Q: What is the purpose of a driveshaft and Universal Joint and how does it function in a Lincoln Navigator?
A: The driveshaft sends engine power to the rear axle through the transmission. At either end of a driveshaft universal joints are used. Although many U-joints are single-cardan type, some 4WD models have double-cardan U-joints. A slip yoke is located at the front of a rear driveshaft, and it connects to a Differential by means of a flange yoke. Front driveshafts on 4WD have a slip yoke on each end. The only time a driveshaft may need attention is when the universal joints wear out and need replacing as they are serviceable items which require little maintenance otherwise. Additionally, the driveshaft should be inspected for damage during service procedure and cleaned of any debris that might be present in order for it to function properly again as well.
Q: How to remove and install a Lincoln Navigator's driveshaft?
A: Turn off air suspension system if equipped. Raise vehicle on jackstands, place transmission in Neutral, block front wheels. Mark relationship between rear driveshaft and differential pinion flange. Remove rear universal joint bolts and center bearing support bracket bolts if applicable. Lower and remove rear driveshaft, protect extension housing. Inspect and replace seals if necessary. Check center bearing for two-piece driveshafts. Install in reverse, align marks, tighten bolts. For front driveshaft on 4WD models, remove shield, mark relationships, remove bolts, lower and remove driveshaft. Inspect and replace seals if needed. Install front end to front axle differential pinion flange, attach rear end to transfer case output shaft companion flange, secure shield. Remove jackstands, lower vehicle, reactivate air suspension if applicable.