GMC 4000 Series Service Manual page 126

B U M P E R
U -B O L T S P A C E R
U -B O L T
S P R IN G
A S S E M B L Y
C A S T E R S P A C E R
A X L E C E N T E R
FRONT
Figure 3 — Front Spring Center M ounting
(All 4 0 0 0 -P S 4 5 0 0 M odelsI
2. Continue to raise vehicle until spring eye
clears hanger.
3. Using J-21978-1 remover adapter J-21058
nut and screw and J-21830-4, -7 receiver and
bridge, remove bushing from spring eye (fig. 7).
Installation
1. Using installer adapter J-21978-2 andtools
called out in Step 3 of "Removal" procedure, in­
stall bushing (fig. 7) with offset of bushing at top
of spring eye as shown in figure 9.
2. Lower vehicle to position spring eye in
hanger.
3. Install spring eye bolt and nut. Tighten nut
to 320-420 foot-pounds torque, then lower vehicle.
Series PS-4500 (With Spring Off Vehicle)
If bushing is replaced with spring off vehicle,
use a p ress and adapters J-21978-2 to remove
and install bushing.
1
Front Spring Hanger 8 Spring U -B olt
2 Fram e 9 Shock A bsorber B racket
3 R ear Spring Hanger 10 Spring Pad
4 Rebound Bolt 11 C aster Spacer
5 Wear Cushion 12 Dowel
Rebound Pin
6 13 Axle
7
Spring 14 Eye Bushing
Figure 4 — Front Spring Installation
("E" and "S " M odels 4500-6500 Series)
G M C S E R V I C E M A N U A L
S H O C K A B S O R B E R
S H O C K
A B S O R B E R B R A C K E T
U -B O L T N U T S
T-4856-11
-4854
t
Figure 5 — Rem oving Rubber Type Eye Bushing
(All Series Except PS4500)
SPRING LEAF REPLACEMENT
1. Mark down one side of springs to assure
original position of leaves, then place spring a s­
sembly in a vise or arbor p ress near center bolt.
2. When bolted type is used, remove rebound
clip, nuts, bolts, and spacers.
3. File off peened end of center bolt, then re­
move nut and bolt.
4. Release vise or arbor press slowly to avoid
possible injury. Separate spring leaves and clean
thoroughly, using a wire brush if necessary.
5. Replace any broken rebound clips by cut­
ting old rivet, and riveting new clip to spring leaf.
6. Replace broken leaf and stack leaves in
correct order, applying a thin film of graphite
grease to each leaf. Align center bolt holes in
spring leaves with long drift, then compress spring
leaves in vise or arbor p ress.
7. Install center bolt and nut and tighten firm ­
ly. Peen end of bolt to prevent nut loosening.
8. Remove spring from vise or arbor p ress.
Align spring leaves by tapping with hammer. In­
stall rebound clip, spacers, bolts, and nuts; tighten
Figure 6 — Installing Rubber Type Eye Bushing
(All Series Except PS4500)
Sec. 3C
Page 119
FRONT SPRINGS
J-21058