My nuts sheared off

[pugslyyy]

On my recent 6200 mile trip, this happened about 600 miles from home. I drove the rest of the way back while keeping an eye on the other studs. I could see that they were all slowly torquing round - but fortunately everything held together for the remainder of the return trip.


I finally pulled together the repair parts I think I'll need - 6 studs, 6 lug nuts, 6 crimp nuts (for the inboard side of the stud). I was very surprised by the cost, less than $100 for everything.

Today with a fresh 20lb CO2 tank and my mighty 3/4" impact I started to pull the hub apart. I thought that it would come apart a lot easier than it did. Here's what the result is -



My biggest current issue is this spinning stud. I can't pull the wheel off with it still on. Any thoughts on how to remove? Also, any thoughts on what the heck is going on here?

 

[Haf-E]

You might be able to cut a straight screwdriver slot into the end of the bolt with a dremel and a small cutting disk - they perhaps use a impact screwdriver if the bolt is stubborn while holding the lug nut with a box wrench or something...

Seems like a very strange problem going on - are these aftermarket single type wheels?

 

[dhackney]

I can't recall the details on how that hub assembly goes together.

The first thing to do, as always, is to have a cup of tea or coffee. That's always the rule if the boat isn't sinking.

Next, I'd closely review the service manual pages on that hub and see what challenge(s) you are facing.

The service manual PDF is in the "chassis" directory/folder of all the build files that I gave you for the Fuso.

For the spinning stud:

1. Hold the nut with a big wrench that you can tie off to something
2. Drill a hole big enough and deep enough for a meaningful grade 8 bolt (use a normal right-hand bit as, if anything, it will turn the stud down through the nut)
3. Tap the hole
4. Insert a grade 8 bolt with a lock nut & washer; don't put it all the way down, leave a mm or so
5. Tighten down the lock nut
6. Spray the lug nut / stud thread interface withe WD40 or your favorite alternative; let that soak in for a day or two
7. If you can do so without starting a fire from the penetrating oil, use a plumbing torch and put some even heat around the nut; avoid heating the stud
8. Use a socket and breaker bar on the grade 8 bolt and your big wrench on the nut
9. Remove the nut (notice how quick and easy it was to type those three words... )

If that doesn't work, you'll probably need to torch it off.

 

[gait]

good to get home in one piece.

Do you have a very close up of the fracture face of the stud that broke while driving? Include the bevel round the hole in the wheel.

Can't really see clearly but the one that broke during nut removal looks like the nut was sufficiently seized on the thread and a big load broke the lug. The one that broke while driving will probably have a different fracture face, maybe with a bit of fatigue cracking.

The brown marks in the first photo, radiating from the nuts, are perhaps an indication of something. Maybe some movement between nuts and wheel. Possible things have been loose and moving for a while, though the wheel nut indicators suggest you would have noticed if the nuts were unwinding.

Are there similar radial brown stains on other wheels?

The lugs maybe have raised serrations for where they pass through the hub to limit turning. You;ll see on the new ones. Possibly the lug with the nut that can't be undone has been working in the hub so now rotates freely. Once removed there may be damage to the hole in the hub. May need new hub.

To remove simply drill down the middle of the lug. Successively bigger drill bits until a hammer knocks the nut off. Take care not to damage the wheel. The lug needs replacing anyway.

Alternative is a hydraulic nut splitter. Or a hacksaw cut through the nut, perpendicular to the lug - a cutting wheel would work better but risks damage to wheel.

You'll possibly have the same problem with the crimp nut on the inside.

Once the wheel is off inspect the inner bevel of the holes in the wheel and the surface of the lugs. May or may not help reveal root cause.

Possibly a case for lubrication on the thread during assembly but not the beveled face of the nut onto the wheel.

 

[evilfij]

This is why when anyone gets near my car with an impact gun to put on lug nuts I stop them. Get a proper torque wrench and do it right then check again after going down the road a bit.

I would cut the nut off and be done with it. No way I see that it is actually going to come off.

 

[kerry]

I have more questions than I have advice. Rear wheel or front wheel? When you say that you could see them slowly torquing around, were they getting tighter or getting looser? If they were getting looser, why? That seems to indicate they weren't torqued tight enough. I can't imagine that they were getting tighter, but I guess strange things can happen. (By the way, where did you find the orange indicaters? I tried to put some on my nuts a few years ago but they weren't tight enough to stay on). Are these duals or single? If duals, then isn't the spinning bolt just the inner part of the lug bolt unscrewing from the hub and releasing the inner dual? At this point I'm so unclear as to what is happening that I can't offer useful advice. I can however offer you my sympathies. I think FG lugnuts are a royal PIA. Not sure why the torque values for them are so high.

My best guess at this point is that the spinning stud will require judicious use of an acetylene torch to remove. (or, as I once read in a Craigslist ad, 'settling torch')

By the way, I initially thought you may have engaged in the same kind of spiritual discipline as that well known Church Father, Origen, who also sheared off his nuts.

 

[kerry]

Is that the wheel which had the uber tight inner wheel lug bolts which took you forever to get off?

 

[pugslyyy]

good to get home in one piece.

Do you have a very close up of the fracture face of the stud that broke while driving? Include the bevel round the hole in the wheel.

Can't really see clearly but the one that broke during nut removal looks like the nut was sufficiently seized on the thread and a big load broke the lug. The one that broke while driving will probably have a different fracture face, maybe with a bit of fatigue cracking.

The brown marks in the first photo, radiating from the nuts, are perhaps an indication of something. Maybe some movement between nuts and wheel. Possible things have been loose and moving for a while, though the wheel nut indicators suggest you would have noticed if the nuts were unwinding.

Are there similar radial brown stains on other wheels?

The lugs maybe have raised serrations for where they pass through the hub to limit turning. You;ll see on the new ones. Possibly the lug with the nut that can't be undone has been working in the hub so now rotates freely. Once removed there may be damage to the hole in the hub. May need new hub.

To remove simply drill down the middle of the lug. Successively bigger drill bits until a hammer knocks the nut off. Take care not to damage the wheel. The lug needs replacing anyway.

Alternative is a hydraulic nut splitter. Or a hacksaw cut through the nut, perpendicular to the lug - a cutting wheel would work better but risks damage to wheel.

You'll possibly have the same problem with the crimp nut on the inside.

Once the wheel is off inspect the inner bevel of the holes in the wheel and the surface of the lugs. May or may not help reveal root cause.

Possibly a case for lubrication on the thread during assembly but not the beveled face of the nut onto the wheel.

I'll take some clearer photos but I think the damage was done before I put this wheelset on - it was an incredible PITA to break the lugs loose last time and they are only supposed to torque to 400 ft-lbs, and they were over 2000.

I think I may try drilling out the stud. I don't think there is enough room to get a cutting wheel in there, but I may try that first. Yes, I do plan on replacing all the studs and nuts on this hub - potentially the hub as well.

 

[pugslyyy]

Is that the wheel which had the uber tight inner wheel lug bolts which took you forever to get off?

Yes, this is the corner that I had all the problems with. I haven't checked the other hubs yet, but won't be surprised if it is just an issue only on this hub.

 

[pugslyyy]

This is why when anyone gets near my car with an impact gun to put on lug nuts I stop them. Get a proper torque wrench and do it right then check again after going down the road a bit.

I would cut the nut off and be done with it. No way I see that it is actually going to come off.

Yeah I've got a torque wrench. The previous owner had a new set of tires put on roadside and I'm pretty sure that's where these problems are coming from.

 

[kerry]

Has anyone else run as much weight as this on the single rims/lugs?

 

[pugslyyy]

I have more questions than I have advice. Rear wheel or front wheel? When you say that you could see them slowly torquing around, were they getting tighter or getting looser? If they were getting looser, why? That seems to indicate they weren't torqued tight enough. I can't imagine that they were getting tighter, but I guess strange things can happen. (By the way, where did you find the orange indicaters? I tried to put some on my nuts a few years ago but they weren't tight enough to stay on). Are these duals or single? If duals, then isn't the spinning bolt just the inner part of the lug bolt unscrewing from the hub and releasing the inner dual? At this point I'm so unclear as to what is happening that I can't offer useful advice. I can however offer you my sympathies. I think FG lugnuts are a royal PIA. Not sure why the torque values for them are so high.

My best guess at this point is that the spinning stud will require judicious use of an acetylene torch to remove. (or, as I once read in a Craigslist ad, 'settling torch')

By the way, I initially thought you may have engaged in the same kind of spiritual discipline as that well known Church Father, Origen, who also sheared off his nuts.

This is passenger side right hand thread, so natural motion is to tighten. I use the 41mm torque-light wheel nut indicators http://torque-tight.com/Torque-Tight_.html

I really don't want to use a torch to get the lugs off, that will just cause a whole lot of other issues!

 

[pugslyyy]

Has anyone else run as much weight as this on the single rims/lugs?

I don't have an answer for that, though I do know that the rims/tires are rated higher than the axle now. I really think that the issues were caused before the wheelset change - but still have investigation to do on that!

 

[gait]

are there any of those radiating brown stains on the driver's side?

Quite likely over-tightening caused sufficient damage. Fracture face may help. It doesn't take much once the conditions for starting a crack change.

My Aus passenger side are left hand thread ..... had to think about that!!!!!!

 

[dhackney]

My Aus passenger side are left hand thread ..... had to think about that!!!!!!

Another example of why we need a universal way to refer to the lateral sides of a vehicle. I vote we adopt the nautical "port" and "starboard."