I have managed to cross-thread one of the lug-bolt holes. Yeah, I'm an idiot, what can I say? I realized my mistake the instant it happened, so it's probably less than a whole turn that's cross-threaded.
I'm not sure how easy it is (or even if it's possible)to approach the hole from the back and re-tap the thread but that would be my preference if it's doable. Any other options or advice please?
Jon
I'm not familiar with the E46 in particular, but I'd be surprised if there is enough clearance to tap the hub from the rear without removing it first. Though you might just succeed if you canibalise the tap. Even to the extent of cutting it down to just a small stub, with a pair of flats for a spanner.
If you're very careful though, making sure the tap is absolutely square. (use a small square or something fabricated to constantly check) you may be able to pick the original thread up from the front. That would be my first option.
Failing all those, a final option, without hub removal, would be to drill it out and fit a 'Helicoil' thread insert. Make sure it is a genuine Armstrong Helicoil. Not one of the many thread inserts made by other Co's, that IMO are just nowhere near as good. Mike.
And the rest.
Get a magnifying glass and have a close look.
Use suitable tools (e.g. wood chisel - sacrificed) to try and put the original threads back in position. Remove any that are mashed.
In principle you should then be able to use a tap (or a Hilti bolt the right size) to refurbish the thread. As the thread starts gradually on the tap you should be able to get it started very easily and once going push any bent squashed bits back into position (albeit a bit weaker).
If the tap jams (e.g. to trapped pieces of loose thread) remove it, remove any impediments and start again.
Have another look and remove any loose bits of thread etc.
Finally refit your bolt - but line it up properly first this time!
Unless the threaded section is very thin your should be OK.
And the rest.
Get a magnifying glass and have a close look.
Use suitable tools (e.g. wood chisel - sacrificed) to try and put the original threads back in position. Remove any that are mashed.
In principle you should then be able to use a tap (or a Hilti bolt the right size) to refurbish the thread. As the thread starts gradually on the tap you should be able to get it started very easily and once going push any bent squashed bits back into position (albet a bit weaker).
If the tap jams (e.g. to trapped pieces of loose thread) remove it, remove any impedements and start again.
Have another look and remove any loose bits of thread etc.
Finally refit your bolt - but line it up properly first this time!
Unless the threaded section is very thin your should be OK.
And the rest.
Get a magnifying glass and have a close look.
Use suitable tools (e.g. wood chisel - sacrificed) to try and put the original threads back in position. Remove any that are mashed.
In principle you should then be able to use a tap (or a Hilti bolt the right size) to refurbish the thread. As the thread starts gradually on the tap you should be able to get it started very easily and once going push any bent squashed bits back into position (albeit a bit weaker).
If the tap jams (e.g. to trapped pieces of loose thread) remove it, remove any impediments and start again.
Have another look and remove any loose bits of thread etc.
Finally refit your bolt - but line it up properly first this time!
Unless the threaded section is very thin your should be OK.
Usually, you can simply use a tap to repair the threads. The tap is tapered, so it should thread past the screw-up area and become properly aligned so that the thread cutting portion of the tap can do its thing.
Why on *earth* you would go to all this trouble to fix a problem that really should be properly repaired, either with a replacement part or a properly done Helicoil, beats the brown stuff out of me. But hey! Maybe that's just me.
Wood chisels to bend and chop wheel bolt threads back into shape. Recuses self from further discussion.
Thanks very much for the advice given in response to my original post. I considered the various suggestions and concluded that the easiest and cheapest thing to try first was to try to re-tap the damaged threads, so out I went to get the proper tap (12mm x 1.50)this morning. Cost $5.
Luckily, I was right in my initial impression that very little of the thread had been damaged once I had done a magnified inspection of the hole, so I offered-up the tap to the hole and started to turn, applying firm pressure, and the thread recut easily and quickly.
Lug-bolt reinstalled.
Thanks again for the advice!
Jon
Have you priced a BMW hub assembly lately? Do you know how much work it is to get one apart? The guy fixed it for the princely sum of $5 plus about 15 minutes' work he did himself. Not all of us are made out of money and, even if we were, there's no reason *not* to perform such a simple procedure on our own cars - unless it cuts very deeply into daytrading time.
-- C.R. Krieger (Been there; done that)
chuckle...
Yeah, me too. I read somewhere that you can use an adze to hone cylinder bores. Anyone want to try that?
What specifically is improper about the repair?
Nothing at all, if you think that it's OK to bend damaged wheel bolt threads back into alignment with wood chisels then fine. Me? I'd use the big ol' screwdriver that I use mostly as a pry bar. My wood chisels are too precious to use for something like that.
Is *that* what your beef was? In that case, I apologize. Frankly, as someone who definitely does *not* get along with wood, I never noticed that discrepancy in the suggested procedure. I agree I would probably not use a wood chisel to do this, except that in my case, it's because I probably wouldn't be able to *locate* a wood chisel. However, if I found the right one (the 1/4" would be almost an ideal size), you'd be cringing at what happens next ...
-- C.R. Krieger (Been wrong before)
Well, not just abusing wood chisels. I also think that bending and bodging threads - especially important ones like wheel mounting bolt holes - is unwise. I was kind of being sarcastic about my big ol' screwdriver pry bar.
Heck, I just figured your hand-eye coordination was maybe better than most.
As for the relative importance of wheel bolt holes, I suspect we'd disagree on that. For starters, the guy said it was less than a full turn of the bolt. That's not much compared to the full four or five the bolt takes to seat it. Second, there's a *reason* they use five bolts on those wheels. If you've never found a single one loose when you checked them, then you're either anal retentive about checking them or you're unusually lucky. One could easily sneak up on the 'off side' of your car, remove a wheel bolt, and you'd not notice it until you looked.
-- C.R. Krieger (Been there; drove that)
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