Chevrolet 10 Series 1968, Service Manual

Page: 220 / 713

REAR SUSPENSION AND DRIVE LINE 4-51
F ig . 95—Piston A ir -S h ift Unit Cross Section
1. S e lf-L o c k in g N ut 8. Piston
2. Housing 9. “ O ” Ring
3. Push Rod 10. Felt Wipers
4. Compression Spring 11. Piston Stop Cushion
5. A ctu atin g Lever 12. Vent
6. Bushing 13. C le v is Pin
7. C over Locating Bosses 14. G asket
and C over Bolts
“ Hi” ratio. Exhaust of air pressure from the cylinder
permits the piston and spring to return the axle gearing
to " L o ” ratio.
Rem oval
1. Bleed air from shift unit cylinder and disconnect air
line at piston housing cover.
2. Remove two stud nuts retaining shifting unit and pull
unit from differential carrier.
3. Remove shift fork seal and spring.
Disassem bly
1. Remove bolts, lock washers, housing cover and
gasket from shift unit housing. Drain lubricant.
2. Position housing in vise as shown in Figure 96.
3. Remove nuts and bolts retaining piston housing cover
to unit. Remove piston housing cover and
“ O”
ring
seal, replace seal whenever cover is removed.
4 .
Install Tool J-8107, Figure 97, over piston bore and
clamp onto flange, install a 9/16" socket over self­
locking nut and tighten down on tool until tension is
Fig . 96—Piston Housing C o ver Removal or Installation
relieved on clevis pin. Remove clevis pin (fig. 97).
5. Unscrew Tool J-8107 until compression spring ten­
sion is relieved and remove Tool (fig. 98).
6. Push piston, push rod and compression spring
through top of cylinder (fig. 99).
7. Remove actuating lever from housing.
Inspection
1. Inspect shift fork seal for good condition and tight fit
Fig . 97—C le v is Pin Removal or Installation
CHEVROLET TRUCK SERVICE MANUAL