Smart-Tech Input Housing Kit with Heavy Duty Input Shaft
Limitations of the GM 4L60 series OE input housing are the root cause of 3-4 burnup in performance applications. The weak OE backing plate flexes during clutch apply, allowing heat to build up unevenly within the clutch pack’s limited space. Stop the flex and you stop 3-4 clutch failure. Sonnax Smart-Tech input housing kit 7773311KA makes room for a taller clutch pack anchored in place by a stronger backing plate — the most reliable way to increase clutch capacity and protect against destructive heat.
To avoid the problems found with older, OE housing designs, Sonnax starts with the latest production, new housings from GM. These improved housings have splines for the input shaft that are cut at minimum spec for reliable shaft retention and sealing. The housings also benefit from added material for a thicker, more consistent cross-section that protects against breakage.
Smart-Tech input housing kit with heavy duty input shaft 7773311KA fits 300mm non-reluctor style units. The high-strength shaft features many unique refinements available only from Sonnax, including a unique design that protects against failure from stress cracks.
Features & Benefits:
Physically larger clutch pack area for increased 3-4 clutch capacity without sacrificing clutch durability. Use your choice of:
Eight .067" frictions with seven .095" steels
Nine .062" frictions with eight .077" steels
Anchored backing plate keeps clutches parallel to stop the flexing and distortion that leads to heat build-up
100% New housing optimizes input shaft fitment and is further upgraded for significantly more resistant to fatigue failure
Steel reinforcement sleeve prevents breakage in the spline area
Custom backing plate replaces OE retaining ring to eliminate risk of blowout
Kit Contents:
Smart-Tech Input Housing with 300mm Non-Reluctor Style Input Shaft Assembly
Bolt-on Anchor Plate
3-4 Clutch Apply Plate
3-4 Clutch Return Springs (10)
Input Drum Reinforcement Sleeve installed
Overrun Piston
Overrun Piston Inner Seal
Overrun Piston Outer Seal
PTFE Impregnated Rear Stator Support Bushing
Socket Head Cap Screws (15)
Videos
Eliminate 3-4 Clutch Failure with the Smart-Tech® Input Housing
Your Guide to a Sonnax 4L60/E High Horsepower Level 3 Transmission Build
Additional Resources