mechanic. He said that the axle sheared, again at the threads. I wish he had taken pictures but he didn't. Since I found it odd that this would happen twice, I asked if there was some sort of interference in the carrier that might have cut through the axle, but he found none.
Possibly the axle nut was over-tightened. Undoubtedly this is a stressed area on any (used) axle. Some of the blog commentators have seemed to indicate this is an endemic problem with the original rear ends? We are curious to hear what ideas the Club might come up with.
We don't want to point any fingers, we are just glad that no one was injured, the car was not damaged (albeit a very slight bend in the inner rear fender lip and a ground-down brake backing plate- amazing) and we were able to continue. The car drives better than ever now. Rear brakes are property adjusted, etc.
I wish I had a close-up photo. Included is one you can use for the Club. We were in survival mode on the side of the highway and despite our filmmaker Facebook-live streaming the whole thing (he was the driver at the time), the rest of us were just trying to stay out of traffic and get on to our next stop.
The car will be retired, back to the America's Car Museum, still wearing its sponsor livery and all the great memories we have created with the car. I hope, and I believe, that we have raised awareness of these great cars among the collector community. It was undoubtedly the most iconic of the three iconic cars we drove. A TV reporter in Brooklyn interviewing me (in reference to the car) asked "So, whats it like being the hottest girl in the nightclub?" It elicited that kind of reaction everywhere we went. And it was strangely emotional to see the car again after we were reunited with it.
I'll be pushing buttons in my sleep for awhile, and hope to see all the great guys in the 300 Club soon. True friends made possible through this great car!
Best,
Bill Hall
---------------------------- Original Message ----------------------------
Subject: Fwd: 300-G and its broken axle
From: "Noel Hastalis" <cpaviper@xxxxxxxxxxx>
Date: Thu, January 12, 2017 11:48 pm
To: williamhall@xxxxxxxxxxxxxxxxxxxxxxx
> Hi Bill,
> Your commentary and photo of the 300-G with its broken rear axle has stirred some inquisitiveness and commentary within our Club.
>
> Was an autopsy performed on the failed axle to determine the cause of its failure? We'd like to know the circumstances around what exactly happened with it. Any close-up photos?
>
> We welcome your input!
>
> Noell
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