GM Service Manual Online
For 1990-2009 cars only

Object Number: 640630  Size: SH

Front axle identification information is stamped on the top of the differential carrier assembly. The information includes the following:

    â€¢ Broadcast code (1)
    â€¢ Supplier code (2)
    â€¢ Date built (3)
    â€¢ Shift built (4) (Optional for 8.25 inch and 9.25 inch axles)
    â€¢ Hour built (5)

In order to verify reports made on the differential case assembly, include full code letters and build date numbers.