Info - Correct Vehicle Application for Eaton NoSpin Differentials

This bulletin is being issued to address the concerns of customers, fleets and dealers regarding axle shaft breakage on medium duty commercial vehicles equipped with Eaton® NoSpin differentials (RPO G86).

This NoSpin differential allows the vehicle to perform as if the axle shafts were completely locked. Both wheels turn at the same speed. If one wheel loses traction or leaves the ground, both shafts stay locked. On turns, a driven clutch in the NoSpin assembly will disengage the outside wheel until the speeds equalize.

A metallurgical examination of many returned axles over the last several years has revealed that the cause of the vast majority of the failures has been vehicle misapplication.

Engineering has recently taken steps to limit RPO G86 availability for the current medium duty Conventional and tilt cab product line. A completely new torque sensitive limited-slip differential (RPO G80) has been released for November, 2001 introduction. NoSpin differentials will not be offered on the new 2003 medium duty product line.

The Engineering Data Book now specifically states that "NoSpin differentials are not recommended on vehicles that are primarily used in on-highway service. It is recommended that tandem axle vehicles should be operating a minimum of 90% off road to mandate the use of a NoSpin differential."

Eaton® has an exclusion on axle shaft warranty when used with NoSpin differentials. Failures of axle shafts when used with NoSpin differentials are not covered under Eaton's warranty.

Failures of NoSpin axle shafts on vehicles primarily used in on-highway applications are considered to be misapplied. These subsequent failures do not represent a defect in material or workmanship for which General Motors would be responsible. In addition, these failures do not cause loss of control of the vehicle.