Chevrolet 70 1969 Series, Shop Manual

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TRANSMISSION AND CLUTCH 7-109
speed shift fork (6) in 3rd-4th speed clutch collar (19),
Figure 10. Pass shift rod through shift fork and rear
case boss.
10. Locate shift fork in its proper position and secure to
rod with set screw (5). Tighten set screw securely in
notch and torque to 50 lbs. ft. Secure with lock wire.
11. Assem ble poppet ball (4), spring (3) and spring retain­
er (2) in lower hole on right side of transm ission case.
12. In a similar m anner, assem ble poppet ball, spring and
spring retainer in upper hole.
13. W ith 3rd-4th speed shift rod in 4th speed position, use
large screwdriver and try to move lst-2nd shift fork
out of neutral position. If interlock is in place, lst-
2nd shift rod will be locked in neutral position.
14. R eturn 3rd-4th speed shift rod to neutral position.
R otate drive gear and check shifting of both rods to
m ake sure the forks are free in clutch collars and
move readily and completely into each gear position.
15. Use light coat of gasket cem ent and assemble cover
gasket to transm ission case.
16. Assem ble transm ission case cover (1) to case and se­
cure with cap screws, lock washers and stud nuts.
17. If breather was removed, use light coat of gasket ce­
m ent on threads of breather and assem ble to cover.
GEARS A N D CASE DISASSEMBLY (Figure 2)
DRIVE GEAR
1. Rem ove transm ission cover, shift forks, and shift rods
from transm ission as outlined under shift controls di­
sassembly.
2. Lock auxiliary transm ission in two gears by engaging
3rd-4th speed shift collar (1) with 4th speed gear (2)
and lst-2nd speed shift collar (3) with 1st speed gear
(4).
3. Pull cotter pins and use 2 -1 /8 ” socket to remove
drive gear and m ainshaft com panion flange nuts.
4. Use puller J-7804 or equivalent and remove drive gear
and m ainshaft com panion flanges.
5. R em ove cap screws and lock washers from drive gear
bearing cap (5). Use two puller screws 3/8-16 N .C . at
least 2 -1 /2 ” long and remove drive gear bearing cap
with bearings (6 and 7) and drive gear (8) intact.
6. S upport bearing cap assem bly on flange and press
drive gear free of bearing cap, bearings and spacer.
7. M ove drive gear bearing spacer (9) aside and use drift
to tap outer roller bearing and oil seal (10) out front
of bearing cap. Rem ove bearing spacer.
8. R em ove snap ring (11) and press drive gear rear b ear­
ing from bearing cap.
9. R em ove old gasket and sealing com pounds and wash
all parts thoroughly.
MAINSHAFT
1. Use a suitable puller and remove drive gear pocket
bearing (12) from front of m ainshaft.
2. R em ove retaining cap screws with lock washers from
m ainshaft and countershaft rear bearing caps (13 &
14). Separate bearing caps from gaskets, shims and
case. Tie countershaft shims (15) together for reas­
sembly. C heck and remove speedom eter bushing if it
is to be replaced. R em ove bearing cap oil seal (16) if
it is to be replaced.
3. Remove speedom eter drive gear or spacer and rear
bearing w asher (17) from m ainshaft.
4. Use a soft h am m er and tap forw ard on rear of m ain­
shaft to start rear bearing (18) off m ainshaft.
5. Use two pry bars to slide m ainshaft and gear assem ­
bly tow ard rear of case as far as possible. Remove
m ainshaft rear bearing (18) with puller th a t clam ps on
the snap ring of rear bearing.
6. Rem ove lsi speed gear thrust washer (19) from m ain­
shaft.
7. Rem ove 3rd-4th speed clutch gear collar (1) from
clutch gear (20).
8. Rem ove m ainshaft and gear assembly by lifting front
of shaft upw ard and out through top of case.
9. Slide 1st speed gear (4) and lst-2nd speed clutch col­
lar (3) off rear of mainshaft.
10. Rem ove 1st speed gear sleeve (21) if sleeve did not
com e off with gear.
11. Rem ove 3rd-4th speed clutch gear snap ring (22).
12. Support under rear of 2nd speed gear (23) and press
m ainshaft free of 3rd-4th speed clutch gear (20), 4th
speed gear (2) and sleeve (24).
13. Remove lock pin (25) from inside 4th speed gear
sleeve.
14. W ash all parts, dry and exam ine thoroughly before
assembly.
COUNTERSHAFT
1. Use soft drift and ham m er to tap countershaft for­
ward; this will remove front bearing cup (26) from
case.
2. Use soft drift and ham m er to tap countershaft rear­
ward to remove rear bearing cup (27) from case.
3. Rem ove countershaft and gear assem bly by lifting
countershaft up and out top of case.
4. Use a suitable puller and rem ove countershaft front
(28) and rear (29) bearing cones.
5. Rem ove countershaft drive gear snap ring (30). S up­
port countershaft drive gear (31) with parallel bars as
close to hub as possible. Press countershaft free of
gear.
6. Rem ove 4th speed gear snap ring (32). S upport 4th
speed (overdrive) gear (33) an d press countershaft free
of gear.
7. S upport 2nd speed gear (34) and press countershaft
free of gear.
GEARS A N D CASE ASSEMBLY
COUNTERSHAFT (Figure 3)
NOTE: All countershaft gears should fit tight on
the countershaft. As a shrink (or interference)
fit of .0015" to .003" is built into new parts, it
presents a field assembly problem.
CHEVROLET SERIES 70-80 H EAVY DUTY TRUCK S H O P M A N U A L