GMW16755

Description / Abstract: Purpose.

This document describes welding procedures, process details, and acceptance criteria for cosmetic repair of sand cast aluminum engine block castings and low pressure die cast or squeeze cast aluminum bedplates.

Procedure shall be used to weld repair only un-machined and un-heat treated castings.

This procedure is not intended for repair of large casting defects

Repair of oxide films, misruns, and cracks are not permitted.

Cylinder block regions that may be considered for weld repair include block front and rear faces, crankcase (skirt) walls, bosses (excluding head, bearing cap/bedplate, and engine mounting), and starter flange. Defects eligible for weld repair shall be agreed to between the responsible GM Design Responsible Engineer (DRE) and the supplier and shall be included in the process control plan and/or quality document. Any deviations from this specification must be approved by the responsible GM Product Engineering Department.

Repair of high pressure die castings (HPDC) is not permitted due to the susceptibility of blistering.