Pinion and Ring Gear, Adjusting
Pinion and Ring Gear, Adjusting
=> [ Drive Trains, Adjusting and Labeling ]
=> [ Shim Position ]
=> [ Adjusting Overview ]
=> [ Drive Train Adjusting Sequence ]
=> [ Pinion, Adjusting ]
=> [ Ring Gear, Adjusting ]
• The pinon and the ring gear must be adjusted exactly for the service life and quiet running of the final drive. For this reason, the pinions and ring gears are paired during the manufacturing process and are checked for wear and noise. Moving the pinion by the axle adjusts the quiet running because the torsional backlash is moved within the specified tolerance.
• The difference r, in reference to the master gauge Ro, is written on the outer circumference of the ring gear.
• Replace the drive train (pinion and ring gear) together only.
Drive Trains, Adjusting and Labeling
1 "O937" means Oerlikon-drive train a 37 : 9 ratio
A Klingelnberg-drive train "K937" or a Gleasen-drive train "G937" may also be installed.
2 - 312 - Drive Train Pairing Number
3 Dimension "r" refers to the master gauge used by the test machine during production. Dimension "r" is always given in 1/100 mm. Example: "25" means r = 0,25 mm
Ro - Length of the master gauge in the test machine "Ro"
Ro - Ring gear = 57.50 mm
R - Actual dimension between the ring gear and the front side of the pinion at the point of the greatest running smoothness for this one drive train.
Vo - Hypoid gear
Shim Position
S1 - Shim for Ring Gear Inside the Final Drive Cover
S2 - Shim for the Ring Gear Inside the Rear Axle Housing
S3 - Shim for the Pinion Inside the Rear Axle Housing
Adjusting Overview
• When working on the rear final drive, it is necessary to adjust the pinion or the drive train only if parts were replaced, which directly influence the final drive adjustment. To prevent unnecessary adjustments, note the following table:
Drive Train Adjusting Sequence
If the pinion and the ring gear must be adjusted, then follow this sequence:
• Determine the total shim thickness S total (S1 plus S2) for the specified pre-load on the tapered roller bearing/differential.
• Determine the shim thickness S3 for the specified installed position of the pinion.
• Divide the total shim thickness S total (S1 plus S2) so that the specified torsional backlash between the ring gear and pinion is present.
The purpose of the adjustment is attach the position of the greatest running smoothness, which was set by the test machine during production. For the correct result, use care and make sure the work area is as clean as possible.
Pinion, Adjusting
The pinion must be adjusted only if the drive train, pinion tapered roller bearing or rear axle housing were replaced.
Special tools, testers and auxiliary items required
• Universal Measuring Tool (VW 385)
• Holding Fixture (VW 540)
• Torque Gauge (VAS 6222)
• Dial Gauge
• Long Socket (SW 36)
Determining Shim Thickness S3
• Determine the total shim thickness S total (S1 plus S2) for the specified pre-load on the tapered roller bearing/differential before adjusting the pinion.
(Adjusting the pre-load on the tapered roller bearing/pinion).
- Place the rear final drive in the assembly stand => [ Place the Rear Final Drive in
the Assembly Stand ] Service and Repair
- Install both tapered roller bearing outer races into the housing without shims => [ Installing the Outer Race/Large
Tapered Roller Bearing ] Service and Repair
• Install the new tapered roller bearing and do not oil it.
• Install the spacer sleeves only when the friction torque adjustment is completed (shim S3 is already selected).
- Install the pinion with the inner race/large tapered roller bearing into the housing without spacer sleeve.
- Warm the inner race/small tapered roller bearing to approximately 100 °C (212 °F) and then mount it on the pinion.
Wear protective gloves.
- Install the driveshaft flange and then tighten the nut => [ Pinion Nut, Tightening and Friction
Torque, Adjusting ] Service and Repair.
Slowly increase the torque and read the friction torque several times.
Use the (VAS 6222) and the (SW 36) to measure the friction torque.
Adjust the following friction torques:
* Driven at least 50 km
Determining Dimension "a"
- Adjust the ring on the measuring bar (VW 385/1) to dimension "a" = 60 mm.
- Adjust the moveable ring to dimension "b" = 55 mm.
- Assemble the (VW 385/1) as illustrated.
• Extension pin (VW 385/15) = 9 mm long.
• Adjust the adjustable master gauge (VW 385/30) to Ro = 57.50 mm.
• Set the dial gauge (3 mm measuring range) to zero with 2 mm preload.
- Turn the pinion 8 turns in both directions so that the tapered roller bearings settle in.
- Lay the magnetic plate 50 mm diameter on the pinion head.
- Remove the master gauge and install the measuring mandrel into the housing.
- Install the rear final drive cover and tighten the 4 bolts.
- Pull the 2nd centering plate as far as possible outward over the moveable ring so that the measuring mandrel can still be turned by hand.
- Turn the measuring mandrel using the dial gauge extension contacts the magnetic plate 50 mm diameter and the maximum runout is displayed. The measured value is dimension "e" (red range of numbers).
• Example: Dimension "e" = 1.60 mm
Determining shim thickness S3
"S3" = e - r
Example:
- Select the shim(s) as exact as possible according to the table.
Available Shims for S3
- Remove the universal measuring mandrel.
- Remove the pinion and the taper roller bearing outer race and install with the measured shim S3 and new spacer sleeve. Refer to => [ Drive Pinion Overview ] Drive Pinion Overview.
- Install the inner race/small tapered roller bearing and tighten the nut on the pinion until the specified friction torque is reached => [ Pinion Nut, Tightening and Friction
Torque, Adjusting ] Service and Repair.
Slowly increase the torque and read the friction torque several times.
The spacer sleeve must be replaced and the adjustment must be performed again if the specified friction torque is exceeded.
A spacer sleeve that has been compressed to far may not be used any longer.
Adjust the following friction torque:
* Driven at least 50 km
Perform a Check Measurement - Check Dimension "r".
- Turn the pinion 8 turns in both directions so that the tapered roller bearings settle in.
Install the universal measuring mandrel (VW 385/1) and measure dimension "r".
If the selected shims are correct, the dial gauge, read counter-clockwise (red number range), must display the value of dimension r with a + 0.05 mm tolerance.
- Tighten the nut.
- Measure and mark the radial run-out on the flange/driveshaft after tightening the nut on the pinion. Refer to => [ Radial Run-Out on Flange/Driveshaft, Measuring and Identifying ] Testing and Inspection.
Ring Gear, Adjusting
(Adjusting the differential)
• The ring gear must be adjusted if the rear axle housing, the final drive cover, the differential tapered roller bearing, the differential housing or the drive train are replaced.
Special tools, testers and auxiliary items required
• Magnetic Plate 50 mm Dia. (VW 385/17)
• Dial Gauge Holder (VW 387)
• Measuring Lever (VW 388)
• Sleeve (VW 521)
• Torque wrench (V.A.G 1331)
• Dial gauge
• M8 x 45 hex bolt
Determine the total Shim Thickness S total for the Shims S1 + S2
(Adjusting the pre-load on the tapered roller bearing/differential).
• The pinion is removed.
• Only when the tapered roller bearing for the differential is being replace may the ring gear be removed from the differential housing. Then is it not necessary to remove the pinion.
- Remove the flange shaft seal using the assembly lever.
- Remove the differential tapered roller bearing and the shims. Refer to => [ Differential ] Differential.
- Install the taper roller bearing outer race all the way into the housing with a 1.00 mm shim (S2 side). Refer to => [ Differential ] Differential.
• A 1.0 mm shim S2 is installed as a preliminary measuring specification. It is identified in the following by S2*. is then replaced by S2 after the torsional backlash is determined.
- Install the taper roller bearing outer race with a shim S1 into the final drive cover.
- Install the differential into the housing.
The ring gear touches the cover side.
- Position the final drive cover and tighten the 4 bolts diagonally to 25 Nm.
- Mount the tools on the differential housing on the transmission housing side.
- Turn the final drive with the cover side upward.
- Turn the differential 8 turns in both directions so that the tapered roller bearings settle in.
- Mount the measuring tools.
- Lay the (VW 385/17) on the differential.
A - dial gauge extension 30 mm
- Install the M8 x 45 bolt - B -.
- Mount the dial gauge extension on the center of the (VW 385/17).
- Set the dial gauge (3 mm measuring range) to 0 with 2 mm preload.
- Lift the differential without rotating it in direction of - arrow -, then read the play on the dial gauge and write it down (example: 0.50 mm).
If it is necessary to repeat the measurement, then the differential must be turned 8 turns in both directions beforehand so that the tapered roller bearings settle in.
Formula: S total = S2* + measured value + bearing preload
Example
Shim thickness S1*
• S1* is then replaced by S1 after the torsional backlash is determined.
• The total shim thickness S total remains unchanged.
Formula: S1* = S total - S2*
Measuring the Torsional Backlash
(Position of the ring gear inside the transmission housing)
• The pinion is installed with shim S3.
• The taper roller bearing outer race is installed into the transmission housing with shims S1* + S2*.
• The differential is installed.
- Mount the final drive cover and tighten the bolts to 25 Nm.
- Turn the differential 5 turns in both directions so that the tapered roller bearings settle in.
- Mount the measuring tools.
- Install the dial gauge with the dial gauge extension (VW 382/10) (6 mm).
Set the (VW 388) to dimension a = 60 mm.
Determine the play between the tooth flanks as follows:
- Turn the ring gear until it touches one of the tooth flanks.
- Set the dial gauge to 0 with 2 mm preload.
- Turn back the ring gear until it touches the opposite tooth flank (torsional backlash).
- Read the torsional backlash and write down the measured value.
- Turn the ring gear 90° and repeat the measurement 3 times.
Determining the Average Torsional Backlash
- Add the 4 measured values and divide the total by 4.
• Result: the average torsional backlash 1.16 : 4 + 0.29 mm.
• If, during the measuring, the individual values deviate by more the 0.06 mm from each other, the ring gear or the drive train were installed incorrectly. Check the assembly and replace the drive train if necessary.
Determining the shim thickness S2
Formula: S2 = S2* - torsional backlash + lift
• The thickness can be determined by inserting one or two shims.
Determining the Shim Thickness "S1"
Formula: "S1" = "S total" - "S2"
• The thickness can be determined by inserting one or two shims.
- Install the shims S1 on the ring gear side and S2 opposite the ring gear. Install 2 shims if necessary.
Check Measurement
- After installing the shims S1 and S2, turn the differential 5 turns in both directions so that the tapered roller bearings can settle in.
- Measure the torsional backlash 4 times.
• Specified value: 0.12 - 0.22 mm.
• If the torsional backlash is out of the tolerance, then the adjustment must be repeated. The total shim thickness S total must not change.
• The individual measured values may deviate maximum 0.06 mm from each other.