Basics of Manufacturing

The new Banks Ram-Air Transmission Pans for the Allison 1000, Allison 10L1000 and Chrysler 68RFE are die cast, not sand cast. In his latest video, Gale Banks explains the basics of aluminum casting and why sand casting is a bad idea. 

There are two popular methods of casting aluminum; sand casting and die casting. Sand casting is one of the earliest forms of metal casting. This primitive method involves molten metal being poured into a sand mold. The only thing helping the aluminum to flow into the mold is gravity. The sand mold is rough and typically leaves a rough finish. Another problem is “porosity.” That’s where voids or holes in the casting are caused by hydrogen gas entrapment.  And, when you sand cast, thicker walls are required to avoid “cold shuts.” Cold shuts are where streams of metal entering the mold through various “gates” don’t completely fuse together due to premature cooling. That’s why some of these aftermarket pans are so thick. Often, if you look closely, you can find welds in the casting where a cold shut has been repaired (see video). We never sand cast our lubrication products. This eliminates any risk of sand contamination of the fluid. 

With sand casting, aluminum is poured into the mold. With die casting, aluminum is rammed into the mold. Aluminum is heated to 1,300° and injected into a preheated H13 tool steel mold at 5,500 PSI. The result is a precision casting with no porosity, no cold shuts, and no welds. The surface finish is as smooth as a baby’s butt, which is good for fluid flow. And, the walls will be thinner and dense, which is great for heat transfer and thermal recovery. In other words, thinner, denser walls allow heat to exit more quickly. The only downside to die casting is that the molds cost a fortune, but the result is worth the effort.