17. We splurged on some new rotors from our local parts store but we did need to make one modification: Explorers use a 5-on-4 1⁄2 bolt pattern, so we had to drill them to 5-on-5 1⁄2. Luckily, our dual bolt-pattern axleshafts served as a handy template for drilling the rotors. We simply bolted them to the axleshafts backwards as shown and used a center punch to mark the location of the new holes, then removed the shafts and drilled them. Crude, but effective. Most machine shops can drill rotors for a small fee.