Exploded View-Typical Positive Traction Differential - Pontiac TRANS AM 1977 Service Manual

4B-4 1977 PONTIAC SERVICE MANUAL
Fig. 48-2 Exploded View
-
Typical Positive Traction
Differential
DIAGNOSIS
Condition Possible Cause
1. Noise is the same in "Drive"
1 .a. Road noise
or "Coast" b. Tire noise
c. Front wheel bearing noise
d. Front or rear U-joint angle too great
2. Noise changes on a different
type of road
3. Noise lowers tone as car
speed is lowered
4. Similar noise is produced
with car standing and
driving
5. Vibration
6. A knock or click
approximately every two
revolutions of rear
wheel
7. Noise most pronounced on
turns
2.a. Road noise
b. Tire noise
3. Tire noise
4.a. Engine noise
b. Transmission noise
c. Driveline angle
5.a. Rough rear wheel bearing
b. Unbalanced or damaged propeller shaft
c. Tire unbalance
d. Worn universal joint in propeller shaft
e. Front or rear U-joint angle too great
f. Mix-indexed propeller shaft at
pinion flange
g. Pinion flange runout too great
6. A brinelled rear wheel bearing
7. Differential side gear and pinion