GMC 1989 Light Duty Truck, Repair Manual, Page: 306 / 998

4C4-18 K TRUCK FRONT AXLE
5. Gear (9) with retaining ring (
8
) (K15-25 models).
Drive gear into place with a plastic hammer.
6
. Washer (
11
) and new snap ring (12) (K35 models).
Make sure the snap ring seats properly in the
groove.
OUTPUT SHAFT SHIM SELECTION
• Refer to figures 1 through 4.
• It is necessary to select the proper size output shaft
shim ( 20 ) if any of the following components were
replaced:
— Shaft (1).
— Tube (5).
— Output shaft (23).
— Carrier case (29).
— Ring and pinion gears (37).
— Differential case (35).
— Bearings (33).
— Carrier connector (9) (K15-25 models).
Preferred Method:
Tool Required:
J 34672 Depth Gage (or equivalent)
Refer to figures 37 and 38.
Push on the inner end of the shaft (1), and move the
shaft outboard as far as it will go. The shaft must be
in this position when measuring dimension “ A” .
Measure dim ension “ A” . Use J 34672 or equivalent
(figure 38).
• K15-25: Tube flange machined surface to inner
surface of connector (9).
• K35: Tube flange machined surface to inner
surface of axle shaft shoulder.
Measure dim ension “ B.”
• Carrier machined surface to outer surface of
output shaft (23).
Subtract dimension “ A” from dimension “ B.”
The correct shim size will be one size smaller than
the figure obtained in step 5. Examples:
1 .
2
.
3.
4.
• If the figure obtained in step 5 was 3.53 mm,
use a 3.30 mm shim.
• If the figure obtained in step 5 was 3.30 mm,
use a 2.70 mm shim (K15-25 models) or 2.80
mm shim (K35 models).
7. Shims are available in the following sizes:
• K15-25 models: 1.27 mm 1.78 mm, 2.29 mm,
2.70 mm, 3.30 mm, 3.81 mm.
• K35 models: 1.80 mm, 2.30 mm, 2.80 mm, 3.30
mm, 3.80 mm, 4.30 mm, 4.80 mm.
Alternate Method
Use ONLY if proper tools for calculating the shim size
are not available.
Install or C onnect (Figures 1 throu g h 4)
1. Original shim (20) to the shaft (1). Use grease to
hold it in place.
2. Assembled axle tube and shaft to the carrier. Use no
sealer at this time.
3. Bolts (
6
). Tighten to 40 N m (30 ft. lbs.).
I|J M easure (Figure 39)
Tool Required:
J 8001 Dial Indicator (or equivalent)
Shaft (1) end play.
1. Install a dial indicator (J 8001 or equivalent) on
the axle tube end. The plunger of the indicator
must be at a right angle to the axle flange
(figure 39).
2
. Move the shaft (1) back and forth and read the
end play. Correct end play is 0.03-0.51 mm
(
0
.
001
-
0
.
020
-inch).
3. If end play is incorrect, install a thicker or
thinner shim as needed to bring end play into
the specified range.
R em ove or D isconnect (Fig ures 1 through 4)
1. Bolts (
6
).
2. Axle tube assembly.
FINAL ASSEMBLY
JJ? Clean (Figures 1 throu g h 4)
S e a lin g s u rfa c e s of th e tu b e (5) and c a rrie r
a s s e m b ly . R e m o v e a ll o il a n d g re a s e . U se
carburetor cleaner or equivalent.
Install or C onnect (Figures 1 throu g h 4)
1 . Shim (20), as selected previously, to the output shaft
(23). Use grease to hold it in place.
2. Sleeve (22).
3. Spring (14).
4. Shift shaft (18), spring (17), shift fork (16), and clip (15)
assembly to the carrier case.
• Damper spring fits into shift fork indentation.
• Make sure clip is seated in groove of shift shaft.
• Apply a bead of sealer (GM part no. 1052942
[Loctite 518] or equivalent) to the tube (5) sealing
surface.
3. Assembled tube (5) to the carrier assembly.
4. Bolts (
6
).