Lug Stud Swap

Back when I changed my brake pads I found that one of the lug studs on the driver’s side rear tire had stripped threads. Or maybe the process of taking the tire off stripped the threads. I’m not sure. But I would need to change that lug, and that’s what I did this weekend.

After removing the tire, the first step was to get the brake caliper out of the way. It was held on by two rather stubborn bolts. After sliding out the pads, some Kroil and a breaker bar made short work of that. I threaded some twine through the caliper and tied it to the spring to prevent the hard brake line from getting damaged and moved it to the side.

Next I removed the brake rotor. Remember to disengage the parking brake as the rotor won’t budge if the parking brake shoes are engaged. Then I put a sacrificial lug nut on the stripped stud and hit it with a hammer until it popped out.

Old (right) vs New (left)

The stud is kept in place in the wheel hub by the splined base section which is slightly oversize. This means that it needs to be pressed in, a task that is likely much easier to do at the factor before the dust guard and parking brake mechanism is installed. Since those two bits were already there pressing the stud in proved to be more difficult. I eventually did it in two steps. First I clamped the flared base of the stud with locking pliers to help keep it from spinning. Then I used a stack of washers as spacers and started tightening down a lug nut. The idea was that each turn would pull the stud in a little more. Eventually it was in far enough that it wouldn’t spin on its own. At this point I put the brake rotor back on and used the same lug nut and washer technique to snug it in the rest of the way.

I marked the end of the stud with a Sharpie to make sure it was not turning as I tightened it down, and I had to remove the rotor a couple of times so I could see if the stud was all the way in. Eventually it got there, so on back went the caliper, in went the pads, and on went the tire. I know there are torque specs for the bolts that keep the caliper on, but there was no way to get my torque wrench in the wheel well, so I’m going with the good old “not gonna fall off” feeling.

And there you are. The replaced lug stud gleams shiny and chrome, and the tire is back on.