The front axle assembly used on most 4wd models covered by this repair guide utilizes a central disconnect type front axle/transfer case system which allows shifting in and out of 4wd when the vehicle is moving under most driving conditions. The axle has an aluminum carrier which includes a vacuum activated center lock feature.
The axles on the Bravada and Typhoon are designed for full-time four wheel drive and therefore are not equipped with a disengagement feature. With this one exception, the Bravada, Typhoon and standard 4wd front axle assemblies are very similar.
The drive axles employ completely flexible assemblies which consist of inner and outer constant velocity (CV) joints connected by an axle shaft. The inner CV joint is a "tri-pot" design, which is completely flexible and can move in and out. The outer CV joint is a "Rzeppa" design which is also flexible but cannot move in or out.
For more information on front axle identification, please refer to General Information & Maintenance in this repair guide.