Chevrolet CHEVY VAN G10 SERIES Service Manual page 246

CLUTCHES & TRANSM ISSIONS 7-8
12. Refill transm ission w ith lubricant recom m ended in L ubri­
cation, Section "0 " o f this m anual.
13. Check and if necessary, adjust clutch or transm ission
control linkage to achieve proper operation.
TRANSM ISSION A LIG N M E N T
In some instances where " excessive" gear whine or high gear
hop o u t, particularly at 50 MPH and up, are encountered; and
after all other probable causes have been checked, an align­
m ent check o f the transm ission and clutch housing may be
helpful.
A special to o l, on w hich a dial indicator is m ou nted , is
necessary to check the transm ission case rear bore alignm ent.
This tool may be made from a new or good used clutch gear
w hich has a good bearing surface on the crankshaft pilot end
and at the front main bearing location.
The splines on the clutch gear shaft and the teeth on the
clutch gear should be ground o ff so the shaft m ay be rotated
in a clutch disc hub w ith o u t interference w hen assembled in
the car. Weld a piece o f 1 /4 " rod in th e m ainshaft pilot bore
long enough to extend o u t the case rear bore. Assemble a good
bearing on the clutch gear shaft and secure it w ith the clutch
gear bearing snap ring. A ttach a suitable dial indicator to the
rod.
Procedure
1. Remove the transm ission from the vehicle and com ­
pletely disassemble, except for the reverse idler gear.
N O T E : In any case where the clutch gear p ilo t or
p ilot bearing is excessively loose or w orn, the pilot
bearing should be replaced before checking the
transmission case rear bore alignment by the dial
indicator method.
2. Carefully install the special tool w ith the dial indicator in
the transm ission case w ith the face o f the indicator to the
rear o f the case and w ith the tracing finger contacting the
I.D. o f the case rear bore. Secure in place w ith a clutch
gear bearing retainer.
3. Assemble the transm ission case to the clutch housing and
tighten the four transm ission m ounting bolts securely.
N O T E : Be sure to clean o ff any paint or other
foreign material on the mating faces of the clutch
housing and transmission as any foreign material on
these faces w ill change alignment; also, check care­
fu lly for dings or burrs on these mating surfaces and
remove carefully as necessary.
4. Dial indicate the transm ission case rear bore and record
the indicator readings in the 12, 3,
positions.
N O T E : 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
travel. Set the dial indicator at " 0 " at this location
and then record the 3, 6, 9 and 12 o'clock readings
in rotation.
6
and 9 o 'clock
its maximum outward
Fig. 9 —Removing Mainshaft Rear Oil Seal
5. Install tem porary slotted shims betw een the transm ission
case and the clutch housing in the quantities and at the
b olt locations as necessary to bring m isalignment at the
transm ission case rear bore to a m axim um o f .005"
indicator reading in either the vertical or horizontal
direction.
E XA M P LE : If the m axim um indicator reading is
at 12 o'clock position, put shims on the tw o bo ttom
bolts.
6
. A fter the position and q uan tity o f shims has been
determ ined and recorded the transm ission case may be
removed.
NO TE: The clutch
stamped, showing the position where shims are to be
installed and the thickness o f shims at each location.
7. Inspect the external clutching teeth o f the clutch gear
and second speed gear. Inspect the second and third
speed clutch internal clutching te eth . If the teeth are
w orn or tapered, even slightly, the gears should be
replaced. Reassemble the transm ission.
8
. Install the transm ission assembly to the clutch housing,
using the correct num ber o f shims at the proper locations
as previously determ ined. Shims are available by unit part
num ber w ith each unit consisting o f the following shims:
4 - .0 0 2 " shims Identificatio n— tw o corners cut off.
2 - .0 0 5 " shims Iden tification — one corner cu t off.
1—.010" shims Identification— all corners square.
NO TE: These special shims have a tab on one end
fo r ease o f installation. Do not slot the shims fo r the
permanent installation.
REAR OIL SEAL REPLACEMENT
1. Raise vehicle on hoist.
2. Drain lubricant from transm ission.
3. Disconnect propeller shaft from transm ission as described
in Section 4 o f this m anual.
4. Pry seal out of extension or remove seal using tools
J-5859 and J-2619 (fig. 9).
5. Coat outer diam eter o f new oil seal w ith sealing cem ent.
Install new oil seal using tool J-5154.
6
. Reinstall propeller shaft as described in Section 4 o f this
m anual.
7. Check and refill transm ission w ith lubricant specified in
Section O o f this m anual.
8
. Lower and remove vehicle from hoist.
housing should then be
C H E V Y V A N SH O P M A N U A L