For over 38 years now, Used Mack Diesel Engines .com is one of the largest international wholesale buyers and suppliers of used heavy duty truck parts. We stock a complete line of used truck parts including used mack diesel engines, generator sets, heavy duty truck transmissions, rear ends, and all related small parts (such as starters, alternators, compressors, etc.). We have a large inventory on hand at all times, capable of supplying you with what you need, when you need it, and at a reasonable price. No order too large or too small; order one piece or a trailer load.