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A few months ago, I picked up a cheap 2005 4Runner V8 2WD, which had a slight front-end vibration that I wisely ignored until recently.

A week or so ago, I felt a pretty severe thunk from the front LH wheel, followed by another thunk per wheel revolution. I managed to nurse it home. When I jacked it up and removed the wheel center cap, I saw this: Missing Lug Nuts

After removing the wheel, I saw this: Three Broken Wheel Studs

I was able to tap out the broken studs and replace them with some generic O'Reilly studs and new lug nuts.

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Question What, other than over-torquing the lug nuts as tire shops are known to do, would cause this? These overly-blingy 22" aftermarket wheels also may be thicker than the stock wheels where they mate with the hub. I'm wondering if these require longer wheel studs.

Another disturbing phenomenon: one of the missing lug nuts fell out when I removed the center cap. The other two missing ones were nowhere to be found. This, to me, implies that the last person to put the wheel on didn't bother installing them. Thanks a lot, Tire Shop Dude. It's not like I use this thing to cart my kids around or anything.

3Dave
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3 Answers3

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Fatigue failures of UNTIGHTENED studs ; been there ,done that. When loose , apparently the wheel moves enough to cause fatigue. Fatigue ( axial) fractures are flat as shown in photo. Replace all the studs , it is cheaper than trying to check them for fatigue cracks. I did it on a Nissan Titan , left one front wheel finger tight and drove 900 miles and did not die. I stopped several times to check tire pressure because I could feel "something" in the steering ( smooth interstate), increased pressure. When I got to destination I was sure I had a bad wheel bearing. When I looked at the wheel - NO nuts. Three studs ( of six) were broken -fatigued flat like yours. I pushed out the stud remains and replaced ; otherwise no problem . A week later my son found half a broken stud with nut in the gutter, it had broken off as I made the turn onto his driveway. PS ; I did metallurgical failure analysis for a living.

blacksmith37
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It may be that the rims you have are the incorrect size for your hubs. The hub center in your photos show light rusting where id expect to see some wear or rubbing from contact.

Wheel studs are not intended to hold the weight of the vehicle vertically. They are designed to hold the rim sideways against the hub center. The rim should press firmly onto the hub center which bears the load.

StayOnTarget
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Sir Swears-a-lot
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8

Overtorque is the most common reason in my experience. The next most common issue is corrosion/seizing which then breaks the stud when you try to apply enough torque to remove the nut.

Always use a torque wrench and apply anti-seize to prevent future problems.

If those are pressed in studs you may be able to press them out and replace them. Otherwise you'll likely need to replace the hub.

jwh20
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