Adjusting Final Drive Bearings
The final drive bearing preload must be adjusted whenever the transmission case, gear carrier housing, differential housing, or differential bearings are replaced.
To adjust:
| 1. | If the bearing race is not installed in the gear carrier housing, install the shim and then drive in the bearing race as shown in Fig. 8-9. |
| Fig. 8-9. | Final drive bearing race being driven in. |
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CAUTION-
Do not interchange the bearings and their races. They are matched sets.
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NOTE-
The bearing race shim in the gear carrier housing is always 1 mm thick.
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| 2. | Without using a shim, install the bearing race into the transmission case. |
| 3. | Install the differential in the gear carrier housing and, using a new gasket, assemble the housing and the case. Install and torque five of the transmission case bolts to 25 Nm (18 ft. lb.). |
| 4. | Install a dial indicator as shown in Fig. 8-10 and set the indicator to show a preload of 1 mm. |
| Fig. 8-10. | Dial indicator set up for testing final drive bearing preload. |
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| 5. | Move the final drive up and down and note the amount of movement indicated by the dial indicator. The shim size needed to give the correct bearing preload is equal to the amount of movement plus 0.40 mm. For example, if the final drive moves up and down 0.90 mm, the shim thickness needed for correct preload is 0.90 mm + 0.40 mm = 1.30 mm. It may be necessary to use two shims to get the correct shim thickness and preload. Table g lists the shims available to set the preload based on this calculation. |
NOTE-
Do not turn the differential when measuring its movement up and down. This will cause the bearings to settle and give an incorrect reading.
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Table g. Shims For Adjusting Final Drive Bearing Preload
NOTE-
Part numbers are for reference only. Always rely on an authorized Volkswagen parts department for the most accurate and up-to-date parts information.
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| 6. | Disassemble the transmission case and the gear carrier, then drive out the bearing race in the transmission case. Install the shim of the correct thickness, as determined in step 5, and reinstall the race. |
NOTE-
If two shims are being used, install the thicker one first into the transmission case.
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| 7. | As a final check of bearing preload, reassemble the transmission case and gear carrier as described above and check the final drive turning torque as shown in Fig. 8-11. Table h gives turning torque specifications. Torque that is too high indicates inadequate clearance. Torque that is too low indicates too much clearance. |
| Fig. 8-11. | Checking final drive bearing preload by checking turning torque Specifications are given in Table h. |
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Table h. Final Drive Bearing Turning Torque
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