Bushings

ALLISON 1000 & 2000 PRODUCT FAMILIES GENERAL INSPECTION GUIDELINES FOR BUSHINGS

Bushing wear is strongly influenced by the quantity and condition of the lubricant. A. Bushing

A. Inspect bushings for wear beyond service limits. Replace any bushing which is excessively worn. Inspect bushings for discoloration and surface damage due to lack of lubrication. Replace any bushing which is damaged.

General Bushing Information

Mechanically, bushings are the simplest type of journal bearing and are often referred to as “plain” bearings. A bushing is simply a sleeve of bearing material, such as bronze or aluminum, in which a component rides. Bushing wear is strongly influenced by the quantity and condition of the lubricant. Bushing bearing surfaces are sometimes grooved to better distribute lubrication across the bearing surface. Some bushings are susceptible to material leaching. This can be caused by oxidized oil that has turned acidic combined with heat and mechanical loading. The TAN (Total Acid Number) of the transmission oil should not change by more than 3 from the baseline (new fluid) TAN. Changing transmission oil per recommended change intervals or based on a successful oil sampling program will help prevent material leaching.