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

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

View Instructions

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
  • Heavy Duty Reaction Shell
  • Enclosed Thrust Bearing
  • Custom Roller Clutch Race

May 14, 2006

Do Not Let Run-Out Make Problems for your 4L60-E

Gregg Nader

Topics: Diagnostics And Theory Rebuilding Tips Transmission GM 4L70-E Transmission 4L60-E Transmission 4L65-E Transmission

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February 22, 2016

Too Close For Comfort: Pinpointing 4L60-E Gear Train Assembly Problems

Steve Garrett

Topics: Transmission GM 4L70-E Transmission 4L60-E Transmission 4L65-E Transmission

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October 16, 2010

Transmission Report: SmartShell® and More

Topics: Transmission Report Newsletters Rebuilding Tips Diagnostics And Theory Transmission GM 4L70-E Transmission 4L60 Transmission 4L60-E Transmission 4L65-E Transmission

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July 14, 2016

Transmission Report: "See" More, Spend Less with Vacuum Testing

Topics: Transmission Report Newsletters Transmission

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June 05, 2013

Sonnax SmartShell® Video

Topics: Rebuilding Tips Transmission

Watch Now

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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.

Instructions