Semi-Truck Electric Shift Unit Design Improvement

Date of Defense


First Advisor

Dr. Daniel Kujawski

Second Advisor

Dr. Iskender Sahin

Third Advisor

Dr. Jerry Hamelink


Eaton Corporation of Galesburg, Michigan is the engineering world head quarters for truck axle design. One such axle is the Eaton two-speed axle. Eaton two-speed axles are driver-controlled by means of a shift unit operated from the vehicle cab. These shift units are activated by either air or electric power, depending on the convenient source in the chassis. The electric shift units were not meeting the standards for life expectation of such a unit. Therefore, it was the desire of Eaton Corporation to have an in-depth study performed of the shift unit and its modes of failure to aid in redesign of the product. The results of the study revealed the main causes of failure to be in the circuit board, shift fork seal,and the motor mounting. Leakage in the shift unit led to corrosion of the internal components and more importantly, the circuit board. An alternative set of designs was investigated to reduce leakage and eliminate binding in the motor. These design alternatives included a redesigned motor mount and a repositioned shift fork seal.


Eaton Corporation claims proprietary rights to the material disclosed hereon. This drawing and/or technical information is issued in confidence for engineering information only and may not be reproduced or used to manufacture anything shown or referred to hereon without direct written permission from Eaton Corporation to the user. This drawing and/or technical information is the property of Eaton Corporation and is loaned for mutual assistance to be returned when its purpose has been served. Duplication of this drawing and/or technical information is strictly prohibited.

Access Setting

Honors Thesis-Campus Only

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