How do you change a broken or stripped wheel stud bolt? Most of us use a hammer and punch to drive the broken stud from the hub, use the hammer to tap in the new stud, then pull it the rest of the way into place using a lug nut.
I've learned that's technically the wrong way. In a perfect world, the broken stud should be pulled/pressed from the hub, and a new stud should be pressed into place. That requires either using a special puller to remove the old stud and install a new one while the hub is still on the axle, or to remove the hub from the axle so the hub can be put in a hydraulic press for stud removal and installation.
Experts say that--especially on cars, vans and light trucks--driving broken studs from hubs can shock-load and potentially damage the bearings in the hub. They admit that the damage would probably show up only under extreme conditions, which is why NASCAR teams either remove hubs for stud replacement, or use special pullers to remove/install studs on the car during emergency pit stops. The other concern about the traditional way to install new wheel studs is that the beating and pounding often leaves the wheel stud slightly cocked to one side. Most of us just install the wheel and assume that the stud will self-align when we snug-up the lug nut. Yes, it does, but the experts tell me that as the stud re-aligns, it may leave the lug nut slightly loose. If you replace all the studs in a hub, and all of them end up slightly loose as the new studs settle into place, the wheel could end up somewhat loose on the hub, with catastrophic consequences.
So, should farmers and amateur mechanics take the time to remove hubs and use a press to remove studs? Should farmers or amateur mechanics buy special stud removal tools so they can remove studs with the hubs mounted on the axle? Or should we continue to use the tried-and-true "beat and pound" procedure to remove and install wheel stud bolts?
Since most of the studs I have to deal with are on heavy-duty ag equipment, and because I don't live in a perfect world, I'm probably going to continue to beat and pound. But when I work on my wife's SUV, or do work on smaller machines with light-duty hubs (like my boat trailer), I'm probably going to consider a more delicate, refined approach to working with wheel studs.
And--if it matters--another thing the experts told me to be careful of when replacing wheel stud bolts is to try and align the splines on a new wheel stud bolt with the splines already in the hub. They said that "cutting new splines" can theoretically lead to a reduction of the inside diameter of the holes in the hub, which could lead to problems in the future.