Shop for Aftermarket Drivetrain Parts for the Sterlin L-Series. Keep your rig running strong with a full lineup of drivetrain essentials: Our product lineup includes: Pinion nuts, seals, U-joints, lift axles, and electronic sensors. Top Brands: Trusted names like BESTfit, TPHD, and Rockwell. Built Tough: Designed for heavy-duty use and long-lasting performance. Whether you?re replacing worn parts, upgrading your setup, or tackling repairs, this product lineup has everything you need to keep your Sterling L-Series truck powering through the miles.