1953 - 1955 Corvette: Service Bulletin: Distributor Dust Contamination

Subject: Distributor Dust Contamination
Model and Year: 1953-1962 6-Cylinder Engines
Source: Chevrolet Service Bulletin
Bulletin Number: DR #549, Section VIy
Date: August 3, 1962


Under extremely dusty operating conditions such as encountered in off-highway driving, it may be necessary to provide additional protection against distributor dust contamination on 6-cylinder equipped vehicles.  Production changes and additional field modifications which will extend the service life of distributor contact points, rubbing block and cam in dusty areas are outlined on the reverse side.

1953-62 216, 235 & 261 L-6 ENGINES

PRODUCTION CHANGE - In late 1961, the two (2) 5/16" diameter vent holes in the bottom of the distributor housing were replaced with one (1) 1/4" hole to reduce the possibility of dust entry.  This was a running change with no new part number involved.

FIELD CORRECTIONS - Vending area on early distributors may be reduced by plugging the two existing 5/16" holes with a suitable substance such as plastic body solder.  A 1/8" hole in one of the plugs must be provided to allow escape of the ozone gas generated during distributor operation.

CAUTION:  Failure to provide a 1/8" vent will result in premature ozone corrosion of all metal surfaces.  Care should be taken not to foul the advance mechanism by pushing solder inside the distributor.

A Server only Dust Shield, Part Number 1945388, is available to provide additional protection for all 1953-62 models. This shield is easily installed by removing the distributor cap and placing shield over the contact points as shown on the right.


PRODUCTION CHANGE - On late 1962 distributors, the two (2) 1/4" diameter hols in the bottom of the distributor housing have been eliminated.  Sufficient venting area is provided by the opening around the vacuum advance control.

FIELD CORRECTIONS - Both vent holes in the distributor housing may be plugged with plastic body solder.  Care should be taken not to foul the advance mechanism by using solder inside the distributor.


1945388 - Distributor Dust Shield 1953-62 216, 235, 261 L-6

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.

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Article ID: 782
Created: August 3, 2014
Last Updated: August 3, 2014
Author: Rob Loszewski

Online URL: https://www.corvetteactioncenter.com/tech/knowledgebase/article.php?id=782