37911HP - INPUT SHAFT & DRUM (TH700/4L60) HI PERF

# 37911HP

Hi Performance Input Shaft & Drum

INPUT SHAFT & DRUM (TH700/4L60) HI PERF

This item is ordered on demand and is subject to supplier availability.

Please Contact Us to confirm Pricing and ETA

Fits '85-later 298mm units with 30-spline input shaft. For '82-84 298mm units with 27-spline input shaft, converter and stator shaft will need to be updated to '85-later design.

Warning:
Earlier versions of this kit required an aluminum forward piston. It is recommended to follow the specific instructions provided during assembly to avoid a mismatch of parts.

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. The unique Sonnax Smart-Tech housing design makes room for a taller clutch pack anchored in place by a stronger backing plate, making it the only way to increase clutch capacity and protect against destructive heat. Numerous other improvements to the housing ensure maximum durability and protection against failure in higher horsepower, higher pressure applications.

This Smart-Tech input housing kit with heavy duty input shaft fits 298mm torque converter units. The high-strength shaft features many unique refinements available only from Sonnax, including a unique design that protects against failure from stress cracks. 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
Treated housing is 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

Note:
Requires '91-later 3-4 apply ring; requires '87-later ring gear; requires '97-later stamped steel forward piston; requires '97-later dual-cage return spring; requires '87-later forward backing plate. Cannot be used with aluminum forward piston or Sonnax billet forward piston # 37586. See instructions for further detail.

Contents: