Alloy wheel bolt collar failure

[SD and P]

A cautionary note regarding aftermarket wheel bolts.
Having acquired some winter wheels and tyres for my car last year, I set about removing the original wheels that my car was supplied with from the factory. I discovered that all but the 4 locking bolts were non-Porsche bolts with aluminium waisted cap rings - top image in the picture below. Several of the cap rings had fractured. Further, after removing, carefully applying Optimoly TA and retorquing to 130Nm, most of these cap rings shattered completely. I replaced them all with genuine Porsche bolts which have a much harder cap ring. No problems with these, all perfect when I swapped back to 'summer' wheels last week.

I'm still racking my brains as to why the original owner would have swapped out all the bolts for the cheap and nasty replacements.

[mohitos]

Yet another Pork Chop quality product ?

[Magic919]

Do they still torque those to 130? I thought later Cayman increased to 160.

[Pvapour]

SD and P said:

I'm still racking my brains as to why the original owner would have swapped out all the bolts for the cheap and nasty replacements.

I'd wager aftermarket wheels were fitted at some point & when originals were re-fitted the original bolts were long gone so the aftermarket ones were retained, maybe.

[SilverPorker]

Or the original bolts showed signs of cosmetic corrosion/rust and the original owner baulked at the price of replacing them with Porsche OE bolts (£160 I think) particularly as the new ones will probably do the same after a few years. Seems like a false economy in hindsight. My original bolts have spots of rust on them, but nothing that a touch up with paint wont remedy.

[SD and P]

mohitos said:

Yet another Pork Chop quality product ?

Probably - that was where I found the photo and realised they weren't OEM.