Chevrolet 1977 Monte Carlo, Repair Manual

Page: 134 / 428

4C-8
FRONT W HEEL DRIVE
C O N C A V E SIDE
(C O A S T )
C O N V E X SIDE
(DRIVE)
F ig . 4 C - 1 2 - - G e a r T o o t h N o m e n c l a t u r e
A d ju s tm e n ts A ffe c tin g T o o th C o n ta c t
T w o adjustm ents can be m ade which will affect tooth
contact pattern. These are backlash and position o f drive
pinion in carrier. The effects o f bearing preloads are not
readily apparent on hand loaded teeth pattern tests:
however, these adjustm ents should be within specifications
before proceeding w ith backlash and drive pinion
adjustments.
It m ay be necessary to adjust both pinion depth and
backlash to obtain the correct pattern.
The position o f the drive pinion is adjusted by
increasing or decreasing the shim thickness between the
pinion head and inner race o f rear bearing. The shim is used
in the differential to com pensate for m anufacturing
tolerences. Increasing shim thickness will m ove the pinion
closer to centerline o f the ring gear. D ecreasing shim
thickness will m ove pinion farther away from centerline o f
the ring gear.
Backlash is adjusted by m eans o f the side bearing
adjusting shim s w hich m oves the entire case and ring gear
assembly closer to, or farther from the drive pinion. (The
adjusting shim s are also used to set side bearing preload).
To increase backlash, increase right shim and decrease left
Fig. 4C-13--Gear T ooth Pattern C ontact Pattern
O V E R H A U L M A N U A L