Our Peterbilt 330/335/337 Transmission Coolers are here to ensure your truck's transmission performance stays in top-quality shape. Aftermarket Oil coolers and oil cooler mounts help your Peterbilt truck's transmission shift with greater ease and avoid overheating on the road. Investing in a quality transmission cooler for your Peterbilt 330, 335, or 337 is an excellent way to protect your investment and maintain peak efficiency on long hauls.