Chevrolet 1977 Monte Carlo, Repair Manual

Page: 77 / 428

REAR AXLE DIFFERENTIAL 4B-7
Fig. 8B--M easuring Gage Plate T hickness
thousandths on the rear face o f the pinion, this indicates that
the pinion during testing was found to have best tooth
con tact at a position varying from design or nom inal depth.
In order to com pensate for all o f the allow able
m achining variables, a procedure o f gaging the carrier and
shim m ing the pinion has been developed. A fter gaging a
carrier, the assembler m ust install the appropriate shim
between the drive pinion shoulder and rear bearing so that
pinion depth can be adjusted to the required position for best
tooth contact in each axle assembly.
Proper pinion depth is determ ined with Pinion Setting
G age J -2 1777-01.
1. Clean the housing assem bly and all gage parts to
insure accurate m easurements.
2. Lubricate front and rear pinion bearings w hich will
be used in final assem bly and position them in their
respective races in the carrier.
3. U se cloverleaf gage plate J-21777-29 for 8-1/2" ring
gear or J -2 1777-36 for 8-7/8" ring gear m ounted on preload
stud J -2 1777-43 insert stud through rear bearing and pilot
J -2 1777-35, and through front bearing and pilot J-21777-42.
Install the hex nut until snug and rotate the bearings to
Fig. 10B ~C hecking Ring Gear Backlash
m ake sure they are properly seated. See figure 18B for
illustration o f proper positioning.
4. H old the preload stud stationary with a wrench on
the flats and tighten hex nut. Tighten until 20 in. lbs. o f
torque are required to rotate the bearings, as shown in figure
19B.
5. M ount the side beairng discs J -2 1777-45 on the ends
o f arbor J -2 1777-1, using the step o f the disc that
corresponds to the bore o f the carrier.
6. Place the arbor and plunger assem bly into the
carrier, being sure the side bearing discs are seated properly.
7. Install the bearing caps finger tight to hold the discs
from m ovem ent.
8. Position dial indicator J-8001 on the m ounting post
o f the arbor w ith the contact button resting on the top
surface o f the plunger.
9. Preload the dial indicator on e-half revolution, and
tighten in this position.
10. Select the button on the gage plate that corresponds
to the ring gear size and rotate the plate until the plunger
rests directly upon that button.
Fig. 9 B—In s ta llin g D iffe re n tia l Shim
Fig. 1 1B -C h e ckin g Ring Gear Runout
O V E RH A U L M A N U A L