Wheel Bolt Breakage

[jamie1234]

Hi, just been tightening the wheel botls on my fiat punto and ive managed to break one inside the hub

Anyone have any ideas how to remove the bolt? I cant use pliers because where the bolt has actually broke does not extend past the hub.

Is it safe to run with just three out of four wheel bolts for the time being?

Thanks in advance

J

[HiRich]

Best chance to remove it is with a thread extractor set:
Drill hole down the centre of the bolt.
Use the tap to cut a thread (left-handed) which will eventualy release and remove the stub.
You can get an extraction set from any decent motorfactor/engineering hardware store, even some Halfords. Not expensive, and worth having in your kit.
An alternative might be to tack weld a bar to the protrudung stub and lever it off.

Is it safe?
No. You should not drive as you are stessing the others. At most, only a few miles, slowly, and unladen.
Wheel bolts and studs are tricky little b*****s, stressed and case hardened. The crack was probably started by over-torquing (or possibly from being loose and bending). Others may already be failing. Buy a complete new set (at least for one wheel). To see whether any others are failing (and because some ape has over-torqued at least one, the odds are high that others have been damaged), stick the head of each one in a vice and tap the end with a hammer or spanner. You are looking for a 'ring', rather like tapping a wine glass. If one sounds flatter than the others, it is already cracked and should be replaced. I recommend you do all four corners, unless you like the idea of it happening again.

And to finish the job properly, when you refit the wheels:
- Wipe the cup and cone of bolt and wheel to remove any grit (this can cause it to lose grip, and lead to failure).
- Use a torque wrench, and follow handbook guidelines
- After some use (20 miles?), recheck the torque

[jamie1234]

Many Thanks,

Managed to get the stub out by drilling a hole and then used a chilsel to get some purchase on it. It was the locking bolt that broke, seems to be of poor quality material so may invest in some new ones all round. And a torque wrench!

Only a 1.2 punto so not much stress going through wheels so the bolts (of better quality) should be all ok.

Just my other enthusiasm with the tightening!

Thanks again

J

[Chris Y]

Not exactly 'Racing Technology', so I'll move this to the Road Car forum.