Chevrolet 70 1969 Series, Shop Manual

Page: 864 / 913

TRANSMISSION AND CLUTCH 7-118
gasket cement. Align oil and bolt holes.
9. Enter drive gear (43) through m ain case bearing bore
and tap bearing cap (1) to within 1/8-inch of seating.
10. Start all retaining bolts (41) with lock washers and
pull bearing cap hom e.
11. Pull up larger bolts first. Tighten to 75-80 foot­
pounds torque. Tighten smaller bolts to 45-50 foot-pounds
torque.
12. Position m ainshaft (23) assem bly in case by lowering
output end of m ainshaft into rear bearing opening. Lower
front end into position.
NOTE: If front bearing cap (1) and drive gear
(43) have not been assembled to case, do so at
this time. See steps 8-11 and previous "NOTE."
13. Slide m ainshaft forw ard and enter m ainshaft pilot
bearing (8) in pocket of drive gear (43). S upport rear of
m ainshaft and tap pilot bearing home.
14. If clutch gear (21) was not added to m ainshaft in step
7 of m ainshaft assembly procedure, position gear on
m ainshaft at this time. N ote instruction under step 7.
15. Position underdrive sliding clutch collar (20) on un­
derdrive clutch gear (21) with shift fork collar forward.
Long hub tow ard rear.
16. Position m ainshaft rear bearing (25) on shaft with
snap ring (22) of bearing tow ard rear. S upport m ainshaft
to align bearing with case bore and tap bearing into pro­
per position. Use bearing driver sleeve and ham m er or
press to install bearing.
17. Slide speedom eter drive gear over shaft and seat
against bearing.
18. Press new oil seal in m ainshaft rear bearing cap. D et­
erm ine that lower bushing for speedom eter driven gear
has been installed in cap. Speedom eter driven gear m ay
be used as installation tool for lower bushing. T ap bush­
ing hom e with soft ham m er.
19. Place speedom eter driven gear in cap and secure outer
sleeve. C heck rotation and end play of driven gear for
freedom.
20. Assem ble a new gasket to bearing cap using gasket
cement. Align oil passage holes in gasket and cap.
21. Slide rear bearing cap into position and secure with
cap screws and lock washers. Tighten cap screws to 75-80
foot-pounds torque.
22. Assem ble P.T.O . gaskets to case using gasket cement.
Position P.T .O . cover on openings and secure with cap
screws and lock washers. T ighten cap screws to 30-35
foot-pounds torque. O m it two cap screws which hold
parking brake cable bracket to case.
23. Install drain plug (33) and tighten securely.
24. Shift auxiliary sliding clutch collars (10 and 20) into
neutral position.
25. Shift cover rods (6 and 14) and forks (11) into neutral
position.
26. Position cover gasket (19) on case using gasket ce­
ment. Align holes in gasket and case.
27. Set cover (15) down on case (shift rods (6 and 14)
pointing forward), using care to enter shift forks (11) in
shift collar grooves.
28. Secure shift cover (15) to case with bolts (18) and
lock washers. Tighten 1/2-13 bolts to 75-80 foot-pounds
and 3/8-16 bolts to 30-35 foot-pounds torque. O m it two
cap screws which hold parking brake cable bracket to
case.
29. Fasten parking brake cable bracket to case with four
cap screws, tightening to torque specifications given in
steps 22 and 28 above.
30. Apply light coat of grease to O .D . of front bearing
cap (1) and slide hanger over bearing cap. H anger should
be free on cap.
31. S tart front and rear universal joint com panion flanges
on shafts.
IMPORTANT: Tight flanges should not be ham­
mered or pressed on input and output shafts.
Serious damage to flanges as well as internal
bearings will result from this practice. Use a
screw thread type puller that pulls flange on
shafts. This type puller is very effective when
used with impact wrench.
32. W hen flanges have been seated, tighten lock nuts (24
and 44) with im pact wrench and 2 -1 /8 ” socket. Tighten
nuts to 400-450 foot-pounds torque.
SPECIFICATIONS
GENERAL DATA
T ype...................................................Constant Mesh Helical Gear
Speeds........................................................................................ Three
Model N um ber........................................................................ 7231A
GEAR RATIOS
D irect...................................................
Overdrive............................................
Underdrive........................................
SHIMS
Countershaft Rear Bearing
Cap Shim Thickness....................
CLEARANCE BETWEEN
Shifting Forks and Shift Collars ..
COUNTERSHAFT AND GEARS
Drive Gear Bore I.D ........................
Countershaft Dia...............................
1.00
74
2.14
0.003”, 0.010”, 0.030’'
0.005”-0.016”
2.3725”-2.3715’
. 2.3740”-2.3735’
F it............................................................................. 0.0010”-0.0025”
Overdrive Gear Bore I.D........................................2.5005”-2.4995”
Countershaft Dia..................................................... 2.5020”-2.5015”
F it...............................................................................0.0010”-0.0025”
SHIFT ROD POPPET SPRING
Free Length (approx.)......................................................... 1 53/64”
Lbs. Pressure at 1 1 /4 ” ......................................................... 36-40
Solid Height (m ax.).............................................................. I 1/16”
GEAR BACKLASH
Main Drive Gear to Countershaft Drive Gear . . . 0.006”-0.011”
Mainshaft Overdrive Gear to Countershaft
Overdrive G ear....................................................... 0.006”-0.011”
Mainshaft Underdrive Gear to Countershaft
Underdrive G ear.....................................................0.006”-0.011’
Sliding Clutches to Clutch G ears.......................... 0.004”-0.007”
CHEVROLET SERIES 70-80 HEAVY DUTY TRUCK S H O P M A N U A L