This is an "Original" (not a reprint) bulletin for Chevrolet mechanics covering items on the NEW 1957. It was issued June 1957.  This was the first year that Positractions  were installed as an option on Chev.  passenger cars. The first ones were far from perfect. I remember the first one we received, we had to take off the transport with a wrecker because it was locked up and it took 4 weeks to get the parts, This publication covers the revised servicing requirements including operating characteristics. (clunk, slack etc.)  In addition to the Positraction, this 4 page bulletin covers other areas on the 57s listed below:

Positraction Rear Axle Clutch Arrangement

Corvette Spark Plug Changes

Fuel Injection Pump Drive Shaft Installation

Power Steering Noise  

Six Cylinder Engine Choke Setting 

Valve and Spring Height Correction

New Process Five Speed Transmission Cover

Turboglide Valve Body Part Number....

Passenger Car Body Identification Plate Relocated     

Six Cyl. Engine Choke Setting Changed

Air Conditioning Hose Interference

This original bulletin is in very good condition with some slight soil & yellowing on the cover. inside & back very good. See Photos.