1994 Chevrolet Astro Owner's Manual - Page 242

Rear Axle When to Check and Change Lubricant Refer to the Maintenance Schedule to determine how often to check the lubricant and when to change it. See "Scheduled MaintenanceServices" in the Index. How to Check Lubricant If the level is below the bottom of thefiller plug hole, you'll need to add somelubricant. Add enough lubricant to raise the level to the bottom of thefiller plug hole. ...I... What to Use Refer to the Maintenance Schedule to determine what kind of lubricant to use. See "Recommended Fluids andLubricants" in the Index. All- Wheel IDrive If you have an all-wheel drive vehicle, be sure to perform lubricant the checks described in this section. However, they have two additionalsystems that need lubrication. Transfer Case When to Check Lubricant Refer to the Maintenance Schedule to determine how often tocheck the lubricant. See "Periodic MaintenanceInspections" in the Index. 6-24