For strength and resistance to fracture, the Sonnax input housing kit  made of high strength steel that is specially heat-treated with a very hard outer layer with a more ductile inner core. The feed holes are chamfered to reduce stress and the shaft is further processed by shot peening and deep cryogenic treatment.

Features

• Increased 3-4 clutch capacity by a redesigned apply plate allows for thicker steels and clutch options for increased torque capacity
  • Can accept (8) .067 in. frictions with (7).095 in.steels or (9) .062 in. frictions with (8) .077 in. steels
• Prevents 3-4 backing plate flex and distortion with zero-flex
• Treated Housing Resistant to Fatigue Failure
• Reinforced sleeve in steel input drum prevents breakage in shaft/spline area
• Eliminates 3-4 retaining ring blow-out by riding the unit of the snap ring and using 15-bolts to secure the anchor plate

Contents

• Modified Input Housing 
• PTFE Impregnated Rear Stator Support Bushing
• Overrun Piston Inner Seal
• Overrun Piston
• 3-4 Clutch Apply Plate
• (10) 3-4 Clutch Return Springs
• Overrun Piston Outer Seal
• Bolt-on Anchor Plate
• Overrun Piston Outer Seal
• (15) Socket Head Cap Screws 

Note: 

• Requires '91-later 3-4 apply ring
• Requires '97-later ring gear
• Requires '97-later dual-cage return spring
• Requires '87-later forward backing plate
• Requires '97-later stamped steel forward piston
• Cannot be used with aluminum forward piston or Sonnax billet forward piston 852-77764-01