A D Ju Stm En - Chevrolet 1980 Light Duty Truck Repair Manual

FRONT WHEEL DRIVE
4C-8
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
C O N C A V E SIDE
(C O A S T)
Fig. 4C-13--Gear Tooth Pattern C ontact Pattern
A d ju s tm e n ts A ffe c tin g Too th C o n ta c t
Tw o adjustments 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 adjustments should be within specifications
before proceeding w ith
adjustments.
It may 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
tolerences. Increasing shim thickness will m ove the pinion
closer to centerline o f the ring gear. Decreasing shim
thickness will m ove pinion farther away from centerline of
the ring gear.
Backlash is adjusted by m eans o f the side bearing
adjusting shim s which 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
backlash and drive pinion
for m anufacturing
O V E R H A U L M A N U A L