ASTM D4950 Standard Classification and Specification for Automotive Service Greases
4. Performance Classification
4.1 Automotive service greases are classified into two general groups. Those designated with an "L" prefix (chassis greases) are intended for the service lubrication of ball joints, steering pivots, universal joints, and other chassis components as designated by the equipment manufacturer. Those designated with a "G" prefix are intended primarily for the service lubrication of wheel bearings. These groups are further subdivided into categories with intended service applications as follows:
4.1.1 LA - Service typical of chassis components and universal joints in passenger cars, trucks, and other vehicles under mild duty only. Mild duty is encountered in vehicles operated with frequent relubrication in noncritical applications.
4.1.2 LB - Service typical of chassis components and universal joints in passenger cars, trucks, and other vehicles under mild to severe duty. Severe duty is encountered in vehicles operated under conditions which might include prolonged relubrication intervals, or high loads, severe vibration, exposure to water or other contaminants, etc.
4.1.3 GA - Service typical of wheel bearings operating in passenger cars, trucks, and other vehicles under mild duty. Mild duty is encountered in vehicles operated with frequent relubrication in noncritical applications.
4.1.4 GB - Service typical of wheel bearings operating in passenger cars, trucks, and other vehicles under mild to moderate duty. Moderate duty is encountered in most vehicles operated under normal urban, highway, and off-highway service.
4.1.5 GC - Service typical of wheel bearings operating in passenger cars, trucks, and other vehicles under mild to severe duty. Severe duty is encountered in certain vehicles operated under conditions resulting in high bearing temperatures. This includes vehicles operated under frequent stop-and-go service (buses, taxis, urban police cars, etc), or under severe braking service (trailer towing, heavy loading, mountain driving, etc.).
5. Performance Description
5.1 The performance characteristics of the several categories of automotive service greases are described as follows:
5.1.1 LA - The grease shall satisfactorily lubricate chassis components and universal joints where frequent relubrication is practiced (at intervals of 3200 km or 2000 miles or less for passenger cars). During its service life, the grease should resist oxidation and consistency degradation and protect the chassis components and universal joints from corrosion and wear under lightly loaded conditions. NLGI 2 consistency greases are commonly recommended, but other grades may also be recommended. (NLGI Consistency Numbers are shown in Table X1.1 of the appendix.)
5.1.2 LB - The grease shall satisfactorily lubricate chassis components and universal joints at temperatures as low as -40 °C and at temperatures as high as 120 °C over prolonged relubrication intervals (more than 3200 km or 2000 miles for passenger cars). During its service life, the grease should resist oxidation and consistency degradation while protecting the chassis components and universal joints from corrosion and wear even when aqueous contamination and heavily loaded conditions occur. NLGI 2 consistency greases are commonly recommended, but other grades may also be recommended.
5.1.3 GA - The grease shall satisfactorily lubricate wheel bearings over a limited temperature range. Many products of this type are limited to bearing temperatures of (-20 to 70) °C. No additional performance requirements are specified for these greases.
5.1.4 GB - The grease shall satisfactorily lubricate wheel bearings over a wide temperature range. The bearing temperatures may range down to -40 °C, with frequent excursions to 120 °C and occasional excursions to 160 °C. During its service life, the grease shall resist oxidation, evaporation, and consistency degradation while protecting the bearings from corrosion and wear. NLGI 2 consistency greases are commonly recommended, but NLGI 1 or 3 grades may also be recommended.
5.1.5 GC - The grease shall satisfactorily lubricate wheel bearings over a wide temperature range. The bearing temperatures may range down to -40 °C, with frequent excursions to 160 °C and occasional excursions to 200 °C. During its service life, the grease shall resist oxidation, evaporation, and consistency degradation while protecting the bearings from corrosion and wear. NLGI No. 2 consistency greases are commonly recommended, but NLGI No. 1 or No. 3 grades may also be recommended.
6. Performance Requirements
6.1 The greases identified by these categories shall conform to the requirements listed in Table 1 and Table 2. A guide to the requirements of all the grease categories is given in Table X1.2 of the appendix.
6.2 The consistency requirements in Table 1 and Table 2 cover NLGI Consistency Numbers 1 through 3 (see Table X1.1). However, because the equipment manufacturers recommendations might be more restrictive, it is recommended that grease containers display the consistency number as well as the grease category designation.
6.3 Some grease makers market products under the term multipurpose grease, implying or stating that such products are suitable for both chassis and wheel bearing lubrication. To comply with this specification, greases intended and suitable for both chassis and wheel bearing lubrication might carry such designation but, in addition, shall carry both an "L" and "G" designation (LB-GC, for example) and conform to the appropriate requirements listed in Table 1 and Table 2.
7. Keywords
7.1 automotive grease categories; automotive service grease; chassis grease; multipurpose automotive grease; NLGI chassis and wheel bearing service classification; NLGI grease classification; wheel bearing grease
