Chevrolet 1988 Light Duty Truck Repair Manual page 148

4B1-8 7 1 /2 AND 7
4 .3 2 M M (0.170-IN C H ) SERVICE SPACER
Total Thickness of
Both Prod. Shims
Rem oved
10.57 mm (0.420-inch)
10.92 mm (0 430-inch)
11.18 mm (0.440-inch)
11.43 mm (0.450-inch)
11 68 mm (0 460-inch)
11.94 mm (0.470-inch)
12.19 mm (0.480-inch)
12.45 mm (0.490-inch)
12.70 mm (0.500-inch)
12.95 mm (0.510-inch)
13.21 mm (0.520-inch)
13.46 mm (0.530-inch)
13.97 mm (0.550-inch)
Figure 13— Shim Thickness Chart
Install the shim(s) between the right bearing cup
5.
and the service shim.
The left bearing race and spacer must be against
the left side of the housing.
D e te rm in e b e a rin g
6
.
progressively larger feeler gage sizes between the
right service spacer and shim.
• Push the feeler gage downward so that it
contacts the shim at the top and bottom, and
then contacts the axle housing.
• Rotate the case while using the feeler gage.
This will assure an accurate reading.
• The weight of the case will cause a light drag.
Do not m istake this drag for bearing preload.
• Start with a thin feeler gage to obtain a feel for
when preload begins. It will be necessary to
work the case in or out and to the left in order
to insert the feeler gage.
• The point just before additional drag begins is
the correct feeler gage thickness. This is the
zero setting w ithout pre-load.
Remove the left bearing cap and shim(s) from the
a x le h o u s in g . M e a s u re th e
micrometer. The shim pack needed is the total of the
shim(s) and the feeler gage. An additional pre-load
of 0.10 mm (0.004-inch) will be added to each side of
the differential case after the backlash adjustm ent is
made.
Differential case, bearing cups, shims and spacers.
Install the pinion. Refer to " Pinion Installation" in
this section.
PINION INSTALLATION
Install or C o n n e c t
Tools Required:
J 5590 Rear Pinion Bearing Cone Installer
J 23911 Pinion Oil Seal Installer
J 8614-01 Pinion Flange Remover
• The bearing cups should have been installed in
" Pinion Depth A djustm ent," in this section.
1. The pinion inner bearing (18) using J 5590 (figure
14).
/ -INCH RING GEAR AXLES
s s
Total Thickness of
S ervice Shims To Be
Used As A Starting Point
1.52 mm (0.060-inch)
1.78 mm (0.070-inch)
2.03 mm (0.080-inch)
2.29 mm (0.090-inch)
2.54 mm (0.100-inch)
2 79 mm (0.110-inch)
3.05 mm (0.120-inch)
3.30 mm (0.130-inch)
3.56 mm (0.140-inch)
3.81 mm (0.150-inch)
4 06 mm (0.160-inch)
4.32 mm (0.170-inch)
4.83 mm (0.190-inch)
F-04685
p re -lo a d by in s e r tin g
s h im s u s in g a
Figure 14— Pinion Inner Bearing Installation
• Drive the bearing until the bearing cone seats
on the pinion shims.
A new collapsible spacer (17).
Lubricate the pinion bearings with axle lubricant.
Pinion (20) to the axle housing.
Outer pinion bearing (15) onto the pinion using
J 5590.
• Hold the pinion forward from inside the case
w hile driving the bearing onto the pinion.
Pinion oil seal (14) using J 23911.
The pinion flange (13) to the pinion by tapping it with
a rawhide ham m er until a few threads show through
the pinion flange.
The pinion washer (12) and a new nut (11) while
holding the pinion flange with J 8614-01.
T ig h ten
The nut until the pinion end play is just taken
up. Rotate the pinion while tightening the nut
to seat the bearings. Once there is no end play
in the pinion, the preload torque should be
checked.
R em ove J 8614-01. U sin g an in c h -p o u n d
torque wrench, check the pinion preload by
rotating the pinion with the wrench (figure 15).