GMC C Series 1993, Repair Manual

Page: 90 / 264

REAR AXLE CONTROLS 4B2-3
D. Turn the gear so the pin is 90 degrees from the
centerline of the sliding block shaft.
5. Slider block (14). Make sure the slot in the block
engages with the gear pin.
6. Base housing (15).
A. Apply RTV sealer (GM P/N 1052366 or equiva­
lent) to outer edge of housing.
B. Align the dowel of the housing (15) with the
dowel hole in the motor housing (6) and press
the housings together.
7. Four screws (16).
V
Important
A. Loosely install the four screws (16).
B. Check to see if the housings are matching
properly by wiggling the slider block from side
to side.
Tighten
• Screws to 12 N-m (105 in. lbs.).
8. Motor (9).
• Apply RTV sealer (GM P/N 1052366 or equiva­
lent) on the motor housing (6) to circle the
motor gear and wire lead holes.
9. Three screws (10).
Tighten
• Screws to 6 N-m (50 in. lbs.).
10. Washer (5).
11. Circuit board (3).
A. Connect the black motor lead to the male termi­
nal in the center of the circuit board.
B. Install the circuit board on the gear shaft.
12. Nut (4).
Tighten
• Nut to 1.7 N-m (15 in. lbs.).
Figure 4—Circuit Board Wire Connections
13. Cover (1).
• Connect the three circuit board wires as follows:
A. Black Wire (18)— to the terminal nearest the
edge of the cover.
B. Green Wire (20)— to the center terminal.
C. Red Wire (19)— to the remaining terminal.
• Apply RTV sealer to outer edge of housing and
around the tapped holes for the cover screws.
14. Align the cover holes and press the cover in place.
15. Four screws (2).
Q Tighten
• Screws to 6 N-m (50 in. lbs.).
GENERAL DESCRIPTION
TWO-SPEED AXLE AIR
SHIFT UNIT
The air shift motor consists of a piston and rod
assembly that works against a preloaded spring. When
air pressure is applied, the piston compresses the
spring and shifts the axle to “LOW” range. When the air
pressure is released, the spring extends and shifts the
axle to "HIGH” range.