Chevrolet Light Duty Truck 1973, Service Manual

Page: 624 / 979

7 M - 3 4 CLUTCHES & M A N U A L T R A N S M IS S IO N S
indicator in the transmission case with the face of
the indicator to the rear of the case and with the
tracing finger contacting the I.D. of the case rear
bore. Secure in place with a clutch gear bearing
retainer.
3. Assemble the transmission case to the clutch
housing and tighten the four transmission mount­
ing bolts securely.
NOTE: Be sure to clean off any paint or
other foreign material on the mating faces of
the clutch housing and transmission as any
foreign material on these faces will change
alignment; also, check carefully for dings or
burrs on these mating surfaces and remove
carefully as necessary.
4. Dial indicate the transmission case rear bore and
record the indicator readings in the 12, 3, 6 and 9
o’clock positions.
NOTE: It is best to start the reading at the 3,
6, 9 or 12 o’clock position closest to the point
where the indicator plunger reaches its
maximum outward travel. Set the dial
indicator at “O” at this location and then
record the 3, 6, 9 and 12 o’clock readings in
rotation.
5. Install temporary slotted shims between the
transmission case and the clutch housing in the
quantities and at the bolt locations as necessary to
bring misalignment at the transmission case rear
bore to a maximum of .005" indicator reading in
either the vertical or horizontal direction.
EXAMPLE: If the maximum indicator reading is at
the 12 o’clock position, put shims on the two bottom
bolts.
6. After the position and quantity of shims has been
determined and recorded the transmission case may
be removed.
NOTE: The clutch housing should then be
stamped, showing the position where shims
are to be installed and the thickness of shims
at each location.
7. Inspect the external clutching teeth of the clutch
gear and second speed gear. Inspect the second and
third speed clutch internal clutching teeth. If the
teeth are worn or tapered, even slightly, the gears
should be replaced. Reassemble the transmission.
8. Install the transmission assembly to the clutch
housing, using the correct number of shims at the
proper locations as previously determined. Shims
are available by unti part number with each unit
consisting of the following shims:
4—.002" shims Identification—two corners cut off.
2—.005" shims Identification—one corner cut off.
1-.010" shims Identification—all corners square.
NOTE: These special shims have a tab on
one end for ease of installation. Do not slot
the shims for the permanent installation.
REAR OIL SEAL REPLACEMENT
1. Drain lubricant from transmission.
2. Disconnect propeller shaft from transmission as
described in “PROPELLER SHAFTS” (Section 4)
of this manual.
3. On 3-speed transmissions, perform the following
replacement procedures:
a. Remove slip joint yoke from rear of transmis­
sion mainshaft.
b. Pry seal out of extension housing or remove oil
seal using oil seal remover (J-5859) and slide
hammer (J-2619) as shown in Figure 27.
c. Coat outer diameter of new oil seal with sealing
cement. Install new oil seal using extension
housing oil seal installer (J-5154).
d. Install slip joint yoke on rear of transmission
mainshaft.
4. On Muncie 4-speed transmissions, perform the
following:
a. Remove parking brake from rear of transmission as
described in “PARKING BRAKE” (Section 5),
when used.
b. Disconnect speedometer cable and remove speedom­
eter driven gear from mainshaft rear bearing cap.
c. Using flange or yoke holding tool, remove the out­
put yoke or companion flange nut. Pull output yoke
or companion flange nut off the mainshaft.
d. Remove mainshaft rear bearing cap and gasket. Dis­
card gasket.
e. Remove oil seal from rear bearing cap. Discard oil
seal.
f. Coat outer diameter of new oil seal with sealing
cement. Install oil seal in rear bearing cup using
a suitable installer. Drive seal flush with outside
of rear bearing cap, being careful not to damage
seal as shown in Figure 13.
NOTE: On Muncie 4-speed use Installer
J-22834 with Adapter J-22834-1 as required.
g. Clean all gasket surfaces, then install the rear
bearing cap with a new gasket on the
transmission. Tighten cap screws firmly.
h. Install output yoke or companion flange or
mainshaft. Using a flange or yoke holding tool
install retaining nut. Torque the retaining nut to
specification.
LIGHT DUTY TRUCK SERVICE MANUAL