Chevrolet 1980 Light Duty Truck Service Manual page 192

3B1-8 STEERING LINKAGE
1. Check the total rotation of the tie rod assembly
using the following procedure:
a. Lubricate inner and outer tie rod ends.
b. Attach vise grip pliers to the outer tie rod end.
c. Rotate outer tie rod end counterclockwise (up) to
maximum position. Attach bevel protractor as shown in
Figure 3B1-9. Center protractor bubble indicator and
record reading.
d. Rotate tie rod end clockwise (down) to maximum
position. Center protractor bubble indicator and record
reading.
e. Compare protractor readings obtained in Speps c and
d. Total rotation of tie rod assembly should measure at least
35°.
f. If rotation is less than 35°, loosen one tie rod sleeve
clamp and rotate both tie rod ends to their maximum limit
both ends must be rotated in the same direction
g. Tighten tie rod clamp and again rotate both ends to
their maximum limits, repeating Steps c and d. This recheck
of total rotation will result in a minimum of 35° travel.
h. After obtaining the correct amount of rotation (35°
or greater), position the outer tie rod end approximately
midway in this travel.
If rotating checks, outlined above, reveal a rough or
lumpy feel, the inner or outer tie rod end assembly may have
excessive wear and should be replaced.
If all of the above mentioned conditions are met, proper
tie rod installation is assured.
RELAY ROD
Removal
1. Raise vehicle on hoist.
2. Remove inner ends of the tie rods from relay rod
as described under "Tie Rod-Removal".
3. Remove the nuts from the pitman and idler arm ball
studs at the relay rod.
4. Remove the relay rod from the pitman and idler
arms by tapping on the relay rod ball stud bosses with a
hammer, while using a heavy hammer as a backing (Fig.
3B1-7).
5. Remove the relay rod from the vehicle.
Installation
NOTICE: See the NOTICE on page 1 of this section
regarding the fasteners referred to in steps 2 and 3.
1. Make sure that threads on the ball studs and in the
ball stud nuts are clean and smooth. If threads are not clean
and smooth, ball studs may turn in sockets when attempting
to tighten nut. Check condition of ball stud seals; replace
if necessary.
2. Install the relay rod to the idler arm and pitman arm
ball studs, making certain the seals are in place. Use J-23193
or J-23194 to seat the tapers, as shown in Fig. 3B1-6. A
torque of 20 N-m is required. With the tapers seated,
remove the tool. Install and tighten a torque prevailing to
54 N-m (40 ft. lbs.).
3. Install the tie rods to the relay rod as previously
described under "Tie Rod- Installation". Lubricate the tie
rod ends.
Fig. 3B 1-10-Checking Idler Movement, Typical
4. Lower the vehicle to the floor.
5. Adjust toe-in (see Section 3A) and align steering
wheel as described previously in Section 3B4 under
"Steering Wheel Alignment and High Point Centering".
IDLER A RM
Use of the proper diagnosis and checking procedure is
essential to prevent needless replacement of good idler arms.
1. Raise the vehicle in such a manner as to allow the
front wheels to rotate freely and the steering mechanism
freedom to turn. Position the wheels in a straight ahead
position.
2. Using a push pull type spring scale located as near
the relay rod end of the idler arm as possible, exert a 25 lb.
force upward and then downward while noticing the total
distance the end of the arm moves. This distance should not
exceed + 1 /8 inch for a total acceptable movement of 1/4
inch (Figure 3B1-10). It is necessary to ensure that the
correct load is applied to the arm since it will move more
when higher loads are applied. It is also necessary that a
scale or ruler be rested against the frame and used to
determine the amount of movement since observers tend to
over-estimate the actual movement when a scale is not used.
The idler arm should always be replaced if it fails this test.
Jerking the right front wheel and tire assembly back
and forth this causing an up and down movement in the
idler arm is not an acceptable method of checking since
there is no control on the amount of force being applied.
Caution should be used in assuming shimmey
complaints are caused by loose idler arms. Before suspecting
suspension or steering components, technicians should
eliminate shimmy excitation factors, such as dynamic
imbalance, run-out or force variation of wheel and tire
assemblies and road surface irregularities.
LIG H T T R U C K S ER V IC E M AN UAL