It is not safe to drive with a broken wheel stud because once a stud breaks, it puts additional pressure on the remaining wheel studs, causing them to eventually break as well. It is dangerous to drive with a broken wheel stud because the wheel will start to wobble and could fall off and possibly cause an accident.
Usually, the wheel studs will only break off while driving if you have a loose wheel on your car. The loose wheel might be due to over-torquing or under-torquing the lug nuts when the tire was installed - either way, the problem probably originated when you last had new tires put on.
The wheel studs that go on your car are made of metal, which means that they should last a lifetime. Due to wear and tear over the years, a wheel stud may have to be changed out. Neglecting to get a wheel stud replaced when it is damaged can lead to a number of unsafe situations.
If you don't wreck the threads getting them out, they should be fine.
Putting oil or any kind of lubricant on the wheel bolts, wheel nuts, or wheel studs is a very bad idea. If the surfaces are encouraged to slip, as oil would do, the wheel can come loose. Rust on these areas is common, and it does not matter as it is only on the surface.
Depends on your wheels offset and how far out you want to go.
You will need to measure the overall length of the stud, the diameter of the threaded shaft and the diameter of the knurl or collar of the bolt directly under the stud head.
It can be measured in either standard (1/2", 9/16", etc.) or metric (M12, M14, etc.). The most common thread sizes are 12mm, 14mm, 7/16", 1/2", 9/16", 5/8".
1/2" spacers are going to leave you without enough stud for the lugs to safely hold the wheel. You would be better off replacing the studs with 1/2" longer ones.
What is a Wheel Stud? The studs on your wheel hubs, along with the lug nuts, keep your wheels firmly attached to the wheel hubs and axles on all four corners of your vehicle. Wheel studs are nothing more than large bolts that are designed to fit securely into your wheel hubs.
While a lug nut screws onto a threaded wheel stud that is attached to the hub, a lug bolt eliminates the need for a wheel stud. Its design allows the wheel and the brake rotor to be directly attached to the hub.
It's much easier to align and install your wheel on studs, rather than fussing around trying to line up the hub, rotor and wheel, all while supporting the wheel with one hand and trying to get the bolt started with the other. Stud and nuts for the win, in my humble opinion.
There are actually a variety of different lug nuts and lug bolts out there. Each of the eight different types have their own distinguishing features. Many of these you'll rarely encounter outside of a busy commercial garage.
As long as your studs stick out beyond the front surface of the wheel by at least the diameter of the stud, you are good to go. Simply put, if your stud diameter is 7/16" or 1/2" and you have 1/2" of stud length protruding beyond the wheel you are in compliance.
1/4" is the razors edge of not needing them. Any thicker and you'll need longer studs.
5mm spacers will not require longer wheel studs.