1996 GMC Jimmy Owner's Manual - Page 266

How to Check The proper fluid should be added if the level does not reach the bottom of the diaphragm when it's in place in the reservoir. See the instructions on the reservoir cap. 3ow to Check Lubricant Rear Axle When to Check and Change Lubricant Refer to the Maintenance Schedule to determinehow often to check the lubricant and when to change it. See "Scheduled Maintenance Services" in the Index. If the level is below the bottom of the filler plug hole, you'll need to add some lubricant. Add enough lubricant to raise the level to the bottom of the filler plug hole. 6-19