overtight axle nuts

Hello everybody !
I'm really a newbie ! I checked again and realised that the axle was ok ! It was only the nut that was damaged ! I also discovered that the axle had been already modified in the past because it's a ø9/16. I realised that when I tried to put a new axle nut from original parts from the vendors ... So now, it could be easy to fix ! What i need is a 9/16 nut UNF but, in France and in french we say "ça se trouve pas sous le sabot d'un cheval" (can't be find under a horse's hoof") which meens you can't find it easily at the retail store but i'll find it. Thanks again to everybody.
 
They make inserts for threads in holes that have been damaged. I wonder if the opposite part is available. I guess you could make one on a lathe. I would have to be silver soldered onto the axle or perhaps glued on with one of the super adhesives. Perhaps you could adapt one that was make for the threaded hole
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. Tractor Suppliers have what is called a Locking Clamp Nut. I keep one in each of my cars in case of axle problem on tours. It will get you or a friend home. Works on the principal of a collet with external threads. Smith and Jones also sells them.
 
Tightening the axle nut increases the tension stress in the axle shaft. The inboard end of the key-way slot is a stress concentration place and a fatigue hot spot. So tightening the axle nut unnecessarily to a high torque raises the tension stress and will lead to this prematurely:
 

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  • Rear Axle Fatigue Failure 184kb.jpg
    Rear Axle Fatigue Failure 184kb.jpg
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I'm fascinated with all the back and forth of opinion on what tension the rear axle nuts should have. After doing some checking of the Ford factory published service manuals and service bulletins I happened to have on hand, none of them even mention what torque value rear axles nuts should have. The BIG question is...what did FORD MOTOR CO. say they should be? If anyone has any factory data I'd like to know myself!! :)
 
Bob Bidonde said:
Tightening the axle nut increases the tension stress in the axle shaft. The inboard end of the key-way slot is a stress concentration place and a fatigue hot spot. So tightening the axle nut unnecessarily to a high torque raises the tension stress and will lead to this prematurely:
Click to expand...

That picture shows the very place a rear axle will break and it is not only the end of the keyway that causes it to be so. Worn rear bearings will result in a broken axle. The hubs always wears more at the outer end, allowing the wheel to want to lean inwards. That put a slight bend in the axle and as it turns, the metal fatigues till it breaks. The tension on the axle nut IMO, has nothing to do with it. Ford didn't even use a torque wrench when they assembled these cars. I don't know why people these days get so obsessed with torque settings.
 
Yes it is less about how tight the nut is and more about that the hub is tight... to the laymen that is a mindblower.
 
I’m ashamed to say how tight I torqued one of my axle nuts, let’s just say over 150lbs. I was really lucky I didn’t strip anything. I knew I was putting a lot of muscle into it and was even thinking “why this much”. I either looked in the les andrews book or got the value on a google search. Spoke to an old model A friend and he was like that’s waaaaaaayyyyy too much. It’s all common sense AFTER you get your mind wrapped around the entire picture. This has been a great and enlightening thread.
 
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