Overtightened lug nuts

tires
repair
wheels

#1

I took my car to my usual trusty mechinic. Trusty asked where I had had the last rotation done. All the lug nuts were overtightened. The manual says to tighten to 96 pound-feet (that’s a measure of torque).All the nuts were tightened well past this. Many came loose at 200 foot-pounds. More at 300 foot-pounds (that’s as high as they wanted to go with their pneumatic torque wrench). There were still 5 nuts that didn’t budge.
They brought out the manual torque wrench and muscled 4 of those loose. But one on the left rear wheel wouldn’t come loose. So they made it a 3-wheel rotation, and left the left-rear wheel in place.
I had a pucture driving over a piece of road junk last spring out of state and had to buy a new tire. Clearly the people at Roadside Tire had no clue (although why they messed with the other three wheels is a mystery. But although the left rear is the newest tire, i still don’t want to have to trade the car in when the tire is worn! Nor do I want to trash out the rest of the assembly (i have no idea what that would involve or cost).
Any suggestions about what to do? (Clearly finding Roadside Tire back and using their lug wrench on the vilain who did this is not an option.)


#2

You need to have the shop get that last nut off, if you break the stud then the shop can replace it. Otherwise you’ll be stuck if you get a flat.


#3

Hit the lug nut with an impact gun and hope the stud doesn’t snap off.

Tester


#4

They brought out the manual torque wrench and muscled 4 of those loose.

The torque wrench is used to tighten only. Nobody cares about break free torque and the wrench isn’t designed to handle excessive leverage. A length of pipe over a breaker bar and 6 pt socket will remove the nut. Then carefully inspect the threads for damage.

BTW- break torque is not necessarily indicative of initial torque but when you can’t break them free under normal means, they can be assumed to have been over-torqued.

I use a 600ftlb impact gun to remove stubborn lug nuts. What shop is limited to a puny 300lb unit???


#5

You have no choice now but to follow Tester’s advice. Know that replacement of a busted stud is not a mind-bendingly huge task. The hub will need to be removed and the old stud pressed out and new stud pressed in on a hydraulic press. Shops have to do this all the time. I’ve never seen a shop without at least a 30-ton hydraulic press.

I’m actually surprised your guy left the wheel on that way. That’s kind of a half-arsed job IMHO.


#6

Try using an independent tire shop. They deal with this sort of thing all the time.


#7

To replace a stud, I have always done it on the car. I punch out the old stud with a hammer (and a drift if necessary) and pull the new one in with a nut and a stack of washers and oil on the threads.

As far as getting the wheel off, I have never seen a nut or stud that a good breaker bar with a pipe over it couldn’t overcome.


#8

Oldtimer, that’s a common approach too. I find a hydraulic press easier.


#9

Not all studs can be replaced in that manner.

Sometimes there’s not a feature in the hub/knuckle that allows the installation of the new longer stud to be installed. So the hub as to removed.

Tester


#10

And since this might be on a Mercedes (“MB Girl 2005”), I’d rather do it with a press, who knows how sensitive the wheel bearings are, and they’re for sure expensive!


#11

There are some unknown variables here. Whether or not the stud threads were damaged before the prior rotation was done, any corrosion factor, the use of an air wrench to determine torque while being influenced by pressure and CFM, etc; and a torque wrench to break loose lugs?

Sure that wasn’t a larger drive ratchet or breakover?

The shop was in there already and if the stud breaks off then so be it. The repair is not difficult.


#12

If it is evident that the nuts were severly overtightened the studs and nuts should be replaced even if they don’t break when twisted off but it sounds as though they will break when enough torque is used to turn them.


#13

Pulling a hub isn’t always so easy either. On my Saturn, it required removing the steering knuckle and pressing the hub out.


#14

I’ve often done it the way oldtimer 11 does it. I drive the broken stud out with the wheel still on the car with the other 4 nuts still attached. This extra mass helps absorb the shock of the hammer blows. This minimizes any stress to the wheel bearings. They pop out quite easily. Then I remove the wheel and rotor or drum then draw the new stud in using a couple washers and a lug nut screwed on backwards (cone side out).

Of course, as Tester says, sometimes the configuration won’t allow this.


#15

I could only understand the mechanic sending you home that way, if he told you to come back at a later date, and he’d order a few new studs in case he broke any.

If that was not the case and he just told you to keep driving it that way, he’s nuts.

You get a flat tire. Instead of just changing it, you will need it towed to someone to remove the wheel and replace any studs broken in the process. $150 towing bill and the cost of fixing this, VS just fixing it now while it’s in the shop. Not to mention the fact that when you do get that flat…you may be 100 miles from your normal shop…on a Sunday…holiday…at 11pm…in a snow storm.

Get it fixed now before it involves too much more.

Yosemite


#16

@oldtimer is right. The guaranteed easy way to get it off or break it in a pinch is quite simple. Leverage and penetrating oil. Any pipe that fits over the end of the wrench will work; the longer the better. 3 to 5 feet is more then enough. I had one last one to get off that I experimented with to see how little effort it required. I used a half mast from a small sail boat, about ten feet long. I set the wrench on 11 o’clock and the weight of the mast just turned the nut off. Obviously, if it is really stuck, it will snap it off. It has always worked for me without breaking but others say it can snap it off in a heartbeat… But I agree…if it requires this much leverage, take it to a garage. I suggest too, you tighten it “slightly” with less effort…to break the hold. There is less chance of breaking the stud if you do this first.


#17

@texases‌

Mercedes-Benz does’t use lug nuts . . . they use lug bolts

And when one of them won’t come out, and the strongest air impact, and the longest pipe won’t remove them, it gets ugly

I’ve had to drill out a few, and I noticed a pattern . . . the ones that don’t want to come off are usually the ones with aftermarket chrome (Benz never offered factory chrome). I don’t even pretend to understand, but I’m assuming that the difference in metal between the lug bolt and the junky chrome may be the problem

I’ve also seen situations where the stock, unchromed alloy rims had stuck lug bolts, probably due to overtightening. Putting the car on the ground, and using a breaker bar with a pipe usually broke those free. In a few instances, I’ve seen very powerful 1/2" drive air impacts actually sheer off the lug bolt heads. At least the rim cleared the remaining portion, and then it was down to drilling and extracting. But it sucks when you have to drill and extract, and the lug bolt is still there. What’s worse, sometimes the lug bolts are recessed

I’m proud to say, in those situations, I always upsold the heck out of those jobs. It’s not my fault that some guy before me overtightened the lug nuts, or the customer chose to have junky chrome applied, which seems to promote lug bolts seizing. I would make them sign a document which stated that any damage to the rim, due to drilling and extracting, was not going to be held against me. I would not even start the job until it was signed. I would always tape off the rim as best as possible, but I had to cover my butt, in case things got ugly. They never did, by the way

And I would also inform the customer that as long as they used chrome rims, the problem might happen again. I told them their best bet was the stock rims, unchromed, stock lug bolts, unchromed, and always use the torque wrench. Whether that went in one ear and out the other, I don’t know. But I said what I had to say. You can’t force the customer to make the right decision


#18

What a pain. I guess it’s a German thing - I had those kind of lug bolts on my GTI. Never over-tightened them, at least!


#19

@texases‌

It may very well be a German thing . . . considering that the German brands tend to use lug bolts, not lug nuts

Just imagine if somebody buggered up the female threads. Now you’re talking about installing a helicoil in the hub . . .


#20

It’s important to address this with due speed, as you don’t want to deal with this after your tire gets a flat and you are sitting on the side of the freeway. If your car uses traditional lug nuts, as mentioned above it should be possible to remove the tight nut irrespective of how tight it is, using an appropriately sized breaker bar and socket and some add’l leverage. You know what Archimedes said right, with a big enough lever he could move the world. You don’t need to move the world, so your problem is even easier.

Your mechanic may need a 3/4 or 1 inch drive & socket, and some pipe for add’l leverage. If that doesn’t work – and it might not if the nut is damaged or deformed already – there’s always heat and a file. And if that doesn’t work, there’s a gadget called a “nut breaker” where you tighten down a hardened chisel point onto the nut, and will split the nut right in two. I’ve had good luck with this technique on seemingly impossible to remove nuts.

And if all else fails there’s always a cutting torch. And there are even more wily ways to do this I expect. Think about it this way: If bank robbers can open safes that are designed to be un-crackable, it’s got to be possible to remove something as simple as a stuck wheel nut, right?

Once the wheel is off it’s critical to make sure the threads on the studs haven’t been damaged or stretched. Don’t let the mechanic simply torque on some new nuts and call it a day. Besides a visual inspection of each stud with a thread chase device, make sure all the new nuts will thread onto the studs using only hand force right up to the point where they contact the wheel. Insist the mechanic show this to you, so you know that it can be done. Best of luck.