700R4,4L60, 4L60-E, Reinforced Input Housing Kit with Heavy Duty Input Shaft

Sonnax reinforced input housing kits come with input shaft assemblies, input drum reinforcement sleeves, overrun pistons, and seals to be a great upgrade for high performance and heavy-duty applications. Stronger than OE shafts, these kits are made of specially heat-treated steel with very hard outer layers and a more ductile inner core for strength and resistance to fracture. The feed holes are chamfered to reduce stress, and the shaft is further processed by shot peening and deep cryogenic treatment, while the reinforcement sleeve installed on the housing strengthens the aluminum splines, which otherwise would be prone to cracking. The custom-manufactured overrun pistons are designed to be used only with a stamped steel forward piston, eliminating the need to use OE cast forward pistons or aftermarket billet forward pistons. Choose the strength of Sonnax reinforced input housing kits for your transmission rebuild.