TRANSMISSION AN D CLUTCH 7-39
NOTE: End play on 4th speed gear (11) must
be a minimum of .006 inches. The 4th speed
gear retaining washers are available in various
thicknesses.
10. Remove assembly from vise and install 4th and 5th
speed synchronizer assembly (8) on mainshaft (43)
with large end of hub toward the rear.
11. Install 1st and reverse gear (42) on mainshaft (43)
with fork slot toward front.
SHIFT BAR HOUSING ASSEMBLY
Refer to Figure 8P.
1. Position shift bar housing (2) on bench upside-down
with Welch plug openings toward repairman.
2. Install 1st and reverse rocker arm (8) on pivot pin
(3). then insert pin through housing from inside. Se
cure pin with washer and nut.
3. Assemble 1st and reverse shift rod (24), shift lug (19),
and rocker lug (18) in housing as'follows:
a. Install plunger spring (17) and plunger (16) in
1st and reverse shift lug (19) and secure with
adjusting nut (20). Adjust plunger so rounded end
is flush or slightly below flat ends of lug. Secure
adjustment with cotter pin (fig. 8P).
b. Starting at left side of shift bar housing (2),
push 1st and reverse shift rod (20) through
opening in housing and through front support
boss and while holding 1st and reverse rocker
lug (18) in position, continue pushing shift rod
through rocker lug.
c. Position lugs (18 and 19) on rod (24) so lock
screw holes in lugs align with screw holes in rod,
then install lock screws (13) in lugs, tighten
screws firmly, and secure with new lock wire.
d. Move 1st and reverse shift rod (24) into “ N eu
tral” position.
4. Install 4th and 5th shift rod (23) and 4th and 5th shift
fork (14) in housing (2) as follow's:
a. Install two interlock balls (7) in crossbore in rear
support boss between 1st and reverse and 4th
and 5th shift rod holes.
b. Place poppet spring (6), inner poppet spring, and
poppet ball (7) in well in center opening in rear
support boss.
c. Insert shift rod installer tool (J-8633) tapered end
first through forward side of center opening in
rear support boss. Push tool part way through
support boss to compress poppet spring.
d. Start 4th and 5th shift rod (23) in housing (2)
with interlock pin hole toward rear. Push rod
through front support boss, place 4th and 5th
shift fork (14) on shift rod with hub toward
rear, and install interlock cross pin (26) in hole
in shift rod.
e. Push 4th and 5th shift rod (23) through rear
support boss, driving installer tool out.
f. Align lock screw hole in shift fork with hole in
shift rod, then install lock screw (13), tighten
screw firmly, and secure with new lock wire,
g. Move shift rod into “ N eutral” position.
5. Install 2nd and 3rd shift rod (22) shift fork (11), and
shift lug (15) in housing (2) as follows:
a. Install two interlock balls (7) in crossbore in rear
support boss between 4th and 5th shift rod hole
and 2nd and 3rd shift rod hole.
b. Place poppet spring (6) and ball (7) in well in
rear support boss at 2nd and 3rd shift rod open
ing.
c. Insert shift rod installer tool (J-8633) tapered end
first through forward side of 2nd and 3rd shift
rod hole in rear support boss. Push tool part
way through support boss to compress poppet
spring.
d. Install 2nd and 3rd shift rod (22) in housing (2)
and push through front support boss.
e. Place 2nd and 3rd shift lug (15) and 2nd and
3rd shift fork (11) on shift rod, with hub of
both parts toward front.
f. Push 2nd and 3rd shift rod (22) through rear
support boss, driving installer tool out.
g. Align lock screw holes in shift lug and shift fork
with holes in shift rod, then install lock screws
(13), tighten screws firmly and secure with new
lock wire.
h. Move 2nd and 3rd shift rod (22) into “ N eutral”
position.
6. Install three welch plugs (25) in openings in front end
of housing (2).
7. Assemble 1st and reverse shift fork bar (4) and shift
fork
(9)
as follows:
a. Install yellow poppet spring (10) and ball (7)
in well in 1st and reverse shift fork
(9).
b. Insert installer Tool (J-8633) tapered end first
through shift fork from rear side to compress
poppet spring (10).
c. Insert 1st and reverse shift bar (4) through open
ing at rear of housing (2).
d. Position shift fork
(9)
and installer tool in housing,
then push shift bar (4) through shift fork, driving
out installer tool.
e. M ake sure shift fork engages 1st and reverse
rocker arm (8) when poppet ball is engaging
groove in shaft bar, then push shift bar forward
into rear support boss.
f. Align screw hole in bar with lock screw hole in
support boss, then install lock screw (5), tighten
screw firmly and secure with new lock wire.
8. Check assembly of shift bar housing by shifting in
and out of all speeds.
9.
Check action of interlock balls (7) and pin (26) by at
tempting to move two shift rods out of “ N eutral” at
the same time. Rods should not shift into more than
one speed at a time.
CONTROL TOWER ASSEMBLY
Key numbers in text refer to Figure 7P.
CHEVROLET SERIES 70-80 H EAVY DUTY TRUCK S H O P M A N U A L
Summary of Contents for 70 1969 Series
Page 1: ...CHEVROLET HEAVY DUTY TRUCK SHOP MANUAL...
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Page 11: ...LUBRICATION 0 4 CHEVROLET SERIES 70 80 HEAVY DUTY TRUCK SHOP MANUAL...
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