Today, one of my coworkers heard a "clunk,clunk,clunk" noise while moving our truck out of it's bay. Then came inside and said "we got a problem". So I go out and they removed the wheel cover from our left front tire. I see 3 out of 10 lugs sheared off with one rolling around in the cover.The three lugs were in sequence. Two studs were shiney, one was dirty. So one had been gone for a while. Im not naming names and will just say this. We have the best equipment money can buy and change out tires at 6/32, so maintenance is not a problem. I have never seen three lugs sheared off like this. No prior vibrations in the cab, damage to the wheel and it has not been in an accident.

So I am curious if anyone else has ever seen this type of a problem?
And what could have caused it?

 

Looks like someone loosened your lug nuts.

 

The truck is never left alone long enough and secured in a locked bay at night so it would be almost impossible for someone to loosen them. Anythings possible but Im just having a hard time believing that since It's a fire truck.

 

What it sounds like is maybe a bad atch of STUDS for teh lug nuts. Change ALL of them for the hub since they would be from the same lot and the other side also as a precaution should not take more than around 6 hours 2 new wheel seals and 20 studs and nuts. Tools needed a large press the old ones out and the new ones in also a torque wrench to make sure the new nuts a torqued right seal driver to drive the sealhome punch to remove the old seal and hub nut to remove the hub from the spindle. Have fun.

 

Could be that these lugs were really never tightened correctly? It happens! If the tireman gets in a big hurry, they will misalign the wheel (even slightly will do it) the lugs on one side are tight as a banjo string, the others are loose, a few miles and a few real wonky areas and the stress just causes them to pop.

 

Are they Unimount wheels?

I've seen a couple instances (on dump trucks)where all 10 studs have failed and wheels have come off.

How old is the truck?

Could be metal fatigue from repeated tire changing (some tire guys just love to overtorque the lug nuts).

If they're Unimounts, just hammer out all the studs with a good sized sledge, then put in all new studs and draw them into the hub by putting a nut on each stud and using an air impact wrench to tighten the nuts, which will "press" the studs into the hub holes. Then remove the nuts and install the drum and wheels.

Be sure to properly tighten the lug nuts.

No need to pull the hub to replace Unimount studs.

Be sure to replace all 10 studs. If 3 have failed, the other 7 probably aren't far behind.

 

I'm thinking also that it could be caused by a simple thing like a spacer not seated all the way in. Tightening the lugs should seat it but you never know.

 

Spiltshifter take a word of advice form a former mechanic who pulled wrenches before driving and was also a shop formen. If I EVER CAUGHT any of my mechanics changing a stud the way you just stated he was fired and shown the door with my BOOT IN HIS A$$. You never ever use a sledgehammer and impact guns to change a stud there is to big of a chance of cracking the hub and then you are screwed if that happens. With a unimount hub the factory specified procedure is remove the hub from the vechile then using a press carefully press out the studs then press in the new ones then using a torque wrench to tighten the lug nuts that way you do not damage the studs or hub. This would not have happened in the first place had they used a torque wrench instead of an impact gun. A 8-10 hole unimount wheel only needs 450 ft-lbs of torque to be held securly on the normal 1 1/2 inch tire gun shops use has 1500 ftlbs slightly over torqued you would think.

I never used a gun larger than a Mac 4400 to do anything on a semi produced 600 ftlbs of torque and could handle run the lugs down so I could get the torque wrench out for the tires.

 

Sure glad I never worked for you.

I pull wrenches too ya know.

No sense making a major operation out of a simple job.

 

IN todays SUE happy society failure to do things by the book though would result in YOUR butt being the one being hung not the manufactor of the studs or the hub. If you changed the studs in the manner you stated and the hub broke and the wheel fell off and say someone got killed and then it came out that it was due to your not following proper maintance procedures. You will be the one paying for it with the civil settlement being garnished out of your check and that cloud hanging for the rest of your life. I had a mechanic at PFT roberson changing studs on an Unimount right after I was made shop formen for nights the way youu recommended he was fired and I personally redid the work. The next week the hub he was working on was checked at the factory by Rockwell itself. They found 4 impact cracks and 2 of the NEW studs were cracked also from the way he had installed them. My way may be slower BUT it is safer for all parties involved. And if it is an Alloy hub like alot of them are hitting it with a hammer can bend it and then you are in a WORLD OF HURT.