Wheel Studs

Last weekend brought the final track event for NCC BMW CCA this  year at Summit Point.  Although I had a great time as usual, the weekend wasn’t completely worry free.  If  you run wheel studs instead of bolts, you may not be aware that you need to replace them every couple of years.  I know this, but I tried to delay for the winter, but the gods of oxidation thought otherwise, teaching me a few important lessons.

Lesson 1: Don’t cheat time. If you know a part should be replaced based on time and not wear, don’t push your luck.

Lesson 2: Just because something tightens to torque, doesn’t mean it isn’t about to snap.  I broke two bolts.  Both tightened to torque when cold, even though both had already rotted half-way through.

Lesson 3: Buy a bolt extractor before you need one.

Lesson 4: Assenmacher makes a really cool stud removal tool which will make your life so much easier.  (Assenmacher, that’s funny…)

Here’s a lap when everything went right.

New Wheel Studs

I finally got a couple of days this past week where the temperature in the garage was above 45 degrees so I started to prep the MINI for the upcoming track season. No major changes are planned this year, just routine maintenance items. First up is to inspect the brake calipers and change the wheel studs. For the brakes, I’m checking the condition of the brake lines, cleaning the calipers and carriers, inspecting the piston dust boots, and torquing all of the bolts to spec. Track pads will come later. [And since someone will ask, the rotors at the top of the post are not cracked. That’s just discoloration from the brake pads contacting the rotor when the parking brake is engaged.]

Because my car is outside most of the time, I like to replace the wheel studs every other year. This has been an especially harsh winter so they are really very corroded. The process is not difficult, but getting good leverage in a tiny garage without a lift can be a challenge. Here’s the method that works for me.

Nut to nut

Remove the caliper, carrier, and rotor. Remember support the caliper by something other than just the brake-line (like a hanger or box.) If you’re removing old wheel studs, you’re going to need some leverage to overcome the sheer force needed to get them moving. Wheel studs don’t need to be tightened to high torque levels, but by using Loctite, they can be a pain to remove. I find that I can usually remove them using the double-nut method if I heat the hub first with a torch. You don’t need to get it red hot, but if you heat the area around the stud first, then block the hub from spinning, you can usually get the stud to start moving with a quick hammer blow on the wrench against the top nut. (If I had a lift and was working at shoulder height I might even get it to move just by pulling on it, but I’m working on jack-stands and sitting on the floor.) There are a couple of ways to approach the double-nut job. The right way is to thread the first nut upside down, then put a spacer washer on the stud, and thread the top nut the right way. If you plan to use these nuts on your wheels, this method will protect the cones. If you’re using nuts you plan to get rid of (like me), just thread them together. Put a little red Loctite on each stud and torque 16-20 ft lbs (using double nut method again.)

I’m using Apex Studs and they put together a little video explaining the process.