Buick LeSabre 1965 Service Manual page 380

6-14
REAR AXLE
around ring gear. Lash must not
vary over .001" around ring gear.
If variation is over .001" check
for b u r r s , uneven bolting con-
ditions or distorted case flange,
and make c o r r e c t i o n s as
necessary.
3. Gear lash at the point of min-
imum lash should be .007" to
.009" for all new gears. If ad-
justment is necessary, adjust to
.008".
If original gear set having a wear
pattern is being reinstalled, orig-
inal gear lash should be main-
tained within ± .001".
4. If gear backlash is not within
s p e c i f i c a t i o n s , correct by
increasing thickness of one dif-
ferential s h i m and decreasing
thickness of other shim the same
amount. In this way, correct dif-
ferential bearing preload will be
maintained.
Shift .002" in shim thickness for
each .001" change in backlash
desired. If backlash is .001" too
much, decrease thickness of right
shim .002" and increase thick-
ness of left shim .002". If back-
lash is .002" too little, increase
thickness of right shim .004" and
decrease thickness of left shim
.004".
5. When gear backlash is cor-
rectly adjusted, remove 4 safety
head bolts and install bearing
caps a c c o r d i n g to markings.
Torque bearing cap bolts to 40- 60
ft. lbs.
6. Install new gasket in housing
using heavy grease to retain it
in place. Install cover. Torque
cover bolts to 25-35 ft. lbs. Wait
20 minutes and retorque cover
bolts to specification.
g. Install Axle
Shaft Assemblies
1. Apply a coat of wheel bearing
grease in bearing recesses of
housing. Install new outer re-
tainer gaskets. Apply a thin coat-
ing of Permatex #2 or equivalent
to outer diameter of seal if re-
placed. To help prevent damage
to the lip of the wheel seal when
installing axle shaft and to ensure
lubricant on the seal lip during
the first few miles of operation,
the axle shaft should be lightly
lubricated with axle lubricant
from the sealing surface to ap-
proximately 6 inches inboard of
the shaft. Insert axle shaft as-
semblies carefully u n t i l shaft
splines engage in differential to
avoid damage to seals.
2. Drive axle shaft assemblies
into position.
3. Place gasket and retainer over
studs and install nuts. Torque
nuts to 60 ft. lbs.
4. Install brake
wheel bolts.
5. Install w h e e l s
wheel nuts.
drums over
and tighten
h. Install Pinion Oil Seal with
Differential Installed in Car
In case of pinion oil seal failure,
remove old oil seal and install
new one (with differential remain-
ing in car) as follows:
1. Mark propeller shaft and com-
panion flange to permit proper
alignment at reinstallation. Dis-
connect propeller shaft from
companion flange and support
shaft out of way. If U- joint bear-
ings are not held by a retainer
strap, use a piece of wire or tape
to retain b e a r i n g s in t h e i r
journals.
2. Remove w h e e l s and brake
drums. Install an inch pound
torque wrench on pinion nut, and
record torque required to rotate
pinion freely.
3. Mark position of companion
flange, pinion shaft threads, and
pinion nut so that they can be re-
installed in the same position.
4. Remove companion flange nut
and washer using Holder J-8614-
01 to hold flange.
5. Pry oil seal out of carrier.
6. Examine surface of companion
flange for nicks or damaged sur-
face. If damaged, replace flange.
7. Examine carrier bore and re-
move any burrs that might cause
leaks around O.D. of seal.
8. Install oil seal using Pinion
Oil Seal Installer J- 21128.
9. Apply seal lubricant to O.D.
of companion flange.
10. While holding companion
flange with Holder J-8614-01, in-
stall companion flange nut and
tighten to same p o s i t i o n as
marked in Step 3 above. Tighten
nut 1/8 turn beyond alignment
marks on pinion shaft threads in
order to p r e l o a d collapsible
spacer. Check preload using an
inch pound torque wrench;torque
reading should be equal to or five
inch pounds above that recorded
in Step 2 preceding.
11. Connect propeller shaft to
companion flange using alignment
marks. Torque the four (4) bolts
to 15-18 ft. lbs.
6-7 DESCRIPTION OF
POSITIVE TRACTION
DIFFERENTIAL
a. General Description
Buick Positive Traction Differ-
ential is optional equipment on
all Buicks. It is designed to per-
form all the desirable functions of
a conventional differential and at
the same time overcome its lim-
itations. With a conventional dif-
ferential, when one wheel is on a
slippery surface, its pulling power
is limited by the wheel with the
lowest traction. Unlike the con-
ventional differential, with the
Positive Traction d e v i c e , the
anti- spinning action is limited by
the wheel having the best traction,
thus limiting the possibility of
becoming stuck.