Author Topic: Hub attachment bolts  (Read 3413 times)

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Spider2

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Hub attachment bolts
« on: 09 June, 2025, 04:43:00 PM »
The siding pillar rally this year was a brilliant event in Northern France but the drive back in my newly commissioned Appia 2 was quite eventful. The car started to veer off to the right under braking and progressively got worse closer to home. I had recently done a lot of work on the front left brake and that was where I suspected the problem was. However, after taking off the drum, everything appeared good, no leaks and the wheel cylinders operating OK. Putting it all back together I noticed there was axial play between the wheel and the drum. A wheel bearing I thought. No, the 8 bolts holding the hub to the drum were loose even though the lock tabs were in place. about 2/3 of a turn was needed on each bolt to tighten them.
Old cars never cease to amaze me.
 

Kevinlincs

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Re: Hub attachment bolts
« Reply #1 on: 09 June, 2025, 07:28:54 PM »
Most likely the cause of the loose bolts was foreign bodies between mating faces, rust or dirt. This gets clamped during assembly then as the parts heat and cool, shimmy against each other this allows the parts to become loose against each other. It's not that the bolts come loose (evidenced by the lock tabs still being in place) it's that the clamping load disappears as the dirt or rust comes out.
To be sure I would take the hub off again and make sure both mating faces are clean and corrosion free.
This is a common issue with wheels that have been fitted without being cleaned, especially the spigot area as it gives a false feeling that clamping loads are reached.
The lock tabs have actually saved you big time as they prevented the bolts winding themselves out and the hub completley detaching!
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Spider2

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Re: Hub attachment bolts
« Reply #2 on: 10 June, 2025, 04:30:42 PM »
Hi Kevin
Thanks for the heads up on the hub bolts. All makes sense. I will do as you say and split the hub from the drum and give both surfaces a good clean Also I think a bit of Loctite on the threads would do no harm. Will do the other side as well.
Cheers
Simon