TM-5-3805-254-14-P-2

TRUCK, DUMP, 20 TON, 6X4, ON-OFF HIGHWAY 71,000 GVW, IHC MODEL F-5070 (CCE)

TECHNICAL MANUAL; OPERATOR’S, ORGANIZATIONAL, DIRECT SUPPORT, GENERAL SUPPORT AND DEPT MAINTENANCE MANUAL (INCLUDING REPAIR PARTS INFORMATION AND SUPPLEMENTAL MAINTENANCE INSTRUCTIONS)

JUNE 1980

TM-5-3805-254-14-P-2 - Page 600 of 894

TRUCK SERVICE MANUAL

PROPELLER SHAFT

General

Fig. 4.

Universal Joint Speed Fluctuations

UNIVERSAL JOINT CANCELLATION

A single universal joint operating between two shafts

at a given angle will not turn at an even and constant

speed; that is to say that, although the speed of the

driving shaft is constant, the driven shaft speed is going

to fluctuate up and down.

During the first 90 degrees of rotation, the forward

universal joint speed will increase, Fig. 4.

From 90

degrees to 180 degrees the speed will decrease to again

match the driving shaft speed.

This sequence is again

repeated respectively from 180 degrees to 270 degrees

and from 270 degrees to 360 degrees.

This speed

fluctuation is known as torsional excitation (winding up

and unwinding) of the propeller shaft.

If two joints are placed in the drive line, one at each

end of the propeller shaft, having equal working angles,

the rear joint will provide the inverse condition of the

forward joint.

In other words, the rear joint will slow down

by the same amount that the forward joint speeds up,

resulting in joint cancellation.

The driving and driven

shafts will turn at constant and identical speeds.

PROPELLER SHAFT PHASING

Propeller shaft phasing is the relative positioning of

one yoke or flange with another on the same shaft within

a 360 degree revolution.

Correct phasing is equally important when compared

with other factors governing proper drive line operation.

Fig. 5.

Propeller Shaft in Phase

593