The fluid level in a transfer case should be checked at recommended intervals. To check the lubricant level, remove the transfer case fill plug, which is normally located on the side or rear of the case. The lubricant should be almost even with the fill hole. If required, add the recommended type and amount.

The first indication of trouble within a transfer case, as with other components of the power train, is usually noisy operation. If an operator reports trouble, make a visual inspection before removing the unit from the vehicle. Check for such things as oil level, oil leakage, and water in the oil.

Figure 5-32.- Positive traction transfer case operation.

Make sure the shift lever linkages are not bent or improperly, lubricated. This will make it hard to shift or, in some cases, impossible to shift. Make sure other possible troubles, such as clutch slippage, damaged drive shaft, and damaged axles, have been eliminated.

Worn or broken gears, worn bearings, and excessive end play in the shafts can cause noisy operation. When transfer case service is required, follow the procedures outlined in the service manual. It will give directions for repairing the particular make and model.