Tractech 225M-58 Differential Spider Assembly

The Tractech 225M-58 Differential Spider Assembly (GM 15637904) is a locking differential spider assembly designed for M1028A2 and M1028A3 CUCV military trucks, delivering reliable torque distribution between axle shafts. This OEM replacement from Tractech Inc. carries the manufacturer part number 225M-58 and the OEM part number 15637904, with NSN 2520-01-330-3703, and is engineered for heavy-duty GM axle assemblies and military drivetrain systems. It is commonly used for differential overhaul projects, axle rebuilds, and drivetrain restorations in military and heavy-duty off-road applications where locking differential performance is essential.