broken stock lug bolt- best method to proceed? driveable on 3?

[clydesdale]

I snapped a lug bolt. I also can't get the damn allen screw out for the front rotor. Any suggestions on how to get the remaining bolt out of the rotor? Was is the best method and can I drive like this for a little while? Thanks.

[Sagaris]

If you visit the ghetto you will be amazed at the ability for a car to be driven with a minimal number of lug nuts. I am not a huge fan of the idea mostly because you could get lazy and just never fix it and let it put additional stress on the remaining 3 bolts which I am assuming have 20+ years of use on them.

I hate dealing with broken fasteners and am not good at it and the only advice I can give is to start is with a center-punch. Don't try to drill anything without making a good mark with a punch. My method of avoiding having to drill things out is to buy a rust free car from the southwest, and not drive it in the winter :D

[jlevie]

You will probably have to drill out the rotor retaining screw. Pick a drill that the same diameter as the body size of the screw. Drill just deep enough for the head of the screw to come free. That leaves enough of the screw to be grabbed by vice grips. Once the rotor is off you may be able to grab the broken lug with vice grips from the back side and get it out. Worst case, you'll have to drill it and use an easy out.

FYI: when removing a broken fastener it is best to use a left hand twist drill. In a good number of cases the counter clockwise rotation of the drill will back out the fastener.

[nando]

I was forced to drive into town after I broke a stud on the track. I was very fortunate to find some standard bolts at a local auto shop; BMW thread pitch with cone seats are not easy to find in small town canada. Fortunately the 4th shop I went to had 3 which I gladly paid for ($5!), and I was happy I bought all of them because another stud broke during the next session.

Lesson learned: never use an $80 stud kit for anything but grocery-getting. I don't care how your "hard driven" street "dorifto" car has held up fine for 6 months with them.

basically I think you might be OK for short distances and low speeds. I wouldn't get on the freeway like that. keep an eye on the torque of the remaining 3. And of course replace it ASAP.

[clydesdale]

Well, it is not in there loose. It tried double nutting it and I was able to get the second nut on just a little. I applied some torque and the second nut fell off. But, I did put some torque into it, so it is not in there loosely. I guess it is time for plan b.

[learningcurve86]

you could shatter the rotor to get it off if you really wanted to, doesn't take a whole lot to turn one into scrap.

[clydesdale]

I got the rotor off by drilling out the set screw as Jlevie suggested. I have about an inch worth of bolt to hold on to. But, it is in there. I could weld one of the nuts on, but I don't want to over heat the hub. I guess I would use wet rags around it or I could remove the hub and drill from the rear. What do you think?

[Sagaris]

clamp some vise-grips on that sucker as hard as you can and you should be in business

[clydesdale]

Sagaris, any suggestions on stabilizing the hub while I turn? Also, I understand what you are saying, but not sure why it will work. I snapped a bolt head trying to turn it with a socket with the tire on the ground. I had great grip and leverage. Why would vice grips work? Is it really that the bolt head seizes to the wheel? I thought the threads are what is seized. Thanks.

[Sagaris]

Thread two of the lug bolts into the hub and use a bar in between them to hold the hub still. Think of a percent symbol % as the heads of the 2 lug bolts then the bar in between them. The threads seize but when a lug bolt is over-tightened, the yielding occurs at the base of the head just before the threads start. This is also a potential area for stress concentrations to occur. More or less, it is a weak point. Your only struggle should be getting grip on the remains of the bolt in which case I have always had great success with a set of clean vise-grips clamped as tight as possible over the broken bolt. Welding something to it is another option, but not everyone is comfortable with that/has access to a welder.

[jlevie]

I suspect that the problem is that the threads in the hub are damaged, in which case there would be no point in removing the broken bolt as the hub will have to be replaced. But if you want to try, you won't hurt the hub by welding a nut onto the stub of the bolt.

[clydesdale]

sagaris, will the percent symbol idea work? Did you use a thin rod? I just can't invision the rod bending to get inbetween the two bolts and not get in the way of the center of the hub. The car is nowhere near me right now, or else I would just go out and look.

[Sagaris]

There is definitely enough room to stick some sort of bar between the lug bolts and wedge it still. A jack handle may be too large of diameter for it to work but you should be able to find something with a small enough diameter that is stiff + long enough to get some leverage.

[clydesdale]

ok, I saw a video on the net of something similar. I have a much better idea now. Thanks. I will try this and the vice grips and see how I do. If that that doesn't work, what do you think about removing the hub and drilling it from the rear and then twisting with what is left? What are my chances of getting the hub off without breaking the abs sensor or the bearing? One site mentioned that the bearings will like disintegrate as I take them off. Any thoughts on that?

[Sagaris]

The ABS sensor will not really be at risk with what you are doing, if it happens to be in the way then it is easily removed with a 5mm allen wrench.
You should be able to get it handled without resorting to removing the hub. I cannot say for sure whether the bearing will be ruined by removing the hub as I have never re-used a bearing that I have removed. I have just been taught to consider them junk if you remove them.

If things are just unbelievably screwed and you dont mind spending ~$125 then it wouldn't be the end of the world to buy a new hub, bearing, axle nut, and lock ring but hopefully you can get it off with relative ease with some PB blaster/penetrating oil, some clean vice grips and a clean dry bolt.

Here is a visual of how you could hold the hub still. The yellow handle is wedged between the two wheel studs