Chevrolet 1977 10 Series, Repair Manual, Page: 389 / 468

MANUAL TRANSMISSION
7B-9
3 SPEED (TREMAC) 7 7 M M TRANSMISSION
INDEX
Overhaul O perations........................................................ ..7B-9
Transmission D isassem bly..............................................7B-9
Mainshaft D isassem bly................................................. ..7B-13
Cleaning and Inspection............................................... .7B-13
Transmission Case........................................................ .7B-13
Front and R ear Bearings............................................ .7B-13
Roller Bearings...............................................................7B-13
G ears................................................................................ .7B-13
R epairs.................................................................................7B-13
Synchronizer Keys and Spring....................................7B-13
Extension Oil Seal or B u sh in g ....................................7B-14
Clutch Bearing Retainer Oil Seal............................. ..7B-14
M ainshaft Assembly......................................................... ..7B-14
Transmission A ssem bly.....................................................7B-15
OVERHAUL OPERATIONS
TR A N SM IS S IO N DISASSEMBLY
1. Remove lower extension housing bolt and drain
transm ission (Fig. 7B-3B).
2. Remove top cover and gasket from case.
3. Remove long spring that retains the detent plug in the
case (Fig. 7B-4B). Remove the detent plug with a small
magnet.
4. Remove extension housing and gasket.
5. Press down on speedometer gear retainer and remove
speedometer drive gear and retainer from output shaft.
6. Remove fill plug from right side of case (Fig. 7B-3B).
W orking through the plug opening drive out countergear roll
pin with a 3/16 inch pin punch that has been chamfered
slightly.
NOTE:
D o not attem pt to retrieve pin at this time. Pin
can easily be retrieved after output shaft assembly is
removed.
7. Insert dum m y shaft tool J-25232 into bore at front of
case, tap lightly on tool to push countershaft out rear of case
(Fig. 7B-5B).
NOTE:
W ith countershaft removed, allow countergear
to lie at bottom of case.
8. Punch alignm ent m ark in front bearing retainer and
transmission case to ensure correct assembly and remove
front bearing retainer and gasket (Fig. 7B-6B).
9. Remove large locating snap ring from front bearing
and smaller snap ring from clutch gear shaft.
10. Remove clutch shaft front bearing using tool J-6654-
01 and tool J-8433-1 (Fig. 7B-7B).
NOTE:
It may be necessary to alternate the tightening
of the bolts between tools J-6654-01 and J-8433-1 to
remove the front bearing.
11. Remove large locating snap ring from rear bearing
and smaller retaining snap ring from output shaft.
NOTE:
It may be necessary to place a screwdriver or
a piece of bar stock between the case and the first-reverse
sleeve and gear assembly. This will hold the output shaft
assembly in place while removing the rear bearing.
12. Remove rear bearing from output shaft using tool
J-8 157-01 (Fig. 7B-8B).
Fig. 7B-1 B--3-Speed (Tremec) 77mm Transmission