Chevrolet 1991 Light Duty Truck Repair Manual page 183

6. Force the differential assembly in the opposite
direction as far as it will go. Repeat this step until
the same reading is obtained. Record the number
of thousandths that the dial indicator traveled, not
the reading on the dial. This will be the measure­
ment of the shim pack without the bearing preload
(which will be added later).
7. Remove the dial indicator from the axle.
8. Remove the differential case from the axle hous­
ing.
• Do not remove the master bearings from the differ­
ential.
DETERMINING TOTAL DIFFERENTIAL SHIMPACK
SIZE— HEAVY DUTY MODEL
1. Assemble the differential case (22) to the axle
housing. The pinion must not be installed.
' 2. Mount a dial indicator having a minimum travel of
0.200-inch with a magnetic base on the ring gear
bolt side of the housing (figure 62).
3. Install the outboard spacer between the master
bearing and the axle housing on the ring gear
side.
4. Force the differential assembly as far as possible
in the direction towards the indicator.
5. Preload the dial indicator one half of its travel.
Place the tip of the indicator on a flat surface of
the differential, just next to a ring gear bolt. Mark
this location with a piece of chalk.
6. Zero the dial indicator, while still forcing the differ­
ential towards the indicator.
7. Force the differential assembly in the opposite
direction as far as it will go. Repeat this step until
the same reading is obtained. Record the number
of thousandths that the dial indicator traveled, not
the reading on the dial. This reading plus the
spacer measurement will be the thickness of the
spacer and shims required.
8. Remove the dial indicator from the axle.
9. Remove the differential case from the axle hous­
ing.
10. Remove the spacer (43) from the housing.
• Do not remove the master bearings from the differ­
ential.
PINION DEPTH ADJUSTMENT
Tools Required:
D-120 Master Pinion Block (60 and 70U)
D-137 Master Pinion Block (70B and 70 H.D.)
D-116-1 Pinion Height Block
D-116-2 Master Discs
D-115-3 Arbor
D-115 Scooter Gage
1. Clean the carrier bores and all the tools. The pin­
ion bore must be free of nicks and dirt.
2. Install D-120 or D-137 to the pinion bore (figure
63).
3. Place D-116-2 onto D-115-3 (figure 64).
4. Install the arbor and discs into the axle housing.
5. Install D-116-1 onto D-120 and against the arbor
(figure 65).
6. Place D-115 onto the height block (figure 66).
• Place the gage on the upper step of the height
block. Push the gage down on the height
block. While applying pressure, set the dial
indicator at zero.
DANA REAR A XLES 4B5-21