Replacing My BRZ’s Wheel Studs

Broken wheel stud

Last year, when swapping from summer to winter wheels, I found that one of my wheel studs had cross threaded. I discovered this when the stud snapped rather than releasing the lug nut. So it needed to be replaced. I picked one up at the dealer in town and replaced it. This past spring, after putting the summer wheels back on, I wanted to remove one of my back wheels to check something, only to encounter the same problem on a different wheel stud. Rather than snapping it, I gave up and torqued the nut back down on the wheel, intending to resolve the problem later.

A little bit of internet research taught me that this is a very common issue with the BRZ/FR-S/86. The OEM wheel studs, to put it plainly, suck for people who remove their wheels regularly, like autocrossers or track day enthusiasts. They hold the stock wheels on just fine, but the threads wear out quite quickly once you start removing and installing the lug nuts regularly. The best solution is to replace all of your wheel studs with better quality parts.

I learned the hard way, soon after I got my BRZ, that some aftermarket wheels are too thick to fit on the OEM wheel studs. I had planned to share my car with a friend, using his wheels with grippy tires, at a Cumberland Motor Club autocross. I was still rocking my original Michelin Primacy HP Prius tires with no grip. But they didn’t fit on my car because my OEM studs weren’t long enough, so we ran on my Prius tires – slow and sideways. Longer, as well as stronger, wheel studs are a common upgrade. One of the fastest drivers in the club already had them on his FR-S for that very reason. However, I already have two sets of wheels that will fit the stock length studs – the original wheels, and my OZ Ultraleggeras.

Subaru BRZ wheel stud
Photo credit: RockAuto

So I stuck with the stock size, and ordered a full set of 20 from RockAuto. There’s a bulk discount if you buy more than 10, so at $1.46 a piece I paid $29.20 plus shipping. Note the gold color of this stud. The stock ones are silver, while the replacements (made by Dorman) are hardened. That means they’ll be more durable than stock, which is perfect for someone like me who pops the wheels off regularly. As a bonus, it’s a little bit more gold on my World Rally Blue Subaru, which is an excellent color combination and matches my wheels. Not that you’ll be able to see them through the lug nuts, but they say it’s what’s on the inside that counts.

I started on the front, since I already replaced one last year and knew the routine. Jack and support the car, remove the wheel, remove the brake caliper, remove the brake pads, remove the bracket that holds the caliper on, and remove the rotor. This leaves the hub exposed, and it’s easy to work around the brake dust shield to hammer each stud out.

Installation is not the opposite of removal, because you can’t get a good swing with the hammer to tap it in. After trying a few different methods, I found that the best way is to insert the new wheel stud through the hole, put on a couple of washers, and then put on a spare open ended lug nut. The stock ones are closed end, so you’ll need to buy a spare. It doesn’t matter if it’s a perfect match as long as the threads match. I needed a 21mm socket for this nut rather than the stock 19mm, but that’s OK. Anyway, tighten this extra nut down on the washers, and keep tightening it to pull the wheel stud the rest of the way into place. An impact wrench is great for this, but because my batteries died I just kept turning the breaker bar until I couldn’t turn it anymore. Do this ten times, five for each side. The washers and inner surface of the lug nut will get worn and beaten up a bit, but that’s OK. That’s what they’re for, and why we’re not using the same lug nuts that hold the wheels on. Installation of the brakes and wheels you took off really is the opposite of removal. (Well, except for me. Since I was preparing for a track day, I took the opportunity to swap my track brake pads on instead of the stock ones.)

Subaru disk/drum brake

Moving on to the rear, the process was similar, but involved a few more steps because of the parking brake. The BRZ uses an entirely separate parking brake that uses the rotor’s inner surface as a drum. This makes it super easy to swap brake pads – I can just push the caliper piston straight in rather than use some funky twisting motion like my Miatas and Saturns – but removing the rotor is more tricky. I finally figured out that there are two threaded holes on the face of the rotor that you can tighten bolts into that push the rotor off the drum. I was lucky to have some spare bolts around that happened to be the perfect size to pop the rotors off.

Once inside I had to work around the drum brake mechanism, but there was enough room on the side nearest the back of the car to hammer the old studs out and work the new studs in. I’m not sure how well longer studs would’ve worked, but that wasn’t my problem. There was no way I could possibly tap the studs in from the rear to get them started, so I relied exclusively on my lug nut and washers technique to pull them into place. It worked perfectly, and also pulled the rotors back over the drum parking brake.

Reinstall brakes, install wheels, torque everything down, and I was done. I only needed to replace the one wheel stud, but I feel much better having replaced all of them with stronger hardened steel. Now I won’t have to worry about breaking studs every time I pull a wheel off the car. With that, and the usual car preparation for the track, I’m ready for the MassTuning event at the new track in Canaan, NH this weekend.


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