Ford COUGAR 1968 Shop Manual page 106

GROUP 4
-
Rear Axle
I. Pinion bearing noise can be
identified as a .constant grinding
noise. Pinion bearings are rotating at
a higher speed than differential side
bearings or axle shaft bearings. The
noise is most noticeable a t a slight
pull between 18 to 25 miles per hour.
2. Wheel bearing noise may be
confused with rear axle noise. To
differentiate between wheel bearings
and rear axle, drive, the vehicle on a
smooth road a t medium low speed.
With traffic permitting, turn the vehi-
cle sharply right and left. If noise is
caused by wheel bearings, the noise
will increase on the defective bear-
ing because of side loading.
3. Side bearings will produce a
constant grinding noise of a slower
nature than pinion bearing, (side
bearing noise cannot be determined
by the wheel bearing test), but will
be in the same frequency as axle
shaft bearings.
Also, certain trouble symptoms are
common to both the conventional
and limited slip differential axles,
while still other symptoms are found
only in the limited slip differential.
To determine whether the vehicle is
equipped with a conventional or a
limited slip differential, check the vehi-
cle warranty plate and the axle ratio
tag. Refer to VEHICLE IDENTIFI-
CATION a t the front of this manual.
LIMITED-SLIP DIFFERENTIAL
The limited-slip differential can be
checked for proper operation without
removing the carrier from the axle
housing.
Jack up one rear wheel and re-
move the wheel cover. On a vehicle with
a removable carrier type axle, install
tool T59L-4204-A on the axle shaft
flange studs as shown in Fig. I. On
a vehicle with an integral carrier type
axle, use tool T65K-4204-A.
Using a torque wrench of a t least
200 ft-lbs capacity, rotate the axle
shaft. Be sure that the transmission
is in neutral gear, one rear wheel is
on the floor, and the other rear wheel
is raised off the floor.
The torque re-
quired to continuously rotate the
shaft should be a t least 75 ft-lbs. (Re-
movable type carrier) and 50 ft-lbs (In-
tegral type carrier). The initial break-
away torque may be higher than the
continuous turning torque, but this is
normal. The axle shaft should turn
with even pressure throughout the
check without slipping or binding.
I f the torque reading is less than
the specified minimum, check the dif-
ferential for improper assembly.
A
vehicle equipped with a limited-
slip differential will always have both
wheels driving. I f , while the vehicle is
being serviced, only one wheel is raised
off the floor and the rear axle is driven
by the engine, the wheel on the floor
will drive the vehicle off the stand or
jack.
GEAR T O O T H C O N T A C T
PATTERN CHECK
When, rolling a tooth pattern, use
the special compound (tube) packed
with each service ring gear and pinion
set.
Paint all gear teeth and roll a pat-
tern as described in Section 3. After
diagnosing the tooth pattern as ex-
plained here, make the appropriate
adjustments as outlined in Section 2.
In making a final gear tooth con-
tact pattern check, it is necessary to
recognize the fact that there are three
different types of gear set, hunting,
non-hunting and partial non-hunting.
Each type is determined by the num-
ber of teeth in the gears. The non-hunt-
ing and partial non-hunting types can
be identified by the paint timing marks
on the pinion and ring gear teeth
(Part 4-2, Fig. 25). See Part 4-4 for
complete identification specifications.
ACCEPTABLE TOOTH
PATTERNS (ALL AXLES)
Figure . 2 shows acceptable tooth
patterns for all axles. Any combina-
tion of drive and coast patterns will
be acceptable.
In general, acceptable tooth pat-
erns should have the following char-
acteristics:
1. The drive pattern should be
fairly well centered on the tooth.
2. The coast pattern should be
fairly well centered on the tooth.
3. Some clearance between the
pattern and the top of the tooth is
desirable.
4. There should be no hard lines
where the pressure is high.
The individual gear set need not
conform exactly to the ideal pattern
in order to be acceptable. Any com-
bination of drive and coast patterns
shown in Fig.
2
are acceptable.
H U N T I N G GEAR S E T
In a hunting-type gear set, any one
pinion gear tooth comes into contact
with all ring gear teeth. In this type,
several revolutions of the ring gear
are required to make all possible gear
combina tions.
NON-HUNTING GEAR SET
In a non-hunting type gear set, any
one pinion gear tooth comes into con-
tact with only a few ring gear teeth.
In this type, only one revolution of
the ring gear is required to make all
possible tooth contact combinations.
Any combination of drive and coast
patterns shown in Fig.
2
are acceptable.
PARTIAL NON-HUNTING
GEAR SET
In a partial non-hunting type gear
set, any one pinion tooth comes into
contact with only part of the ring
gear teeth, but more than one revo-
lution of the ring gear is required to
make all possible gear tooth combi-
nations.
Any combination of drive
and coast patterns shown in Fig. 2
are acceptable.
S H I M CHANGES AND
BACKLASH
Since each gear set rolls a character-
istic pattern, the patterns shown in
Fig. 2 are considered acceptable and
should be used as a guide. The drive
pattern is rolled on the convex side of
the tooth, and the coast pattern is
rolled on the concave side.
The movement of tooth contact
patterns with changes in shimming
can be summarized as follows:
Integral Carrier Type Axle
1. Thinner shim with the backlash
set to specifications moves the pinion
farther from the ring gear.
2. Thicker shim with the backlash
set to specifications moves the pinion
closer to the ring gear.
If the patterns are not correct,
make the changes as indicated. The
differential case and drive pinion will
have to be removed from the carrier
casting to change a shim. When re-
installing the pinion and ring gear of
a non-hunting or partial non-hunting
gear set, be sure that the marked
tooth on the pinion indexes between
the marked teeth
on^
the ring gear
(Fig. 25, Part 4-2). Refer to Pinion
and Ring Gear Tooth Contact Adjust-
ment, Section 2.
Removable Carrier Type Axle
1. Thicker shim with the backlash
set to specifications moves the pinion
farther from the ring gear.
2. Thinner shim with the backlash
set to specifications moves the pinion
closer to the ring gear.