Dana 80: General Procedures
Differential Case and Pinion Set Up
Special Tools:
Special Tool(s)
Differential Case End Play Check
1. Install the outboard spacers in the side from which they were removed.
2. NOTE: Remove all nicks, burrs, dirt, etc. , from the differential case hubs, to allow the bearings to rotate freely.
Place the special tool on the differential case hubs, and position the assembly into the differential housing.
3. NOTE: Use a dial indicator with a minimum travel capability of 5.08 mm (0.200 inch).
NOTE: The rear axle uses a combination of differential bearing shims and selective outboard spacers to control differential case end play. The old outboard spacers provide a good starting point when setting end play. However, if additional shimming is necessary, beyond what the hardened differential bearing shims can provide, select and install different thickness outboard spacers.
Mount the special tools as shown. Locate the tip of the Clutch Housing Gauge on a flat surface of one of the bolts.
4. NOTE: Repeat this step and the following step until the same reading appears on the indicator each time. Record the reading. This is the total differential bearing shim thickness necessary, less preload. The final calculation occurs later during assembly.
Force the differential case as far as possible toward the indicator. With force still applied, set the indicator at 0.
5. Force the differential case as far as it will go in the opposite direction. Record the total differential case end play reading.
6. After making sure the reading is correct, remove the special tools and the differential from the differential housing. Do not remove the Master Bearings from the differential case at this time.
Pinion Ring Gear Variation Number
NOTE: If so equipped, install a new pinion shaft oil slinger if bent or mutilated.
NOTE: The differential ring gear and pinion is only available in a matched set. Matching numbers etched on both the differential ring gear and pinion are for verification. If installing a new differential ring gear and pinion, verify these numbers match before proceeding with assembly. The end of the pinion with the etched figures is the "button" end.
NOTE: Use the gear contact pattern method to verify the final pinion position is valid.
1. Shim the pinion as follows:
^ Etched on the button end of each pinion is a zero (0), or a plus (+) or minus (-) with a number. This number indicates the best running position for each particular differential ring gear. Shimming behind the inner pinion bearing controls this dimension.
2. Measure between the centerline of the differential ring gear to the back face of the drive pinion. The distance must be 147.6 mm (5.812 inch).
3. If reusing the old differential ring gear and pinion, measure and record the old drive pinion position shim thickness and select a new shim of the same dimension.
^ To change the pinion adjustment, shims are available in the thickness of 0.69 - 1.68 mm (0.027 - 0.066 inch). Measure each shim separately with a micrometer.
4. If installing a new differential ring gear and pinion, notice the (+) or (-) etching on both the old and new pinion, and adjust the new shim thickness to compensate for the difference of these two figures. If so equipped, include the oil slinger thickness in the total measurement to correctly set pinion depth.
^ For example, a pinion etched with m+8 (+3) requires 0.08 mm (0.003 inch) less shimming than a pinion etched "0". This means to increase the mounting distance by the amount etched in the pinion, subtract 0.08 mm (0.003 inch) from the drive pinion position shim selected for installation. A pinion etched m-8 (3), requires 0.08 mm (0.003 inch) more shimming than a pinion etched "0". In this instance, add 0.08 mm (0.003 inch) to the drive pinion position shim selected for installation to decrease the pinion mounting distance by the amount etched in the pinion.
New Pinion Conversion Chart (Metric)
Ring Gear and Pinion Backlash
1. Install the outboard spacers in the side from which they were removed.
2. Place the differential assembly with the special tool in the differential housing.
3. Install the special tools. Locate the tip of the Clutch Housing Gauge on a flat surface of one of the bolts.
4. NOTE: Repeat this step and the following step until the same reading appears on the indicator each time. This is the differential bearing shim thickness necessary between the differential case and the differential bearing on the differential ring gear side of the differential case.
Force the differential case (differential ring gear) away from the drive pinion. With force still applied, set the indicator at 0.
5. Force the differential ring gear into mesh with the pinion, to obtain an indicator reading. Record the reading.
6. Remove the special tools and the differential case from the differential housing.
7. Remove the Dummy Bearings from the differential case.
8. Place one shim, of the necessary thickness as determined from the previous measurement, on the differential ring gear side of the differential case. If additional shimming is necessary, beyond what the hardened differential bearing shim can provide, select and install a different thickness outboard spacer.
9. Using the special tool, install the differential bearing on the differential ring gear side of the differential case.
10. Determine the correct shim thickness, and place the shim on differential case hub on the drive pinion side.
^ To determine the correct shim thickness, first subtract the reading of the previous measurement from the total differential case end play reading obtained under Differential Case End Play Check. Then, add 0.25 mm (0.010 inch) to this amount. This is the correct thickness shim to place on the hub. If additional shimming is necessary, beyond what the hardened differential bearing shim can provide, select and install a different thickness outboard spacer.
11. Using the special tools, install the differential bearing.
1 Place the special tool on the differential bearing to protect it during the installation of the opposite bearing.
2 Using the special tool, drive the differential bearing onto the hub.