1958 Corvette: Service Bulletin: Positraction Axle Operation and Service

Subject:   Positraction Axle Operation and Service
Model and Year:   1958 Passenger Cars and Trucks with Positraction
Source:  Chevrolet Technical Service Bulletin
Bulletin No:   DR #356
Section:   IV
Date:    April 29, 1958



Under some operating conditions where one rear wheel is on an excessively slippery surface and the opposite wheel is on a good traction surface, it may be necessary to lightly apply the parking brake (usually 3 or 4 notches) to produce enough resistance to the spinning wheel to cause axle lock-up.

Lock-up is independent of acceleration; therefore, light throttle application on starting is recommended to provide maximum traction by preventing "break away" of the non-slip wheel.


The Positraction unit can be effectively tested for correct operation by placing one rear wheel on good dry pavement and the other on ice, mud, grease, etc.

It can be determined where or not the non-slipping wheel is providing pulling power.  The procedure can then be repeated with opposite wheels on the dry and slippery surfaces.

CAUTION :  The warning posted in the luggage compartment regarding operation of the unit while o a jack should not be interpreted as a means of testing.  Its only intention is to point out that a possibility does exist that the axle could lock-up under certain conditions and force the vehicle off the jack.



  Dimensions Part No.
Standard .092" - .097" *
Oversize .096" - .101" 531403

*  Part of unit #3745311.

Article ID: 1070
Created: January 2, 2015
Last Updated: January 2, 2015

Online URL: https://www.corvetteactioncenter.com/tech/knowledgebase/article/1958-corvette-service-bulletin-positraction-axle-operation-and-service-1070.html