Modern single and double overhead cams can be rebuilt in today's remanufactured engines. Overhead cams can be reground and, in some cases, roller cams ahve lob wear that still falls within factory specifications. The main problem is oil seal groove wear. The need to have no oil leaks in this area is critical because of timing belts and pulleys. Micro Sleeve overhead cam repair sleeves address this problem so expensive overhead cams can be reclaimed with no compromise in quality and wear life.