4L60, 4L60-E, 4L65-E, 4L70-E

SmartShell® Heavy Duty Reaction Shell Kit
Part No. 77749-02K

View Instructions Find a Distributor

Solves Multiple Problems in All Performance Applications

In GM 4L60, 4L60-E, 4L65-E and 4L70-E units, 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 daily jobs to extreme builds, the Sonnax SmartShell heavy-duty reaction shell kit 77749-02K is the only way to prevent shell failure AND protect the bearing.

The SmartShell avoids the weight found in traditional, heavy-duty aftermarket shells thanks to a unique combination of improved design and manufacturing for a super strength shell that's only slightly bulkier than OE. To prevent thrust loads from overwhelming the captured planetary bearing, the SmartShell features a larger bearing and custom roller clutch race. These parts re-route thrust loads through the carrier, completely bypassing the delicate bearing.

  • Stops spline stripping
  • Prevents hub breakage
  • Eliminates planetary bearing failure

  • 4L60, 4L60-E, 4L65-E, 4L70-E SmartShell® Heavy Duty Reaction Shell Kit 77749-02K
  • 4L60, 4L60-E, 4L65-E, 4L70-E SmartShell® Heavy Duty Reaction Shell Kit 77749-02K details
  • 4L60, 4L60-E, 4L65-E, 4L70-E SmartShell® Heavy Duty Reaction Shell Kit 77749-02K details
  • 4L60, 4L60-E, 4L65-E, 4L70-E SmartShell® Heavy Duty Reaction Shell Kit 77749-02K details
  • 4L60, 4L60-E, 4L65-E, 4L70-E SmartShell® Heavy Duty Reaction Shell Kit 77749-02K details
  •  

Fix sun gear shell problems with BRAINS, not just brawn.

Stronger, Durable Shell

Shell Breakage

Stripped Splines

The SmartShell avoids the weight found in traditional, heavy-duty aftermarket shells. A unique combination of improved design and manufacturing delivers a super strength shell that's only slightly bulkier than OE.

 

Unbeatable Bearing Protection

Damage to the Small Captured Bearing

Residual Planetary Damage

To prevent thrust loads from overwhelming the captured planetary bearing, the SmartShell features a larger bearing and custom roller clutch race. These parts re-route thrust loads through the carrier, completely bypassing the delicate bearing.