Xcalliber has specialized in repairing, replacing, and upgrading Allison transmissions since 1984 and offers a full line of stock and performance parts. Whether you have a GM Duramax truck or a fleet of commercial vehicles, Xcalliber has you covered. Want to save money on parts for Allison transmissions? Xcalliber offers cost-effective options, including new parts, rebuilt Allison parts, good used Allison parts, and surplus Allison parts. Looking for a rebuilt Allison transmission? Xcalliber builds dyno-tested renewed Allison transmissions. Need high performance for your Allison transmission? For increased HP and torque, Xcalliber has performance parts and upgraded Allison transmissions for LB7, LLY, LBZ, LMM, LML, and L5P trucks.
Expert technical support and Parts availability. They always go above and beyond.
March 2026
Anything and everything Allison. Excallibur is the spot. They have an amazing shop. It's literally spotless and all they do is Allison Transmission work.
July 2025
Pleasure to deal with start to finish. Excellent quality workmanship & parts. The best in the business.
