Wheel came off at 70mph on freeway....

[Nixid]

What shop in Mesa?

 

[Its-a-4Runner]

This is so crazy! Glad everyone is good. When people talk about "over tightening" what are we talking about? Like 90? 120? 150 ft lbs? Over tightening causes the material to weaken and the thread pitch to change, resulting in nuts that are more likely to back themselves off, start wobbling and sheer.

Did Toyota use a torque wrench to back off the remaining lugs on the other wheels and see what they were torqued to?

 

[wcjeep]

Low torque shear doesn't surprise me. I did something similar on my Offroad Jeep. It's a mistake you make one time.

 

[clo_iam]

Glad you're ok. This is the second time this has happened within a 6 month period. I'm from the area as well, I'm curious, what shop did you go to so I can steer away from them...

I drive often from AZ to LA and after reading about another member's experience I would retorque my wheels before every trip.

 

[cbielat]

Correct me if I'm wrong here but you're saying that you are running spacers and the studs had sheared clean off. Through discussions with multiple Toyota dealers, the verdict was that the torque on the studs was incorrect.

Now with a spacer, the spacer is secured onto the hub using the factory hub studs and tightened down and you mount the wheel to the aftermarket spacer studs. You said the spacers stayed on.

So this is telling me that the spacer failed and nothing with any of the factory Toyota parts.

This is why I have a hard time installing spacers on my truck. From what I've seen and read, it always steers me away from ever installing them. I've been in the industry fro quite a while and yes I agree, although it may not be the right or best way, techs will always use a gun to throw on the lugs. You hardly hear about(not that it can't or doesn't happen) wheels coming off of factory hubs that have been tightened down this way.. You hear far too often of this happening with aftermarket spacers. They must've used an impact for a semi on yours.

 

[Engineer]

Correct me if I'm wrong here but you're saying that you are running spacers and the studs had sheared clean off. Through discussions with multiple Toyota dealers, the verdict was that the torque on the studs was incorrect.

Now with a spacer, the spacer is secured onto the hub using the factory hub studs and tightened down and you mount the wheel to the aftermarket spacer studs. You said the spacers stayed on.

So this is telling me that the spacer failed and nothing with any of the factory Toyota parts.

This is why I have a hard time installing spacers on my truck. From what I've seen and read, it always steers me away from ever installing them. I've been in the industry fro quite a while and yes I agree, although it may not be the right or best way, techs will always use a gun to throw on the lugs. You hardly hear about(not that it can't or doesn't happen) wheels coming off of factory hubs that have been tightened down this way.. You hear far too often of this happening with aftermarket spacers. They must've used an impact for a semi on yours.

I don't see a spacer on the hub in the 1st post photo, my assumption (have not read the thread entirely) is that the factory lugs sheared holding the spacer/wheel combo on.

 

[tb-av]

(multiple engineers from Toyota and insurance companies confirmed that while the spacers place added leverage force on the factory lug nuts, the factory lug nuts would have failed either way due to improper torque applied, the factory lugnuts were seriously under-torqued).

Just a couple of days before the accident I had a local offroad shop in Mesa, AZ, put on new wheels and tire, work on clearance issues, firewall tubing, welding sliders, bodylift, etc. The night I picked up my car they were bolting the wheels on in the parking lot with a hand drill and rushing to finish up.

read the bold... "factory" lugs. Not simply incorrectly installed but seriously under torqued.

Then you have guys in a rush with a hand drill? That was truly the definition of an accident waiting to happen. But I'm sure it still counts towards Internet statistics.

I don't see a spacer on the hub in the 1st post photo,

Lots of bolt holes but it doesn't look like it's sticking out very far.

 

[<<<<]

This may or may not be related to your case but recently there been police reports of idiots untightening some one else's lug nuts as a prank. Mostly school kids crap but potentially deadly.

 

[jasxn]

Hey that's me!

Toyota dealer didn't do shit. The wheel had been on the tire for around 1k miles, so they said it was too long for them to have any responsibility. No one touches my truck, so thankfully insurance did it's job. Unfortunately the shop in the small town it happened in was a piece of shit.

Wasn't worth trying to small claims, as that level of milage was a coin flip on if the judge would care.

Needless to say I check the lugs frequently. Still a bit nervous getting behind the wheel, and I feel phantoms in the wheel all the time (like a wheel is getting loose, but it never is).

Really glad OP is okay!

glad your insurance worked it all out. hopefully you get over the phantom feeling. i got tboned coming out of work and although i can see traffic a lot better now i still feel wary coming out of the parking garage

 

[amalik]

holy shit. title is scary, results -- not so much. thankfully!!!!!!!!

 

[amalik]

This may or may not be related to your case but recently there been police reports of idiots untightening some one else's lug nuts as a prank. Mostly school kids crap but potentially deadly.

if ever caught, they should be hung in public.

 

[gundrted+t4r]

I skimmed the pages and noticed people kind of glossed over the tighten/torque issue.

The biggest concern here is the difference in the lug nuts them selves. In the first post there is a pic of after market nuts that have a chamfer, or angle, on them. Take a note of the OEM lug nuts. They are flat.

The after market nuts have a chamfer that matches a chamfer on the rims. This means the nut contact point in the rim's chamfer. The nut chamfer presses on the rim chamfer and the rim is pressed onto the hub.

The OEM nuts have a shoulder and pass completely through the rim. The nuts shoulder presses on the rim and the rim is pressed onto the hub.

While this may all seem trivial it is actually very very important.

When torquing a bolt the contact between the nut and surface are taking into account by the engineer designing the system. For the OEM system you have a shouldered nut contacting a shouldered surface. This produces 'x' torque and the stud is rated as such to ensure it doesn't fail. The flat contact surfaces transfer the pressure to the stud without increasing the pressure.

The aftermarket system pictured doesn't match the OEM system. While the overall system is the same the contact surfaces are chamfered. A chamfered system increases the effective torque on the stud. This means that a 90ft-lbs torque on the nut is not a 90ft-lbs torque on the stud. Due to the chamfer the pressure on the stud is increased. I don't know the math to figure out how much its increased, but some things I've read (in a different industry) the increase my be up to 30% depending on the angles. Worst case the 90ft-lbs could turn into 117ft-lbs or more. Since the stud was not changed the OEM stud is now in danger of failing.

In a different thread it was mentioned that the aftermarket rims stated hand tightening to 80ft-lbs and NOT using power tools. The lower torque is to compensate for the difference if mounting surfaces.

Over tightening a system with all shouldered contact points will only produce a result of over tightening by x number of foot-pounds. 90+5=95 .... and not a big deal.

Over tightening a system with chamfered contact points will produce a result of over tightening + the increased pressure of the chamfer. (90+5)x[percent increase from chamfer]=trouble