Universal Joint Angle; Runout Specifications; Maximum Angles And Engine Speed; Service Procedures - Jeep Wrangler 1997 Manual

TJ
DIAGNOSIS AND TESTING' ,(Continued)
RF488
Fig. 6 Two Clamp Screws At The Same Position
INCH
Fig. 7 Clamp Screws Separated
RUNOUT SPECIFICATIONS
RF489
Front of shaft . . . . . . . . . . . . . . . . . . ' ,0.010 in . (0.25 mm)
Center of shaft . . . . . . . . . . . . . . . . . ' ,0.015 in . (0.38 mm)
Rear of shaft . . . . . . . . . . . . . . . . . . 1 0.010 in . (0.25 mm)
NOTE : Measure front/rear runout ap roximately 3 inches
(76 mm) from the weld seam at each (nd of the shaft tube
for tube lengths over 30 inches . Uncle 30 inches the max.
runout is 0.20 inch for full length of th - tube.
I
SERVICE PROCEDURES
UNIVERSAL JOINT ANGLE
J9116-15
INFORMATION
When two shafts come together at any common
joint, the bend that is formed is ailed the operating
angle. The larger the angle, the larger the amount of
DIFFERENTIAL AND DRIVELINE 3-5
acceleration and deceleration of the joint. This speed-
ing up and slowing down of the joint must be can-
celled to produce a smooth power flow. This is done
through phasing and proper universal joint working
angles.
A propeller shaft is properly phased when the yoke
ends are on the same plane or in line . A twisted shaft
will throw the yokes out of phase and cause a notice-
able vibration .
When taking universal joint angle measurements
or checking phasing with two piece shafts, consider
each shaft separately. On 4WD vehicles, the front
shaft input (pinion shaft) angle has priority over the
caster angle.
Ideally the driveline system should have;
" Angles that are in equal or opposite within 1
degree of each other
" Have a 3 degree maximum operating angle
" Have at least a 1/2 degree continuous operating
(propeller shaft) angle
Engine speed (rpm) is the main factor though in
determining maximum allowable operating angles.
As a guide to maximum normal operating angles
refer to the chart listed (Fig. 8).
PROPELLER SHAFT MAX . NORMAL
R . P .M .
OPERATING ANGLES
5000
4500
4000
4°
3500
5°
3000
2500
7°
2000
8°
1500
11°
3°
3°
5-
J9316-4
Fig. 8 Maximum Angles And Engine Speed
INSPECTION
Before measuring universal joint angles, the
following must be done.
" Inflate all tires to correct pressure
" Check angles in the same loaded or unloaded
condition as when the vibration occurred . Propeller
shaft angles will change according to the amount of
load in the vehicle. Always check angles in loaded
and unloaded conditions.
" Check the condition of all suspension compo-
nents and verify all fasteners are torqued to specifi-
cations.
" Check the condition of the engine and transmis-
sion mounts and verify all fasteners are torqued to
specifications .
PROPELLER SHAFT ANGLE MEASUREMENT
To accurately check driveline alignment, raise and
support the vehicle at the axles as level as possible .