Description
4L60E / 4L65E / 4L70E Smart-Tech® Input Housing Kit with Heavy Duty Input Shaft, Sonnax 77733-12KB.
Sonnax Smart-Tech input housing kit 77733-12KB 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. The improved housings have precisely cut splines that reliably retain and seal the input shaft.
Smart-Tech input housing kit with heavy duty input shaft 77733-12KB fits 300mm torque converter, reluctor-style units. The shaft is manufactured from 300M ultra high-strength steel for exceptional toughness and resistance to fracture. Both the housing and shaft also are available separately.
- 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
- The new housing is designed to optimize input shaft fitment and is upgraded for greater resistance to fatigue failure.
- Steel reinforcement sleeve prevents breakage in the spline area
- Custom backing plate replaces OE retaining ring to eliminate risk of blowout
- High-strength 300M shaft
Requires ’91-later 3-4 apply ring; requires ’87-later ring gear; requires ’97-later stamped steel forward piston. Cannot be used with aluminum forward piston or Sonnax billet forward piston 77764-01.
- Smart-Tech® Input Housing with Heavy Duty Input Shaft
- 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)
