GMC 1982 Light Duty Truck Service Manual page 243

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, thus 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 shimmy com­
plaints 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.
Rem oval
1. Raise vehicle on a hoist.
2. Remove the nut from ball stud at the relay rod. Remove
the ball stud from the relay rod by tapping on the relay
rod boss with a hammer, while using a heavy hammer
as a backing (Fig. 3B1-7).
3. Remove the idler arm to frame bolt and remove the
idler arm assembly.
Installation
NOTICE:
See the NOTICE on page 1 of this section
regarding the fasteners referred to in steps
1. Position the idler arm on the frame and install the
mounting bolts (special plain washers under bolt
heads); torque the nuts to
2. Make sure that the threads on the ball stud and in the
ball stud nut are clean and smooth. If threads are not
clean and smooth, ball stud may turn in the socket
when attempting to tighten nut. Check condition of ball
stud seal; replace if necessary.
3. Install the idler arm ball stud in the relay rod, making
certain the seal is positioned properly. U se a %-18
free-spinning nut to seat the tapers, per Fig. 3B1-6.
4. Lower the vehicle to the floor.
IDLER ARM — P SERIES MOTORHOME
The frame mounted idler support assembly is adjusta­
ble for support shaft end play. Check for idler arm move­
ment at the relay rod end as indicated above. If the move­
ment at the end of the arm exceeds ± 1/16 inch (
total movement), readjust the support shaft end-play as
follows:
1. Loosen the support assembly jam nut.
2. Tighten the adjusting plug to metal-to-metal contact.
3. Back off the adjusting plug
the square nut, or 45°).
4. Retorque the jam nut to 25-35 ft. lbs., while taking care
that the adjusting plug does not rotate.
P IT M A N A R M
Rem oval
1. Raise vehicle on hoist.
2. Remove nut from pitman arm ball stud.
3. Remove pitman arm or relay rod from ball stud by
and 3.
1
ft. lbs.).
40N«m (30
inch
1/8
a turn 2 of a flat on
Vs o f (V
tapping on side of rod or arm (in which the stud
mounts) with a hammer while using a heavy hammer or
similar tool as a backing. Pull on linkage to remove
from stud.
4. Remove pitman arm nut from pitman shaft or clamp
bolt from pitman arm, and mark relation of arm
position to shaft.
5. Remove pitman arm, using Tool J-6632 or J-5504.
Installation
NOTICE:
See the NOTICE on page 1 of this section
regarding the fasteners referred to in steps 3 and 4.
1. Install pitman arm on pitman shaft, lining up the marks
made upon removal.
NOTICE:
If a clamp type pitman arm is used, spread the
pitman arm just enough, with a wedge, to slip arm onto
pitman shaft. Do not spread pitman arm more than
required to slip over pitman shaft with hand pressure.
Do not hammer or damage to steering gear may result.
Be sure to install the hardened steel washer before
installing the nut.
2. Make sure that threads on ball studs and in 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.
3. Install pitman shaft nut or pitman arm clamp bolt and
torque to specifications, (C, G, 2 6 0 N»m; K, 125 N*m;
P, 1 8 0 N .m ).
4. Position ball stud onto pitman arm or relay rod. Use a
%-18 free-spinning nut to seat the tapers, per Fig.
3B1-6.
5. Lubricate ball studs.
. Lower the vehicle to the floor.
6
STEERING C O N N E C T IN G ROD (K MODELS O N L Y )
Removal
1. Remove cotter pins from ball studs, and then remove
the castellated nuts.
2. Remove ball studs from steering arm and pitman arm
boss with a heavy hammer and striking other side of
boss with lighter hammer (similar to method shown in
(Fig. 3B1-7).
Installation
NOTICE: See the NOTICE on page 1 of this section
regarding the fasteners referred to in step 3.
1. Make sure that threads on ball studs and in ball stud
nuts are clean and smooth. If threads are not clean and
smooth, ball studs may turn in connecting rod when
attempting to tighten nut. Check condition of ball stud
seals-replace if necessary.
2. Install ball studs in steering arm and pitman arm. (Be
sure to install the long end of the connecting rod
assembly to the pitman arm, as shown in Fig. 3B1-5).
3. Install ball stud nuts and torque to
Never back off nut to align cotter pin, always tighten
nut to next slot that lines up with hole in stud.
4. Install cotter pins and lubricate ball studs. For proper
alignment and orientation of connecting rod clamps see
Figure 3B1-1 .
1
STEERING LINKAGE 3B1-9
ft.
95 N*m (70 lbs.)