DangerZone9K

I was there when it happened. He did use the gun.

I went ahead and bought the used axle that I found from craigslist.

Should I just tow the car to Honda? I have all the parts just need to pay for labor... just called Honda and they want around $500 for labor for the axle install.

AE_Racer

Preferably i'd do it myself.. But if you don't have that option, i'd definitely go somewhere else and not let him touch it again.

DangerZone9K

Ok so I'm going to head over to the shop and demand that they give me an axle and pay for towing so I can take it else where.

Will let you guys know.

cosmomiller

If the clowns at your shop were the same ones who installed the nut with a super driver and staked it, they likely over-torqued the the thing leading to the eventual failure. An over torque can lead to failure as has happened to others in this forum and Billman has indicated.

Take it to 180 ft lbs and then 60 degrees past that.

https://www.s2ki.com/s2000/topic/929...__hl__axle+nut

nissanfanatic

I bet they replaced the bearing and reused the hub.

Mine failed and was never overtorqued. It fails if you reuse the worn out hub, as does the wheel bearing.

Every time I have removed an axle nut, it has required a 3/4" heavy impact. I would be more inclined to believe that if they used a typical 1/2" air impact that they would undertorque the nut. None of the impacts I have ever used have had enough force to tighten larger fasteners.

dwight

I'm no metallurgist, but those look like beach marks to me. That means it was a fatigue failure, rather than it was overstressed by the mechanic trying to take it off. If it was fatigue failure, it was likely caused by having an under-torqued nut so you didn't have enough clamping force to maintain joint integrity.

cosmomiller

I have virtually no experience with impact drivers but I do recall the comments by Billman that it is easy for some drivers used in shops to go way over the limits. They are out there.

I would think an over torque would be a cause of fatigue and failure. One guy where I live had one. I did the axle re-tighten DIY and realized after a month or two I must have over torqued the nut. I went back, removed the nuts and set them again; I was worried about fatigue failure jus like this.

windhund116

Believe me, if you use continuous 1200 ft-lbs of torque on this nut --- you are going to cause damage. The excess torque can irreversibly stretch the shaft or bolt. Old school air guns, that max out in the hundreds of ft-lbs seem a lot safer for auto use.

dwight

Under-torquing allows fatigue failures to occur because the joint can separate. If it's properly or even over-torqued, the joint stays clamped so the fastener doesn't see the varying loads.
http://en.wikipedia.org/wiki/Bolted_joint#Failure_modes

I only skimmed this 75 minute-long video so I don't know if it addresses it directly, but a lot of the concepts related to it are explained.
http://www.youtube.com/watch?v=yyCfKLJOFzY

cosmomiller

I think we are actually on the same page, just coming at it from different directions. From your link:

Quote:

"The most common mode of failure is overloading: Operating forces of the application produce loads that exceed the clamp load, causing the joint to loosen over time or fail catastrophically.

Overtorquing might cause failure by damaging the threads and deforming the fastener, though this can happen over a very long time. Undertorquing can cause failures by allowing a joint to come loose, and it may also allow the joint to flex and thus fail under fatigue."

End quote.