Do I need a new wheel or a new hub?

I was at the track today and had some brake issues that cut my day short. This was probably for the better as on the way home I started hearing some clunking. At first I thought it was the noise that was coming from brakes, but it gradually got worse and eventually the car started pulling to the left. I pulled to side of freeway and see four of my lug bolts on the ground and the wheel slanted. Turned out the lug bolts somehow jostled free (I torqued the wheel last night and during tech inspection this morning to 88 ft-lbs). There was also a lot of metal flaking on the wheel.

I managed to get the lug bolts back in, got off the highway, and slowly made my way home stopping every few miles to re-torque the bolts since they kept coming loose. Now I have my car apart and noticed that the front wheel bolt seats are no longer circular. I also noticed that the hub lug bolt holes do not quite line up with the brake rotor and looks like the lugs dug into the rotor metal when being screwed in. The lugs themselves also have messed up threads (probably did damage the hub at this point?). The lugs have some surface rust on the ends - would this have caused them to get over-torqued even though I was torquing to 88 ft-lbs? And the hubs are quite rusty too... yay midwest.

So the question is - do I need a new wheel, a new hub, both? This isn't even getting into my iSweep IS2500 brake pads disintegrating after 2 sessions. I came to the track with 7mm on the drivers side and 8mm on the passenger. The drivers side inside is now bare metal in some areas and all four front pads are less then 2mm. Rotors are pretty toast too due to metal on metal.

On a brighter note, I was keeping up with a Porsche GT4 in the corners today (he'ld easily pull on straights).

Let me know if pics of anything else are needed/helpful.

On second inspection it appears the lug bolt threads are only messed up where they met the rotor metal. The piece going into the hub appear to have good threads. So o don't think over torquing was the issue. Could the rust on the hub portion of the lug threads make them loosen up?

In my experience, you must have at a minimum the thickness of the backing plate worth of pad at the start of the day. Otherwise, you fail inspection and are not allowed on the track. Per the organizer (PCA), it is the driver’s responsibility to monitor pad wear during the day. It sounds like you may have been below that threshold.

No idea what caused your other problem.

jmason said:

In my experience, you must have at a minimum the thickness of the backing plate worth of pad at the start of the day. Otherwise, you fail inspection and are not allowed on the track. Per the organizer (PCA), it is the driver’s responsibility to monitor pad wear during the day. It sounds like you may have been below that threshold.

No idea what caused your other problem.

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I was not below the threshold - for the local PCA region it was 50% of pad life left at start of day, which I guess may be pretty close to having the backing plate thickness worth of pad left. Pads started at 12 mm and were at 7-8 mm so more than 50%. I did two track days on these pads previously that wore away the initial 4-5 mm. How did two sessions kill off the same amount/more? Clearly I was monitoring my pads since I noticed this issue.

That's neither here nor there though - the issue is that pads disintegrated, lug bolts came loose damaging the wheel. I know what to do for the pads/rotors, but what about the lug bolts? From what I am reading it's the mating surface between the lug bolt/wheel that actually clamps it down. Since the wheel is damaged, I will need to get the wheel fixed or get a new wheel?

Sounds like the brakes got pretty hot to soften racing pads and loosen lug bolts - well done keeping up with the big dogs in the twisty bits! I'm no metallurgy expert but heat cycling can change the properties of metal and I'm guessing the rotors, calipers and hubs all got a little warmer than OEM parts were designed to get.
I would replace the lug bolts and check to see if the threads on the hub are wallowed out - there is probably some damage since the lug bolts kept working loose. Swap a wheel from another position and see if the issue follows the wheel, but I would be inclined to replace the wheel if the seats are visibly damaged.
My take if it was my car (I get more conservative as I get older!):
Definitely replace:
Pads, rotors & brake fluid
Check all rubber caliper parts: seals, guides bushings & boots for deterioration
Replace both sets of front lug bolts and the damaged wheel (Used Austins are cheap & plentiful on this site)
Clean the hub threads with a tap and check for play with a new lug bolt - compare both fronts and a rear hub (rears don't get quite as hot so more likely to be OK)
Likely:
New Hub
You have the Midwest double whammy of heat and corrosion working against you, and a wheel falling off on the track or street will ruin the rest of your day!

Running with a wheel loose certainly means that wheel is suspect AT BEST. If there's any ovalization of the holes, I'd replace it immediately (the ball seats will also be damaged and not allow for proper tightening (less material contact means higher stress and more deformation). Similarly, the lug bolts are trash.

I'd run a tap through the hub threads to clean them up and inspect. Safe move is to replace, but they may be ok.. 50/50 shot?

Was cleaning the calipers today and turns out the paint itself is bubbled so they definitely got hot! The wheel lug holes are definitely out of round. Fortunately a salvage yard a couple hrs away has a 2017 with 4 wheels available. I may drive out there this week to grab one or two.i cleaned rust off a lug bolt and it threaded nicely so I am hopeful the hub is good. I will clean the rust off, throw a new wheel on, probably get a lug nut conversion set.

Also getting new rotors, pads, and have brake fluid that was waiting to go in after this track day.

Damn, Dybz! Your hubs are more than likely toast. Wheels might be fine, but slop in hub threads is a definite no-no if you want for your shit not to go flying off at the most inopportune time... especially if you're tracking. Do yourself and everyone else a favor and replace the hubs if there is any sloppiness what-so-fuckin-ever in the threads.


While i'm at it, may as well recommend you get Rennline studs. Studs remove hub thread wear from the equation and it's soooooo much easier to change wheels in the paddock with studs vs. bolts.

blunted_brick said:

Damn, Dybz! Your hubs are more than likely toast. Wheels might be fine, but slop in hub threads is a definite no-no if you want for your shit not to go flying off at the most inopportune time... especially if you're tracking. Do yourself and everyone else a favor and replace the hubs if there is any sloppiness what-so-fuckin-ever in the threads.


While i'm at it, may as well recommend you get Rennline studs. Studs remove hub thread wear from the equation and it's soooooo much easier to change wheels in the paddock with studs vs. bolts.

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Wheel is for sure damaged, hub seems fine, but I will keep an eye on it. Getting a stud/nut conversion for sure.

I'd also repkace the hubs and wheel bearings.

always check lug tq after each session is the rule. i have been doing this a long time. i check it before first session/tech. then after first and second session.

food for though. glad everything is not trashed..

beers

The Fed said:

I'd also repkace the hubs and wheel bearings.

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If threads on hub are ok, why? Could they be damaged, but seem to thread ok? I figured if I get the stud/lug nut conversion I would use loctite blue on the hub side of the stud to make sure it won't loosen. Maybe go crazy and loctite epoxy it down.

swoope said:

always check lug tq after each session is the rule. i have been doing this a long time. i check it before first session/tech. then after first and second session.

food for though. glad everything is not trashed..

beers

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Good advice, thanks. Will do that next year! Think I am done for this season.

Dybz said:

If threads on hub are ok, why? Could they be damaged, but seem to thread ok? I figured if I get the stud/lug nut conversion I would use loctite blue on the hub side of the stud to make sure it won't loosen. Maybe go crazy and loctite epoxy it down.


Good advice, thanks. Will do that next year! Think I am done for this season.

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you would need loctite red, not blue

Dybz said:

If threads on hub are ok, why? Could they be damaged, but seem to thread ok? I figured if I get the stud/lug nut conversion I would use loctite blue on the hub side of the stud to make sure it won't loosen. Maybe go crazy and loctite epoxy it down.



Good advice, thanks. Will do that next year! Think I am done for this season.

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hey if you have any other hpde advice please let me know .


it is a huge amount of fun, but the learning curve is steep.

it can be as expensive or as inexpensive as you want.

beers

navindralr said:

you would need loctite red, not blue

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Right, red is the tougher one, thanks.