Tahoe 2WD V8-6.0L Hybrid (2008)
Drive/Propeller Shaft: Description and Operation
Propeller Shaft Description and Operation
The propeller shaft is a tube with universal joints at both ends that do not require periodic maintenance. The universal joints transmit power from the
transfer case, or from the transmission output shaft, to the differential.
Front Propeller Shaft Description
The front propeller shaft transmits rotating force from the transfer case to the front differential when the transfer case is engaged. The front propeller
shaft connects to the transfer case using a splined slip joint.
One-Piece Propeller Shaft Description
A one-piece propeller shaft uses a splined slip joint in order to connect the driveline to the transmission, or to the transfer case.
Propeller Shaft Phasing Description
The propeller shaft is designed and built with the yoke lugs, or the ears, in-line with each other. This produces the smoothest running shaft possible. A
propeller shaft that is designed with built-in yoke lugs in-line is known as in-phase. An out-of-phase propeller shaft often causes vibration. The propeller
shaft generates vibration from speeding up and from slowing down each time that the universal joint spins around. The vibration is similar to a person
snapping a rope and watching the wave reaction flow to the end. An in-phase propeller shaft is similar to 2 persons snapping a rope at the same time and
watching the waves meet and cancel each other. Cancelling the vibration produces a smooth flow of power in the drive line. All splined shaft slip yokes
are keyed in order to ensure proper phasing.
Universal Joint Description
The universal joint is connected to the propeller shaft. The universal joint consists of 4 caps with needle bearings and with grease seals. The caps and the
seals are mounted on the trunnions of a cross or of a spider. The bearings and the caps are greased at the factory. No periodic maintenance is required.
Two universal joints are used in a one-piece propeller shaft. Three universal joints are used in a two-piece propeller shaft. The bearings and the caps are
pressed into the yokes. The bearings and the caps are held in place with snap rings, except for 2 bearings on some models. These bearings on some
models are attached to the pinion flange of the differential. Universal joints handle the effects of various loads and of rear axle windup conditions during
acceleration and braking. The universal joint operation is efficient and safe within the designed angle variations. When the design angle is exceeded, the
operational life of the joint decreases.
Center Bearing Description
Center bearings support the driveline when using 2 or more propeller shafts. The center bearing is a ball bearing in a rubber cushion that attaches to a
frame crossmember. The manufacturer lubricates the bearing and seals the bearing. The cushion allows vertical motion at the driveline and helps isolate
the vehicle from vibration.
