GMC 1976 ZEO 6083 Maintenance Manual page 490

7- 4 2 TRANSMISSION
REAR UNIT END PLAY CHECKING
PROCEDURE
Make rear unit end play check as follows:
1 . Rotate transmission in holding fixture base so
that forward end of transmission is up .
2. Install Speedometer Puller Bolt, J-21797, in
one of the differential mounting bolt holes on end of
transmission case .
3 . Mount Dial Indicator, J-8001, on Bolt J-
21797, and index indicator to register with flat sur-
face on end of output flange, Figure 43 .
4. Set dial indicator to zero .
5. Using two screwdrivers (180° apart) more out-
put flange in and out. Note resulting travel or end
play for selection of washer for use at time of trans
mission assembly . End play should be .007 inch-.019
inch .
(NOTE: Use of two screwdrivers avoids an an-
gled condition and insures greater accuracy).
The selective washer controlling this end play is
the steel washer with the three tabs, located between
thrust washer and rear face of transmission case .
Notches and/or numerals on the tabs serve to iden-
tify washer thickness.
If a different washer thickness is required to
bring end play within specifications, it can be se-
lected from the following chart. The tabs will show
identification notches, numerals or both .
6. Remove Dial Indicator, J-8001, and Bolt, J-
21797, from transmission and rotate transmission so
that rear end of transmission is up.
REMOVE REMAINING
COMPONENTS
1 . Remove center support bolt from transmission
case, Figure 44, using a 3/8 inch 12-point thin wall
deep socket .
Figure 43-Checking Rear Unit End Play
2 . Remove intermediate clutch backing plate to
case snap ring, Figure 45 .
3 . Remove intermediate clutch backing plate,
and three composition and three steel clutch plates .
4. Using a needle-nose pliers, or screwdriver,
remove center support to case snap ring, Figure 46 .
5. Install Gear Assembly Remove and Installer
Adapter, J-21795, on end of main shaft so that tangs
engauge groove in shaft. Using Slide Hammer Han
dle, such as J-6125, and Speedometer Puller Bolt,
J-21797, tighten bolt on tool to secure tool on shaft,
Figure 47 .
6. Remove complete gear unit assembly from
case, by lifting straight up .
CAUTION: Be careful not to drop or bump
assembly in transmission case during re-
moval.
Figure 44-Remove Center Support Bolt
Thickness
Identification Notch
and/or Numeral
.074-078 None 1
.082-086 On Side of 1 Tab 2
.090-094 On Side of 2 Tabs 3
.098-102
On End of 1 Tab 4
.106-110 On End of 2 Tabs 5
.114 - .118 On End of 3 Tabs 6