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Sonnax Smart Shell kit

Pricing: $115.00

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  • Heavy Duty Reaction Shell
  • Enclosed Thrust Bearing
  • Custom Roller Clutch Race 
  • Stops Spline Stripping
  • Prevents Hub Breakage
  • Eliminates Planet Bearing Failure
  • Fits 4L60, 4L60-E, 4L65-E, 4L70-E

SmartShell® Heavy-Duty Reaction Shell Kit fixes sun gear shell problems with BRAINS, not just brawn.

Bulky aftermarket shells always fall short when splines continue to strip and the shells break under stress. 

A chronic problem with both OE and thicker aftermarket shells is failure of the rear planetary bearing. 

From your daily jobs to extreme builds, the patented SmartShell is the only way to prevent shell failure AND protect the bearing.

Stripped or cracked shells in GM 700R4, 4L60, 4L60-E, 4L65-E and 4L70-E units are a common problem, but strengthening the shell alone does nothing to address the equally common problem of a failed rear planet captured bearing.

Protecting the Planetary Bearing

In the OE sun gear shell, the thrust load passes from the shell through the sun gear, then overloads the small captured planetary bearing. To protect this bearing, Sonnax took the smart approach and replaced the OE black plastic washer with a large thrust bearing and roller clutch race. This re-routes the thrust load directly to the carrier, completely bypassing the delicate bearing.

Strengthening the Shell

The SmartShell avoids the substantially increased weight found in other aftermarket shells. The Sonnax approach to improving the shell includes reinforcing the hub area with a laser-beam-welded collar. A final machining process after welding ensures precision alignment. The SmartShell splines undergo an advanced machining and heat-treating process, and the lugs that engage the drum are heat-treated, as well, to avoid flaring.



Shipping Information

  • Item Requires Shipping
  • 10.0 lbs.
  • W12.0000” x H12.0000” x L12.0000”

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