1956 Corvette: Service Bulletin: Instability Above 60 MPH

Subject:   Instability  Above 60 MPH
Model and Year:   1956 Corvettes (Serial Numbers Listed)
Source:  Chevrolet Technical Service Bulletin
Bulletin No:  DR #267
Section:   III
Date:  October 10, 1956


When an unstable condition exist above 60 MPH on 1956 Corvettes between Serial No. E56S 3175 and E56S 4156, the parts listed below should be installed:


Part Required Part No.
Steering Idler and 3rd Arm Assembly 1 3733215
Special Caster Shim (Round 1" Diameter)
Install between idler arm bracket
and crossmember to lower Idler Arm.
  • Use bolts, part no. 181639.
2 3733479
Special Shim (Tapered)
  • Install tapered shim with thick end
    to rear between frame side rails and
    front crossmember to increase caster.
  • Use bolts, part no. 181639 at rear.
2 3733477
Bolt 1-1/4" long 6 181639

Wheel Alignment (Revised)

All of the above applies to the 1957 Corvette.

Article ID: 962
Created: October 19, 2014
Last Updated: October 19, 2014

Online URL: https://www.corvetteactioncenter.com/tech/knowledgebase/article/1956-corvette-service-bulletin-instability-above-60-mph-962.html