2005 Pontiac GTO Brake Upgrade - Speed Slayer

Let the stuff penetrate a while then use a few light mallet taps around the perimeter of the rotor from the back. Eventually, it will come off the hub.

We then installed the Wilwood caliper mounting bracket temporarily using the stock bolts (and washers; unlike the rear, ours had two on each bolt) along with one 1/32-inch shim beneath the caliper mounting bracket apiece. As with the rear, the flat side of the mounting bracket should face away from where the rotor will be.

Unlike the rear brakes, the Wilwood front brakes use rotors that are separate from the black-anodized hats. This necessitates assembling the two using the provided 12-point, 5/16-inch bolts and washers. Use red threadlocker on these suckers and torque to 85 in-lb. Wilwood's GT rotors are the company's top-notch competition rotor, with asymmetrical face slotting and individual dynamic balancing. All this translates to improved performance and rotor/pad life, particularly under sustained high-heat conditions.

As an additional precaution, the rotor-to-hat bolts should be safety-wired to prevent any possibility of them turning their way out. Safety wire is not provided by Wilwood in this kit, so we grabbed some 0.032-inch stainless wire made by Moroso as well as a special safety wire tool (essentially a pair of needle-nose pliers that spins) that makes the process much easier.

Next, we popped the rotor/hat assembly onto the hub. Note that the rotors are directional and unique side-to-side; you should be able to see the internal vanes in the rotor that act to pull air through them as the wheel spins. Pretty "cool."

We put a couple of nuts on the wheel studs and tightened a bit to ensure the rotor/hat assembly was flat on the hub. We then temporarily installed the six-piston brake caliper. Note that there is a left- and a right-side caliper: when correctly installed, the caliper's largest piston will face forward (so that it is the last one to grab the rotor as it spins; orientation arrows are stamped on the caliper as well). Wilwood says this differential-bore piston configuration provides more even pad pressure, extending pad life and improving stopping performance.

With the caliper bolted on, we found that we were unable to insert the inboard brake pad, indicating the caliper mounting bracket had been insufficiently shimmed. Also, since our outboard brake pad sat a touch below the outer edge of the rotor (and also because the rotor hat physically contacted the caliper upon being spun), we decided that the caliper had to be shimmed radially off of its mounting bracket a bit more.

With a bit of shimming, we got everything to line up just perfect, and it was then time for final assembly. All components were stripped off (again, shim locations noted) and the installation began with the caliper mounting bracket. The stock bolts were used and torqued to factory spec (threadlocker used here), and once the rotor/hat assembly was in place, the caliper was installed and its bolts torqued to Wilwood specifications (shown).