Wrangler 4WD L4-150 2.5L VIN P MFI (1998)
Drive/Propeller Shaft: Description and Operation
Propeller Shafts
PROPELLER SHAFTS
The function of a propeller shaft is to transmit power from one point to another. The shaft is designed to send torque from the transmission and
transfer case to the drive axles.
The propeller shaft must operate through constantly changing relative angles between the transmission and axle. It must also be capable of changing
length while transmitting torque. The axle rides suspended by springs in a floating motion. The propeller shaft must be able to change operating angles
when going over various road surfaces. This is done through universal joints, which permit the propeller shaft to operate at different angles. The slip
joints (or yokes) permit contraction or expansion.
Tubular propeller shafts are balanced by the manufacturer with weights spot welded to the tube.
The propeller shaft is designed and built with the yoke lugs in line with each other which is called zero phasing. This design produces the smoothest
running condition, an out-of-phase shaft can cause a vibration.
Before undercoating a vehicle, the propeller shaft and the U-joints should be covered to prevent an out-of-balance condition and driveline vibration.
CAUTION: Use original equipment replacement parts for attaching the propeller shafts. The specified torque must always be applied when
tightening the fasteners.
