GMC T Series 1994 Repair Manual page 821

TRANSM ISSIO N DISASSEMBLY
4"+
Remove or Disconnect (Figures 1 and 2)
Required:
iG G is
J 22912-01 Bearing and Gear Puller
J 37359 Countershaft Bearing Remover
• Remove drain bolt and drain the lubricant.
N O T IC E : R e m o v a l o f o f f s e t l e v e r in p o s it io n
o t h e r th a n n e u t r a l ( c e n t e r e d ) m a y r e s u l t in
d r iv in g th e r o ll p in in t o th e d e t e n t p la t e w ith ­
o u t r e le a s in g th e le v e r , m a k in g f u r t h e r d is a s ­
s e m b l y e x t r e m e ly d i f f i c u l t
• Position offset lever in neutral gate (centered).
1. Control lever (81).
• Boot and the dust cover.
2. Pin (84) from the offset lever (85) (figure 3).
3. Extension housing (90) to transmission case bolts
(93).
4. Extension housing (90) and the offset lever (85).
Important
• The offset lever is engaged into the extension
housing and cannot be removed when the
extension housing is mounted to the transmis­
sion.
5. Detent ball (87) and the spring (86) from the offset
lever (figure 4).
6. Pin from extension housing or the offset lever.
7. Oiling funnel (65) from rear of countershaft (52)
(figure 5).
8. Bolts (3) attaching transmission cover (1) and shift
fork assembly to the case (67).
Important
• Two of the cover mounting bolts are alignment
b o lts . N ote th e p o s itio n s th a t th e y w ere
removed from for reassembly.
9. Cover (1) from the case (67).
10. Reverse lever spring clip (76), pivot bolt (78), and
shift lever (77) (figure 6).
11. Backup lamp switch (79).
12. Fifth gear synchronizer snap ring (64) and retainer
(63) from the rear of the countershaft (52) (figure
7).
13. Reverse lock spring (68) from front of transmission
case by unhooking it (figure 8).
14. Fifth gear (57), synchronizer (62), shift fork (73),
and shift rail (75) as an assembly.
• If necessary, rotate rail to disengage it from
reverse lever assembly.
15. Speedometer gear (27) and retaining clip (28).
16. Snap ring (26) from the mainshaft (14) (figure 9).
• Mark the front bearing retainer and the case for
alignment.
17. Front bearing retainer bolts (95).
UNIT DISASSEMBLY
20. Main drive gear (100).
18. Front bearing retainer (96).
19. Front bearing race (99) and the shim pack (98)
(figure 10).
• Turn the gear so the cutout is toward the coun­
tershaft (figure 11).
•B e careful not to drop the 15 roller bearings,
thrust bearing, or race from the rear of the drive
gear.
21. Fourth gear blocker ring (31) from third/fourth syn­
chronizer.
22. Mainshaft rear bearing race (24).
• If the race sticks, it is probably misaligned in
the case bore. To free the race, work the shaft
back and forth.
23. Mainshaft (14) (figure 12).
• Tilt mainshaft upward and remove assembly
from the transmission case.
24. Reverse fork assembly from the transmission case.
25. Countershaft retainer (55) and shims (54) (figure
13).
26. Roll pin (71) from the forward end of the reverse
idler shaft (72) (figure 14).
27. Reverse idler shaft (72), rubber O-ring (69), and
gear (70) from the transmission case (67).
28. Rear countershaft bearing race (53).
29. C ountershaft bearing (51) using J 8433 with
J 22912-01 and J 37359 (figure 15).
Important
• Note the direction the bearing faces.
30. Countershaft (52).
• Move the countershaft assembly rearward, tilt it
upward, and remove from case.
M AINSHAFT DISASSEMBLY
❖ Disassembie (Figures 1 and 2)
Tool Required:
J 22912-01 Bearing and Gear Puller
1. Thrust bearing (29) and the race (30) from the front
of the main shaft (14).
• Scribe a reference mark on the third-fourth syn­
chronizer hub and sleeve for reassembly.
2. Third-fourth synchronizer, third blocker ring (31),
sleeve (34), hub (32), and third gear (35) as an
assembly from the mainshaft using J 22912-01 and
a press (figure 16).
3. Needle bearing assembly (36) and spacer (37) (fig­
ure 17).
4. Second gear snap ring (38) and thrust washer (39).
5. Second gear (40), spacer (42), and needle bearing
(41).
6. Spiral snap ring (43).
7. Thrust washer (44).
8. Three-piece second gear blocker ring assembly
(figure 18).
• Scribe a reference mark on first-second syn­
chronizer hub and sleeve for reassembly.