Ford 9 Inch Nodular Iron Cases
FACTORY CAST IRON VS NODULAR IRON
OEM Ford 9 inch cases were first made from cast iron only. This material was inexpensive, easy to pour, and offered acceptable strength for the time. Later, certain applications became more demanding and required a stronger case. More material was added in critical areas including additional webbing. Since cast iron tends to be brittle, a new material was also required. An agent was added to cast iron to create a stronger molecular bond. It made the case more ductile and less prone to breakage. The result was named “Nodular iron” and thus the nodular 9 inch case became the sought after case for heavy duty applications. During WW II, high strength materials were being diverted to military applications. While the casting design remained the same, the material reverted back to regular cast iron. These are often referred to as “WAR” cases. The factory main cap bore sizes are 2.891” and 3.062”. The same casting was used for both cases, but some uses required bearings with a higher load capacity. There was a 9 3/8” case that has a 3.250” bore size. While its appearance is very similar to a Ford 9 inch case, and will bolt into the same housing, it was a short term item from Ford and parts are no longer available for it.
STRANGE S-SERIES NODULAR 9 INCH CASE
Strange’s radial rib design significantly increases the rigidity of the case Strange Engineering’s own blend of nodular iron contains more bonding additive which increases material strength by 8-10%. Coupled with strategical reinforcements to the pinion support area, tail bearing pocket, and main caps, it exceeds the strength of the factory nodular case. The 3.062” bore case will fit all differentials and spools from 28 to 33 spline. The 3.250” will fit 35 spline differentials and spools, and 40 spline spools requiring a 3.250” bore case. The pricing allows an individual to purchase a new upscale case at a price of a used and fatigued factory part.
STRANGE PRO SERIES NODULAR IRON 9 INCH CASE
The Pro Series case is designed for maximum rigidity and strength where weight is not a primary concern. It can be identified by the stout horizontal and vertical ribs. As with all Strange engineering cases, “Strange” is embossed near the main cap area. Strange Engineering’s proprietary form of nodular iron is used, which is 8-10% stronger than typical nodular iron. The Pro Iron case design features reinforcements to two critical areas: the pinion support area and the tail bearing pocket. The main caps are chrome moly and utilize high strength adjuster nuts. The 3.062” bore case will fit all differentials and spools from 28 to 33 spline. The 3.250” will fit 35 spline differentials and spools, and 40 spline spools requiring a 3.250” bore case.