scope:

Note: This commodity standard describes the requirements for engine oil pan and transmission bottom pan gaskets. The constructional and component features covered by this standard are described below. Do not use this document for applications outside the scope and 1.3 descriptions of this standard. 

Material Description. Table 1 describes the Class (A, B, F, or S) for engine (E) and/or transmission (T) elastomers meeting the designated temperature range and application. If no small capital letter is beside a Class, it applies to both engine and transmission. A hardness range for compounds is assigned by type using a numeric or alpha-numeric designation.

Symbols. 

Plastic and rubber parts shall be marked with a symbol to designate the type of material from which the part was fabricated for the purpose of collection and handling of parts for recycling.

Elastomer Marking Symbol. Mark rubber parts weighing more than 200 g per ISO 1629. Marking size and location per SAE J2332.

For Example: Polyacrylate >ACM<.

If practical, place the part number, your company Rubber Manufacturer's Association (RMA) code, cavity number and month date on the part. Characters shall be visible, and not in a location that adversely affects form, fit, or function.

Plastic Marking Symbol. Mark Plastic parts weighing more than 100 g per ISO 11469 Marking size and location per GM7400M.

For Example: Polyamide with glass fibers >PA-GF30<. 

Typical Applications. Gaskets or seals for lower engine (below engine block) and transmission bottom pan joints. O-rings and rubber coated metal gaskets for these applications are covered in other requirements.

Remarks.

Approved compounds properties for each type of elastomer are listed in Tables 3A, Table 4A, Table 5, and Table 6. Table values by type are a compilation of data from multiple approved compounds. GM Powertrain GM Engine only; ethylene acrylic rubber (AEM) is not permitted as part of the Assembly Fastening and Sealing Bill of Material (BOM). Properties from molded parts are found in Tables 3A_1, 3_B1, and 3_C1.

Silicone elastomer gasket compounds approved to this standard are safe for use near oxygen sensors (comply with GM9009P limit) and do not contribute to oil foaming (complies with 3.19.1.7). Parts made from silicone rubber approved to this standard are not post cured. Design is a critical factor for successful sealing when selecting silicone compounds. If properly protected and compressed, silicone is a satisfactory performer. See Appendix A.

Satisfactory GMW3155 test results are compound and design dependent.