This is to satisfy my curiosity….

The handbook of my (59 plate Mk II) Octavia shows a picture of the security wheel bolt thingy. The picture illustrates a male bolt which has a shouldered shank, with the shank having irregular grooves about its circumference. The bolt then slides into the female wheel bolt assuming that the pattern of the grooves matches. The whole thing looks like a piece of straightforward and solid engineering.

However the security wheel bolt supplied with my car looks very different. There are no grooves in the shank and instead there is only a slightly raised male pattern at the end of the bolt. Presumably this engages an equivalent female pattern inside of the actual wheel bolt. But the height of the raised part of the pattern on the security bolt is quite small bearing in mind the likely torque demands.

I asked about this at the dealer and they assured me that what I have is correct although they alluded to having experienced some unspecified “problems†with them. To me, it looks like a piece of poor engineering and an accident waiting to happen. I would suspect that some over-enthusiastic tyre fitter with an air wrench who does not have the security bolt seated properly and fully home could wreck the engagements between security bolt and wheel bolt very easily.

However I cannot see any references to this issue on this forum. So maybe its fine and no problem.

But has anybody experienced any issues with these “patterned†security bolts?

I would suspect that some over-enthusiastic tyre fitter with an air wrench who does not have the security bolt seated properly and fully home could wreck the engagements between security bolt and wheel bolt very easily.

I needed mine replaced after ATS knackered the socket.

Steve

My Octavia (57 MY 2008) has the splined bolt you described which removes the wheel bolt as it goes. There are not many variations on the spline spacing and sothe arrangement isn't that secure in practice.

Yours sounds like it might remove a separate (freely rotating cover) on the wheel bolt which can then be removed by the wheel brace. If that were the case there wouldn't be much torque involved.

You mave have to investigate further by trying to take off a bolt?

Hi Friendlyfire.

Nope the security bolt is designed to turn the wheel bolt directly once inserted.

Steve vRS's reply doesn't surprise me. I would expect the design of this security bolt to result in an easy failure when a ham fisted technician is over enthusiastic with the air wrench.