Hub failure on track (USA)

mazmad · Postby **mazmad** » Wed May 08, 2013 9:03 am

They have declared National Hub Awareness Month.

Watch it to the end, the wheel ends up in view of the rear vision mirror.

http://www.youtube.com/watch?v=vhQ-ueUmDJQ&feature=share&list=UU4aUrHmJ7dmnxwUy-YqY-Dg

It is from miata.net http://forum.miata.net/vb/showthread.php?t=499956

Check your hubs people!

manga_blue · Postby **manga_blue** » Wed May 08, 2013 7:08 pm

Slightly disturbing but a good warning nevertheless. I found SMP South really hard on the car over the weekend, bouncing off curbs and ripple strips on entry, apex and exit of almost every turn. Bearings a bit noisy on the way home ... :evil:

mazmad · Postby **mazmad** » Wed May 08, 2013 9:46 pm

So how do you check hubs Phil?

Postby **NitroDann** » Wed May 08, 2013 9:52 pm

Inspect the front AND rear faces of the hubs for hairline cracks similar to checking brake disks.

Dann

manga_blue · Postby **manga_blue** » Wed May 08, 2013 11:40 pm

Before this thread I was just going to do the usual bearing check. Jack it up. Wheels on: check hub for play up/down and forward/back. Wheels off, discs lightly bolted back to hubs, pads pulled off discs: rotate and listen/feel for bearing noise. Wouldn't be the first time bearings were replaced on this car. It's done over 60 track days.

Now I'll try doing what Dann said. Would be nice to see photos of a hub before catastrophic failure so I'd have a better idea of what to look for. All we have to go on atm is "If you spend a fair bit of time on the track, we strongly recommend you check your rear hubs for cracking on the inside." from FlyinMiata.

manga_blue · Postby **manga_blue** » Wed May 08, 2013 11:41 pm

uh oh! This sort of failure is not going to be making any noise first.

manga_blue · Postby **manga_blue** » Wed May 08, 2013 11:55 pm

from 2006:
http://forum.specmiata.com/cgi-bin/ulti ... 002215;p=0

mazmad · Postby **mazmad** » Thu May 09, 2013 8:14 am

So these two parts are supposed to be bonded and have let go? Is that yours or from the miata site?

manga_blue · Postby **manga_blue** » Thu May 09, 2013 9:49 am

mazmad wrote:So these two parts are supposed to be bonded and have let go? Is that yours or from the miata site?

No, It's not mine. :beer:

The photo above is one that FlyinMiata have posted on their blog and Facebook. The hub on the left is a whole undamaged aftermarket one. The hub on the right is the flange part of a broken hub. It's the part that stayed with the wheel after an incident like the one in the video. I'm not sure whether the broken one is OEM or aftermarket but it's not really important because both OEM and aftermarket hubs have been involved in these failures over the years.

The broken flange is the other half of this hub, or at least one like it:

If these are developing cracks on both inside and outside faces then it looks like you may have to remove the hub to inspect it properly. In which case it becomes a normal element of the preventive maintenance regime of a regular track car.

mazmad · Postby **mazmad** » Thu May 09, 2013 12:02 pm

That bottom picture, ouch.

Right. Added to the check list (and will raise it with the workshop too to make sure they are also).

Sailor · Postby **Sailor** » Thu May 09, 2013 6:16 pm

Dye penetrants are the way to get best results.
This will reveal cracks clearly that are very hard to pick with the naked eye.
Various types are available from many auto suppliers.
Just clean. spray on, leave, wipe and look for the crack.

manga_blue · Postby **manga_blue** » Thu May 09, 2013 10:00 pm

Sailor wrote:Dye penetrants are the way to get best results.
This will reveal cracks clearly that are very hard to pick with the naked eye.
Various types are available from many auto suppliers.
Just clean. spray on, leave, wipe and look for the crack.

Thanks Rob, will look into that.

Gotta love this from the big forum today.