Chevrolet 10 1971 Series Chassis Service Manual page 286

CLUTCHES AND TRANSMISSIONS 7-10
Fig. 12— Removing Mainshaft Rear O il Seal
2. Carefully install the special tool with the dial indi­
cator 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
Secure in place with a clutch gear bearing retainer.
3. Assemble the transmission case to the clutch housing
and tighten the four transmission mounting bolts
securely.
Be sure to clean off any paint or other
NOTE:
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.
It is best to start the reading at the
NOTE:
3, 6, 9 or 12 o'clock position closest to the point
where the indicator plunger reaches its maxi­
mum outward travel. Set the dial indicator at
" 0" at this location and then record the 3, 6, 9
and 12 o'clock readings in rotation.
5. Install temporary slotted shims between the trans­
mission case and the clutch housing in the quantities
and at the bolt locations as necessary to bring mis­
alignment at the transmission case rear bore to a
maximum of .005" indicator reading in either the
vertical or horizontal direction.
If the maximum indicator reading
EXAMPLE:
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.
The clutch housing should then be
NOTE:
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 hous­
ing, using the correct number of shims at the proper
locations as previously determined. Shims are avail­
able by unit part number with each unit consisting
of the following shims:
4--.002" shims
2--.005" shims
1--.010" shims
These special shims have a tab on one
NOTE:
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
bore.
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 12.
c. Coat outer diameter of new oil seal with sealing
cement. Install new oil seal using extension hous­
ing oil seal installer (J-5154).
d. Install slip joint yoke on rear of transmission
mainshaft.
4. On Muncie and New Process 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 speed­
ometer 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.
Discard gasket.
e. Remove oil seal from rear bearing cap. Discard
oil seal.
J-22834-2
J-22834-1
NOTE PARKING
BRAKE MOUNTING
FLANGE
Fig. 13— Replacing Rear Retaining O il Seal
Identification--two corners cut off.
Identification--one corner cut off.
Identification--all corners square.
10-30 CHEVROLET TRUCK SERVICE MANUAL