Drive Pinion And Ring Gear, Adjusting
Drive pinion and ring gear, adjusting
Note:
^ Drive pinion and ring gear must be very carefully adjusted to ensure long service life and smooth running. At the factory, drive pinion and ring gear are adjusted relative to each other to ensure smooth running and low noise in both directions. The location for the smoothest running is determined by moving drive pinion axially whereby ring gear is moved far enough out of the backlash-free position so that the backlash is within specified tolerances.
^ The goal of the adjustment is to reproduce the setting for the quietest possible running, as obtained on the test machine during production.
^ The deviation, or tolerance "r" which is based on the master gauge "RO" is measured for the final drive sets supplied as replacement parts and marked on the outer circumference of the ring gear. Every drive pinion set drive pinion and ring gear- may only be replaced together.
^ Follow general repair notes for tapered roller bearings and shims.
^ Make sure that all installation and measurement procedures are performed with the utmost care and cleanliness to ensure a successful result.
Gear set, adjusting and marking
1. Identification - "0937" means the Oerlikon gear set with a ratio of 37: 9.
2. Pairing number (312) of gear set.
3. Dimension "r" is based on the master gauge used on the test bench during production. Dimension "r" is always given in 1/100 mm. Example: "25" means r=0.25 mm Ro - Length of test machine master gauge used Ro - ring gear = 57.50 mm R - Actual dimension between ring gear axis and face of drive pinion in position of quietest running for this
gear set R=Ro + r Vo - Hypoid offset
Gear set, adjusting sequence
If drive pinion and gear ring have to be adjusted, the following sequence is recommended for maximum efficiency:
1.) Determine total shim thickness "Stot" for S1 + S2 for the specified pre-tension of tapered roller bearings for differential.
2.) Determine total shim thickness "S3" so that the drive pinion is installed in the same location as on the test machine during production.
3.) Distribute total shim thickness Stotal S1 + S2, so that the specified backlash between ring gear and drive pinion is maintained.
Note: Overview of components and shims.
Adjustment overview
Note: When working on the transmission, the drive pinion or gear set only needs to be adjusted if components were replaced which directly influence the final drive. Use the following table to prevent unnecessary adjustments:
Shim location
Note: List of adjustments when replacing individual components of transmission.
S1 - Adjustment shim for ring gear in final drive cover
S2 - Adjustment shim for ring gear in final drive cover
S3 - Adjustment shim for drive pinion in final drive cover
Special tools and equipment
^ VAG 1383A Engine/transmission hoist
^ VAG 1359/2 Universal mount
^ VW385/1 Measuring bar
^ VW385/2 Plastic piece
^ VW385/3 Plastic piece
^ VW385/14 Measuring rod
^ VW385/15 Extension pin
^ VW385/17 Magnetic plate
^ VW385/30 Master gauge-adjustable
^ VW385/33 End gauge
^ VW387 Dial gauge holder
^ VW388 Measuring lever
^ VW401 Thrust plate
^ VW402 Thrust plate
^ VW408A Punch
^ VW457 Support channels
^ VW521/4 Locking sleeve
^ VW521/8 Bushing
^ VW540 Holding fixture
^ 30-205 Thrust pad
^ 2003/3 Seal installer
^ 3005 Thrust pad
^ 3028 Retainer
^ 3062 Thrust pad
^ 3253 Wheel bearing assembly set with 3253/3 and 3253/4
^ Dial gauge extension 30 mm
^ Dial gauge
^ Torque gauge (0-600 Ncm)
Drive pinion, adjusting
Note:
^ Before adjusting drive pinion, adjust ring gear (determine total shim thickness Stotal S1+S2).
^ Drive pinion only has to be adjusted if gear set, tapered roller bearings for drive pinion of final drive housing was replaced. List of adjustments.
^ Do not grease new tapered roller bearings additionally for friction torque measurement. The bearings are already greased with a special oil from the factory.
Determining Shim "S3"
(adjust preload of tapered roller bearing for drive pinion)
^ Clamp final drive into assembly fixture.
^ Install double tapered roller bearing outer race without shim into housing.
Note: On 3253/4 pressure disc, marking "Open" points toward nut on installation device
^ Pull small tapered roller bearing outer race into housing.
^ Install oiled outer race using VW408A punch and 30-205 thrust pad
^ Install drive pinion without spacer sleeve.
^ Heat tapered roller bearing inner race to 100°C and install on drive pinion.
CAUTION! Wear protective gloves.
Note:
^ Do not grease new tapered roller bearings additionally for friction torque measurement. The bearings are already greased with a special oil from the factory.
^ Only install spacer sleeve if friction torque has been adjusted (Shim S3 already determined).
A - Standard torque gauge, 0 to 600 Ncm B - 36 mm socket insert
Note: If necessary use 314" to 112" reducing piece.
^ Bolt in 3028 retainer using two hex bolts M8 x 30 -A-.
B - 36 mm long socket
^ Tighten drive pinion nut to achieve following friction torque:
When nut is tightened, final drive must be supported (e.g. using VAG 1359/2 universal mount together with VAG 1383A transmission hoist).
^ Install adjustment ring from VW385/1 measuring bar.
^ Dimension a = 60 mm
^ Adjust sliding adjustment ring.
^ Dimension b = 55 mm
^ Complete measuring bar as shown in illustration.
^ VW385/15 extension pin 9 mm
^ VW385/30 master gauge, adjusting:
^ Ro = 57.50 mm
- Set dial indicator (3 mm measuring range) to 0 with 2 mm preload.
Note: Turn differential at least 5 rotations in each direction to seat the tapered roller bearings. Otherwise, measurement will result in false readings.
^ Install VW385/33 end gauge at drive pinion head.
^ Remove master gauge and insert measuring mandrel into housing.
^ VW385/3 plastic piece faces final drive cover
^ Install cover for final drive and tighten four bolts.
^ Using adjustable ring, pull 2nd centering disc out far enough, so that the mandrel can only just be turned by hand.
Determining dimension "e"
^ Turn measuring mandrel until dial indicator plunger tip touches end gauge on pinion shaft head and measure maximum run-out (return point). Measured value is dimension "e" (red numbered area).
^ Measured value in the following example: "e" = 1.60 mm
Note: Dimension "e" is required to determine thickness of S3 shim.
^ After removing universal mandrel, and with VW385/30 master gauge in place, check dial indicator again to see if it indicates O with 2 mm preload. If not, repeat measurement.
Determining thickness of shim "S3"
Formula:
"S3" = "e" minus "r" e = determined value r = deviation (indicated in
1/100 mm on ring gear)
Example:
Determined value "e" 1.60 mm
Deviation "r" 0.42 mm
Thickness of shim "S3" 1.18 mm
^ Determine shim as closely as possible according to table.
Available shims for S3
^ Remove universal mandrel.
^ Remove drive pinion and large tapered roller bearing outer race and install together with determined shim S3 and spacer sleeve from.
^ Insert small tapered roller bearing inner race and tighten drive pinion nut until prescribed friction torque is attained.
Note:
^ Do not grease new tapered roller bearings additionally for friction torque measurement. The bearings are already greased with a special oil from the factory.
^ Increase torque slowly and measure friction torque multiple times. If the specified friction torque is surpassed, replace spacer sleeve and repeat adjustment! Any spacer sleeve that has been pressed together too far one time must be replaced.
- Adjust friction torque to following values: