Chevrolet 1977 10 Series, Repair Manual, Page: 403 / 468

MANUAL TRANSMISSION
7B-23
4-SPEED (SAGINAW) 7 6 M M TRANSMISSION
INDEX
Disassembly of T ransm ission........................................ ..7B-23
Disassembly of M ainshaft............................................... ..7B-23
Cleaning and Inspection....................................................7B-23
Transmission Case........................................................ ..7B-23
B earings.......................................................................... ..7B-23
Gears and B ushings..................................................... ..7B-23
R epairs................................................................................. ..7B-23
Clutch Keys and Springs R ep lacem en t.................. ..7B-23
Extension Oil Seal or B u sh in g ....................................7B-26
Clutch Bearing Retainer Oil Seal............................. ..7B-27
Assembly of M ainshaft.................................................... ..7B-27
Assembly of T ransm ission.............................................. ..7B-28
DISASSEMBLY OF TR A N SM ISSIO N (Fig. 7B-1J)
1. Remove side cover attaching bolts and remove side
cover assembly.
2. Remove clutch gear bearing retainer bolts, retainer
and gasket.
3. Remove clutch gear bearing to gear stem snap ring,
then remove clutch gear bearing by pulling outw ard on clutch
gear until a screwdriver or other suitable tool can be inserted
between bearing, large snap ring and case to complete
removal (Fig. 7B-2J). The clutch gear bearing is a slip fit on
the gear and into the case bore. This provides clearance for
removal of clutch gear and m ainshaft assembly.
4. Remove extension to case attaching bolts.
5. Remove clutch gear, m ainshaft and extension
assembly together through the rear case opening (Fig. 7B-3J).
6. Using snap ring pliers, expand the snap ring in the
extension which retains the m ainshaft rear bearing (Fig. 7B-
4J) and remove the extension.
7. Using J-22246 at the front of the countershaft, drive
the shaft and its w oodruff key out the rear of the case. Tool
J-22246 will now hold the roller bearings in position within
the counter gear bore. Remove the gear and bearings (Fig.
7B-5J).
8. Remove reverse idler gear stop ring. Use a long drift
or punch through the front bearing case bore and drive the
reverse idler shaft and woodruff key through the rear of the
case (Fig. 7B-6J).
DISASSEMBLY OF M A IN SH A FT
1. Using snap ring pliers, remove the 3rd and 4th speed
sliding clutch hub snap ring from m ainshaft and remove
clutch assembly, third gear blocker ring and third speed gear
from front of m ainshaft (Fig. 7B-7J).
2. Depress speedometer retaining clip and slide gear
from mainshaft.
3. Remove rear bearing snap ring from mainshaft groove
(Fig. 7B-8J).
4. Support first gear with press plates and press on rear
of m ainshaft to remove first gear, thrust washer, spring
washer and rear bearing from rear of m ainshaft (Fig. 7B-9J).
5. Remove the 1st and 2nd sliding clutch hub snap ring
from the m ainshaft and remove the clutch assembly, 2nd
speed blocker ring and 2nd speed gear from the rear of the
mainshaft (Fig. 7B-10J).
CLEANING AND INSPECTION
Transmission Case
1. Wash the transm ission thoroughly inside and outside
with cleaning solvent, then inspect the case for cracks.
2. Check the front and rear faces for burrs, and if
present, dress them off with a fine mill file.
Front and Rear Bearings
1. Wash the front and rear ball bearings thoroughly in
a cleaning solvent.
2. Blow out bearings with compressed air.
CAUTION: Do not allow the bearings to spin, turn
them slowly by hand. Spinning bearings may
damage the race and balls.
3. Make sure bearings are clean, then lubricate with light
engine oil and check them for roughness by slowly turning
the race by hand.
Bearing Rollers
All clutch gear and countergear bearing rollers should
be inspected closely and replaced if they show wear. Inspect
counter shaft and reverse idler shaft at the same time, replace
if necessary. Replace all worn washers.
Gears
1. Inspect all gears for excessive wear, chips, or cracks
and replace any that are worn or damaged.
2. Check both clutch sleeves to see that they slide freely
on their hubs.
Reverse Idler Gear Bushings
The bushing used in the idler gear is pressed into the gear
and finish bored in place. This insures the positive alignment
of the bushing and shaft as well as proper meshing of the
gears. Because of the high degree of accuracy to which these
parts are machined, the bushing is not serviced separately.
REPAIRS
Clutch Keys and Springs
NOTE:
The clutch hubs and sliding sleeves are a
selected assembly and should be kept together as
originally assembled, but the keys and two springs may
be replaced if worn or broken.
1. M ark hub and sleeve so they can be matched upon
reassembly.