Broken axle stud. Anyone else ever had this happen?

[boertje]

2 years ago, I had to repair an oil leak on the 02M input shaft in my 01 bug. Since then I have put 20K miles on the car and all was great. Then yesterday as I was pulling out of the fuel station I heard a big "POP" and looked to see a hub cap lying there. I did a u-turn back into the parking lot to see what I had run over only to discover that it was my hub cap. I picked it up and put it back on my front wheel. Then I saw the axle nut with the axle stud on the pavement. I pulled the cover off and found that it was my axle nut that broke which blew off my hub cap. Lucky for me I wasnt in the heart of Nevada somewhere but just 5 miles from home so I managed to limp home without the axle coming loose or out.
I installed this axle as per specs and torque specs so it rather amazed me. Anybody else ever had this happen?

 

[jettawreck]

New OEM axle or an aftermarket new/rebuilt??

 

[Gotrek]

If it was me at the shop I would judge that the nut was over torqued which caused stretch on the axle and failure. But if it was torqued correctly then that is weird Most car manufacturers either pin or stake the axle nut to prevent it from doing so if it fails/strips threads etc.

 

[boertje]

That was an OEM axle that came from the UK in one of RyanP's kits. I've re-torgued it twice. Once on the first install (I put 75,000 miles on it) and then again when I fixed the trans leak (put about 20,000 miles on it). Who knows how many times it had been loosened and re-torqued prior to me before that. As per bentley - torque the axle nut at the hub to 200Nm/148ft-lb and then loosen 1/2 turn. Roll the car 1/2 rotation of the wheel and tighten to 50Nm/37ft-lb plus 1/6 of a turn. I've done this many times.

 

[Gotrek]

If they add 1/6 of a turn after the final torque sequence that tells me they are expecting some stretch on the axle shaft/splined area. This would make the axle shaft a torque to yield one time use piece

But again that's just me I'm no expert and there is no way I'd replace my axles everytime I took off the nut. I've torque me axle nuts on all my cars dozens of times over the years But do find it strange they don't stake/pin these nuts.

 

[JB05]

Section 40 in my Bentley manual describes the axle nut as self locking and always replace. Did you reuse this nut?

 

[UhOh]

Section 40 in my Bentley manual describes the axle nut as self locking and always replace. Did you reuse this nut?

I wouldn't think that's an issue, as I'm pretty certain that it would be the nut that would be seeing the compromise, not the shaft itself (and behind the nut). Maybe look at the broken segment to see if the threads on either the nut or the shaft look stained? Maybe there's side shock-loading: too loose or too tight might be able to pop the shaft like that?

Any other front-end/suspension issues?

 

[boertje]

The break was well behind the nut (about 1/2") and I see no signs of stretching. I believe that was a new OEM nut as well. There are no threads on the segment where it broke. Just machining markings. Tomorrow the axle comes out so maybe that will yield a clue and I'll have a chance to inspect the suspension for other issues. Up to then, the suspension felt normal. At the time it broke, I was turning out of the fuel station parking lot turning right going maybe 1-3 mph and pavement was smooth with no curb gutter.
I have a used OEM axle with bad inner joint but good outer joint so I can make one good axle from two junks.

 

[Alchemist]

I think that wheel bearing took a beating on the trip home. Bentley says not to move the car until the axle nut is torqued because of bearing damage. A new bearing is still probably better than a tow, so I say a good call on your part.

 

[A5INKY]

ANYTHING can fail. Most 6 speed swaps use used OE axles, and there is certainly nothing wrong with that. However, no telling what the part experienced in it's previous life. I've never seen that happen, but I'm sure it is not the first time in the history of that axle/hub design.

As already mentioned, your wheel bearing is now shot on that side and will have to be replaced with the CV joint.

 

[Gotrek]

Pfft Just weld it on(or JB weld?) and in Russia it will probably last another 200 000km

Comment above was a joke Don't listen to it, just laugh

 

[boertje]

Pfft Just weld it on(or JB weld?) and in Russia it will probably last another 200 000km

Comment above was a joke Don't listen to it, just laugh

Wonder if the quick set JB weld will work?

ANYTHING can fail. Most 6 speed swaps use used OE axles, and there is certainly nothing wrong with that. However, no telling what the part experienced in it's previous life. I've never seen that happen, but I'm sure it is not the first time in the history of that axle/hub design.

As already mentioned, your wheel bearing is now shot on that side and will have to be replaced with the CV joint.

I think that wheel bearing took a beating on the trip home. Bentley says not to move the car until the axle nut is torqued because of bearing damage. A new bearing is still probably better than a tow, so I say a good call on your part.

Yeah I'll know more when I get it apart. Interestingly, that axle is still tight and in place despite the broken piece.

 

[Gotrek]

It should not come out even without the nut unless you lost a big chunk of the end. They fit in tight there isn't much room for them to wiggle out.

 

[boertje]

Got it up on stands. The bearing is definitely done. Got the axle out as well and we'll post a picture later on today.

 

[Wankel7]

Wild!

If you didn't use a new nut and applied the torque to yield procedure when reinstalling the used nut I would guess that could lead to excessive over torquing?

And I would also guess that wheel bear is cooked.

 

[RacerTodd]

If you didn't use a new nut and applied the torque to yield procedure when reinstalling the used nut I would guess that could lead to excessive over torquing?

Re-using the nut shouldn't result in any over-torquing. Oiling the threads will result in more stretch for a given torque wrench setting.

In my early days of working on cars, I reused an axle nut. All that happens is the nut loosens up after a while, destroying the wheel bearing.

Mostly likely, it's just a random flaw in the metal. Not every CV joint is Mangafluxed or crack tested, at most they test 1 in a few hundred. You get a microscopic flaw and with the high stresses on a part like that eventually it fails.

 

[boertje]

On disassembly, the bearing actually looked pretty good which surprised me. Even the nut I was easily able to pull off the broken piece and its threads looked fine. Got a kit from Napa that had bearing snap ring and 12 point axle nut and a few misc nuts for 62 bux. Used the harbor freight kit 66829 to pull out the bearing and install new bearing and hub. Worked like a charm.

The messy part was taking two bad axles and making one good one. One had a bad inner joint and one had a broken outer joint.

So far all is well again.

 

[turbocharged798]

I would bet a few dollars that the torque spec in Bentley is wrong. Seemed very high to me. Bentley is known for typo errors like that, like they list the EHU transmission having gasser gearing. Looks to me like the axle stretched from over torquing until it gave way.

I always use the nice and tight torque method. (breaker bar and give it a nice snug.). Never had an issue.

 

[boertje]

Spoke with Marty at Raxles about this and he has seen this once before and his reason was actually under torque. From their site for the VW MKIV "30 mm Axle nut, tight as possible until axle nut does not turn anymore. If you have an impact gun its easy if you are using a ratchet, move up to a breaker bar and turn till it stops! Just don’t strip anything or that will cost you even more money!! You should have about 4-5 threads exposed once you are tight. If you read the Bentley Manual it gives Very Good instructions on how to tighten the 30 mm axle nut. Unfortunately most of us can’t do it the way the Bentley describes, the way I am suggesting is the way a VW Tech suggested it be done."

I tried to create one good axle from two bad ones but the outer joint of the other is worn out as well so not usable over the long haul. Both axles going to raxles for restoration. Not going Chinesium.

 

[alphaseinor]

I've had that happen on one customer's car, it was on the drivers side, 5 speed, but was a cheap chinesium axle, plus he jumps his car at every railroad track...

 

[1854sailor]

...plus he jumps his car at every railroad track...

Ouch!

 

[ultrasparc]

Must be the season, read this thread and it happened to me. Changed the wheel bearing about a year ago, maybe 15 - 20K miles. It very well could have been over torqued, but doubtfully under.


I have read a lot of people have issues with re-manufactured axles, Especially since this is the left side (long). I am willing to rebuild the axle if I could get the outside shaft. Bora parts has a reman for about $100 idparts has new for about $380.

 

[boertje]

I sent my left shafts for 6 speed trans (had two that needed to be rebuilt) to raxles to be done with proper parts to get OEM quality. He does not have exchange for axles on the 02M so must send in your old ones. If you are dealing with a five speed, just get the parts from bora and do it yourself or go with raxles if you want it done right. The 02M 6 speed is a different story where the only reasonable priced OEM option is parts from Europe or raxles and neither was cheap. Don't want chinesium for something like this. Going to get a spare OEM set from ryanp in the UK just to have it on hand.

 

[ultrasparc]

I sent my left shafts for 6 speed trans (had two that needed to be rebuilt) to raxles to be done with proper parts to get OEM quality. He does not have exchange for axles on the 02M so must send in your old ones. If you are dealing with a five speed, just get the parts from bora and do it yourself or go with raxles if you want it done right. The 02M 6 speed is a different story where the only reasonable priced OEM option is parts from Europe or raxles and neither was cheap. Don't want chinesium for something like this. Going to get a spare OEM set from ryanp in the UK just to have it on hand.

Thanks!

I didn't realize boraparts sold just the outer joint, that's the route I will go.

I do have the 02j.