GMNA GM209M PDF

This document covers the requirements of rubber (55 to 80 hardness) used for fastener isolator grom-mets. Test requirements for approved compounds are intended to permit usage in the described tem-perature and engine fluid exposure environment& Currently only Class B compounds are defined. Sili-cone (VMQ) grommets not meeting Table 1 volatility limits can't be used in internal, direct oil exposed applications (e.g. PCV vent grommets or center bolt grommets on engine covers). These compounds will be designated with a grade 1 restriction (see 7.1). For all other grommets, see GM221 M.

Material Description. The term grommet — used in this document — is as defined by the GM Corporate Manual of Functional Names Glossary. It is an item of any peripheral shape having flanges or a groove(s) on its outer perimeter to provide a self-retaining characteristic when inserted in a hole. The grommet is designed to insulate or protect an item passing through it or used as a mount or seal for another part.

Table 1 (p. 6) contains requirements for all grommet compound& Specific applications are assigned a type based on nominal micro-hardness (International Rubber Hardness Degree). Table hardness will vary slightly as dictated by approved compounds. Type is subdivided into class (A-C) depending on the tem-perature and fluid resistance requirements. A spe-cial grade 1 restriction designation is applied solely to high (more than 1%) volatile silicone grommet com-pound(s).

The continuous functional temperature range is defined by ASTM D1329 TR10 and the upper tem-perature limit (CUTL) by SAE J2236.

Compound Nomenclature. Identify your type using ASTM D1418 or ISO 1629. 1.1.4 All Type 1, Class B materials are silicone (VMQ). Other materials may be used if the need arises.

All prints designating GM209M before January 2002 were Type 1 (class B) silicone compounds. Previous print references to Type 1A are now Type 2.

Symbol. The part molder shall identify the pro-duction material for recycling or disposal according to SAE J2332 or VDA 260.

For Example: Silicone >VMQ