GMC 1989 Light Duty Truck Repair Manual page 196

4B5-8 DANA REAR AXLES
Figure 20— Differential with the Master Bearings
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 21).
3. Force the differential assembly as far as possible in
the direction towards the indicator.
4. Preload the dial indicator one half of its travel. Place
the tip of the indicator on a flat surface on the
differential, just next to a ring gear bolt. Mark this
location with a piece of chalk.
5. Zero the dial indicator.
6. Force the differential assem bly 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 measurement 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 housing.
• Do not rem ove the m aster b ea rin gs from the
differential.
Figure 2 1 — D eterm in in g D ifferen tial Shim Pack
PINION DEPTH ADJUSTMENT
Tools Required:
D-120 Master Pinion Block (Miller)
D-116-1 Pinion Height Block (Miller)
D-116-2 Master Discs (Miller)
D-115-3 Arbor (Miller)
D-115 Scooter Gage (Miller)
1. Clean the carrier bores and all the tools. The pinion
bore must be free of nicks and dirt.
2. Install D-120 to the pinion bore (figure 22).
3. Place D-116-2 onto D-115-3.
4. Install the arbor and discs into the axle housing
(figure 23).
5. Install D-116-1 onto D-120 and against the arbor
(figure 24).
6. Place D-115 onto the height block (figure 25).
• Place the gage on the lower step of the height
block. Push the gage down on the height
block. While applying pressure, set the dial
indicator at zero.
7. Slide the gage over the arbor (figure 26).
Figure 2 3 — A rb or and Discs