Loose lug nuts and broken studs

[Robyn]

The other day I replaced the tires and wheels on my 91 Burb 4X4 with a different set.
The ones coming off were trash and the new set was 90%
I found the left front wheel to have 3 of the 6 lugs loose ( very very loose)
I chalked it up to a flake at the tire shop before I got the rig.
THE PLOT THICKENS
yesterday I went into town to the store and noticed a thumping sound the closer I got to town.
On the way home the thumping got bad so I pulled over and the left front wheel Had one broke stud and all the nuts were loose again.
I tightened them good the first time so they should not have been lose is less than a week.
I stopped at the parts house and got 6 new studs and nuts.
I removed the wheel and the brake caliper to gain access to the back, nope rotor has to come off.
Its at this point that I find the hub has a ton of slop on the bearings.
tearing it down revealed nothing unusual other than the wheel bearing nut lock washer and lock nut were not tightened down properly.
I checked the bearings and replaced the studs. The things runs smooth and all seems well now.
The truck recently had the bearings repacked at a GM dealer according to the service records.
This little issue very well could has resulted in a traffic mishap that could have been serious.
I wonder why this happened, the parts were all installed in the correct order but the torque on the bearings was incorrect, it makes no sense????????????/
I tore intom the the other side today and found all to be fine.
Well it gave me a chance to replace the automatic hubs with a nice set of U twistems from Old MA WARN.
Feel much better now that I have had my hands in there. Really spooky when wheels come loose.
I often wonder how many traffic crashes are the result of poor quality mechanic work getting out the door????
Best to ya and be safe. OH Check them wheel nuts will ya. ;0)

Robyn

[big61fourby]

Really spooky when wheels come loose.
Robyn

Ya, no kidding. Happened to me once, and needless to say, I'm much more aware of strange vibes after rotating the tires.

All this talk makes me miss driving a good 'ol solid axle truck. My left leg also really misses having it's own pedal Maybe someday...

Glad you caught it in time!

[rustyk]

I think this is the Clue: "The truck recently had the bearings repacked at a GM dealer according to the service records."

Ever seen a GM tech with a torque wrench in his hands? I don't even know if any of 'em has one in his toolbox.

This is one of the reasons I do most of my work myself (and probably why you do, too.) And I have three torque wrenches...

[Robyn]

The tech does not need a torque wrench to do the wheel bearings, most would not know an inch pound from a marshmallow.
I just snug the inner bearing nuts down with a short 3/8 ratchet and intall the locknut, if it needs a little to make the hole lign up I will usually go slightly tighter rather than looser. I install the lock nut with a standard breaker bar on the nut socket and reef on it realy good. I have NEVER had a set of bearings come loose or fail because of installation practices.
The lug nuts were put on by me with an impact wrench and they were tight.
Again I have never had a set come loose.
Having the wheel bearings wobbling around especially with the heavy offset wheels must be the key as to the reason the nuts came off, especially when they were loose when I got the truck.
The other side (RH) was fine and I did check them as well as tear into the bearings too for a look see.
Could be a shift change and things got forgotten or just???????????
Robyn sits warrily in the drivers seat with a lug wrench within easy reach! ! ! ! :0)

[HammerWerf]

Robyn,

The last time I had the tires rotated on the 99 Suburban at the tire dealer I bought them from, I asked if they were going to torque the lugs to the required torque (140 lb-ft for this one). I was told that they only torqued the lugs on the small cars, on your big suburban, we just run them tight with the air wrenches. When I got the truck home, I went about setting the torque myself. I set my torque wrench at the 200 setting to bust the nuts loose. Here is what I found. 2 lugs on one side, and 3 lugs on the other were greater than 200 lb-ft of torque. the rest were just barely snuged up. Reset all lugs to 140 as per the requirement for my model year. Great way to screw up the front rotors (as if there aren't enought ways to do it already). I've gotten better results at Sears.

HammerWerf

[Subzilla]

Happened to me last April and sceerred me and the wife to death. Traveling to the coast with loaded down Suburban, kids in back seat, pulling pop-up camper doing about 70 mph, I get the vibes and thought "flat tire". I proceed to safely but quickly slow down and look in the driver's side mirror to see my left rear tire wobbling. I thought "what the heck???". After stopping on the shoulder, I inspect the tire and much to my shock find that out of the 8 lugnuts and studs, ONLY 2 are left holding the tire on and those are half loose! The other 6 were totally gone. We had just stopped for lunch and I wonder if someone tinkered with them. I had rotated the tires some 3 months/3000 miles earlier and I can't imagine them coming loose but what do I know. Anyway, 3 hours later and a AAA tow to local shop that dropped what they were doing to fix me up, I'm heading down the road again. They had to get parts from 3 different places as my 3/4 ton has a heavy duty setup and the listed parts never match the actual stuff. The other 3 wheels were tight as a drum. Never had that happened in the 12 years I've owned the thing and I've had the wheels off a hundered times. I still shudder at the thought of driving another 100 feet or less on just 2 lugnuts and what could have happened at that speed pulling a camper.

[DmaxMaverick]

Could these studs have been replaced, and not fully seated? The best method for seating the studs is off the truck in a press, or with a hydraulic puller type. Seating them with the nut/washers/grease method may not fully seat them. It can take over 300 lb/ft to get them pulled all the way in.

BTW (in case you didn't know), never use the nut(s) used for seating studs to mount the wheels. They will be fatigued beyond usefulness.

[Robyn]

Maverick
The studs were I believe the originals and were tight.
The issue was the loose wheel bearings allowing the hub to wobble and along with the heavy offset wheel caused the things to come loose.
I checked the torque this morning after I had replaced the studs and stuff and it was within spec.
I install the studs with a 5 pound club and a big 1 inch drift and then push them in the 20 ton press to do the final seating. After they are bolted on and run a few miles I check them again.
This was just a screw upon the mechanics part.
But it was a handy time to install a nice set of Warn hubs and park the auto's on the shelf.
Looking more like as real 4X4 all the time.

[rustyk]

The tech does not need a torque wrench to do the wheel bearings, most would not know an inch pound from a marshmallow.

Well, you have a point, there...on my Fords and older gaso G30, the spec is to torque it to xx lb.-ft., then back it off, which is what I do.

[SoTxPollock]

The very few times I've let a dealer remove my wheels and put them back on the bill always had a note on it to recheck torque after driving the vehicle. You should always recheck the torque. I've seen one or two lugs loosen for up to three times before they finally take a set and don't move the next time I check them and yes, uneven torque will help warp the rotors.

[Robyn]

Its been a month now and all is well.
The loose wheel bearings were the issue that caused the nuts to come loose.

[DA BIG ONE]

No matter how many times or how big a tip I give it's always stripped lugnuts and studs when going to any shop. They always put lugs in the gun socket to thread it on, run it down w/o any concern whatsoever, I try to check em right away now to make the shop pay for em when they get damaged from a lazy a___le......

Nothing, like being stranded w/flat tire because some AH over torqed the lugs.

[CapnAmerica]

FWIW, my local Sam's Club(!), which generally has the best tire deals around here, also has a procedure whereby one mechanic does the tire installation and a second one verifies the torque setting after installation...using a torque wrench! It's a clicker kind, set at 140 lb-ft in the case of my subs. I always watch through the garage window to be sure they perform this check. What I can't tell is exactly what the setting is on the wrench, but I DO watch the amount of effort the mechanic puts into pushing the wrench, which is sort of an indicator of torque. So I haven't had the loose nuts problem lately (though years ago Sears left my lugs loose on my '66 Mustang 2+2 the same day Allstate canceled my auto insurance due to a clerical error ).

NOW...if I can just get them to tighten the stupid GM plastic nuts on the center covers without leaving THEM loose or stripping them!

One other part of their procedure (Thank you, lawyer corps!) is, if the customer has aluminum wheels, the nuts will be retorqued later.