A604 4-Speed Automatic Transmission

The Spartan 11155T is a fully remanufactured 4-speed automatic transmission from the A604 transmission family, designed to meet or exceed Original Equipment (OE) specifications. This transmission has undergone a comprehensive remanufacturing process that includes a thorough teardown, triple cleaning, chasing of all threads, and installation of new bushings. The valve body is rebuilt and tested using a C.A.R.S. testing system, and all new O-rings, gaskets, and seals are installed during reassembly. This transmission features specific upgrades to address common A604 flaws. It includes clutch corrections to prevent harsh 2-4 clutch engagement by drilling an exhaust hole in the 2-4 pistons, and upgrades to heavy-duty planets and transfer shafts for increased torque capacity. A complete bushing replacement with custom-spec bushings is performed to improve internal fluid flow and stabilize pressures. The valve body and torque converter are also upgraded to fix factory hydraulic flaws, with updated servos, solenoid blocks, switch valves, valve body accumulators, and an anodized PR sleeve for responsive shifting and increased torque capacity. The transmission pump is fully remanufactured with new line bore bushings and precisely torqued pump bolts to eliminate front seal leaks, and includes an under-pump cooler bypass valve replacement and a 4-ring stator with Teflon rings. Each remanufactured transmission is performance-tested on custom dyno testing machines that spin and load test the entire system, simulating real-world use with fully synthetic automatic transmission fluid and a filtration system. Powertrain Products offers an available 7-year, 1 million mile warranty and free core return shipping. The transmission's OEM assembly numbers are 48005400AA and 4800546AA. It is important to note that this product may not fit your vehicle. Please verify fitment using the provided tools before ordering.