Drive Pinion, Adjusting
Drive pinion, adjusting
Special tools and workshop equipment required
^ Crankshaft seal installing tool VW 204 B Crankshaft seal installing tool
^ VW 296 Oil seal extractor
^ VW 385 Universal measuring tool
^ VW 387 Universal dial gauge holder
^ VW 401 Thrust plate
^ VW 407 Thrust tool
Special tools and workshop equipment required
^ VW 519 Tube
^ VW 792 Assembly device
^ 3005 Thrust plate
^ 3128 Puller
^ 3301 Assembly equipment
^ V.A.G 1331 Torque wrench
Re-adjustment of the drive pinion is only necessary if the final drive set, tapered roller bearing for drive pinion or transmission housing is replaced.
The object of the adjustment is to reproduce the setting for quietest possible running, as obtained on the test machine in production. Maximum care and cleanliness are essential when performing repairs and taking measurements for achieving good results.
Determining total shim thickness "Stotal" for shims "S3" + "S4"
(adjusting pre-load of tapered roller bearing for drive pinion)
^ Differential removed.
- Without shims press large tapered roller bearing outer race into transmission housing.
- Insert rubber disc -item 40 - and pressure plate -item 39 - into transmission cover.
- Press small tapered roller bearing outer race together with a 1.00 mm thick preliminary shim S4* into transmission cover.
Note: A shim "S4" with a thickness of 1.0 mm is installed for initial measurements. It is referred to as S4* in the following. After determining measurement "e", "S4" will be replaced by the correct shim "S4".
- Pressing on inner race for tapered roller bearing.
- Secure lower tapered roller bearing (arrow).
Note: Illustration shows drive pinion without gear wheels.
- Insert assembled drive pinion in transmission housing.
- Install transmission cover and tighten bolts to 22 Nm.
- Turn transmission so that transmission cover is downward.
- Press down on face of drive pinion head with lever VW 296 until the tapered roller bearing outer race contacts the transmission cover.
- Continue pressing on face of drive pinion head, at the same time turn drive pinion 8 turns by hand, so tapered roller bearing can settle.
- Install dial gauge (3 mm measuring range) and set to "0" with 2 mm pre-load.
Note:
^ Use dial gauge extension 30 mm long.
^ The dial gauge extension must contact the machined surface on the face of pinion.
^ Turn transmission 180° so that the transmission cover is upward.
^ Rotate drive pinion 5 turns in both directions to settle the tapered roller bearing.
^ Read play on dial gauge and note reading.
^ Measurement in example: 0.45 mm
Note: If the measurement has to be repeated, drive pinion must first be rotated another 5 turns in each direction to settle the tapered roller bearing. Reset dial gauge to "0" with 2 mm pre-load.
Formula: =
"Stotal" "S4" + measurement + bearing pre-load
Example:
Inserted shim "S4" 1.00 mm
+ Measurement (example) 0.45 mm
+ Bearing pre-load (constant) 0.15 mm
= Total shim thickness "Stotal" for "S3" + "S4" 1.60 mm
Determining thickness of preliminary shim S3*
Formula:
"S3*" "Stotal" - "S4"
Example: Total shim thickness "Stotal" for "S3" + "S4" 1.60 mm
- Inserted shim "S4" 1.00 mm
=Thickness of shim "S3" 0.60 mm
- Extract large tapered roller bearing outer race.
- Insert preliminary shim S3* into transmission housing and re-install outer race.
- Insert assembled drive pinion in transmission housing.
- Install transmission cover and tighten bolts to 22 Nm.
Checking pre-load of tapered roller bearing for drive pinion
- Rotate drive pinion 5 turns in both directions to settle tapered roller bearing.
Note:
^ If drive pinion cannot be turned by hand, insert a bolt M 10 x 20 in drive pinion head and turn pinion by using a tool on this bolt.
^ Remove bolt again.
- Install measuring tools and secure with bolt (arrow) to transmission housing.
- Position dial gauge (3 mm measuring range) center on transmission cover and set to 0 with 2 mm pre-load.
- Loosen transmission cover bolts and turn drive pinion several times.
- If correct shims have been selected dial gauge will now indicate following value:
^ 0.05... 0.15 mm
- Retighten transmission cover bolts to 22 Nm.
- Remove measuring tools.
- Secure bolt M 10 x 20 on drive pinion head and turn drive pinion 8 turns to allow tapered roller bearing to settle.
- Remove bolt.
Determining dimension "e"
Note: Measurement "e" is required to determine the final shim thickness of "S3" and "S4".
- Set adjustment rings of universal mandrel VW 385/1 to following measurements:
^ Dimension a = 35 mm
^ Dimension b = 75 mm
- Assemble universal mandrel VW 385/1 according to illustration.
- Set master gauge VW 385/30 to Ro according to ring gear diameter and install onto mandrel.
Ring gear diameter 180 mm Ro = 59.65 mm
Ring gear diameter 170 mm Ro = 54.95 mm
- Set dial gauge (3 mm measuring range) to zero with 2 mm pre-load.
- Place end measuring plate on face of drive pinion head.
Note: Make sure plate contact surface fits exactly and is free of oil.
- Remove master gauge and insert measuring mandrel in housing.
^ With Ro = 54.95 mm, a dial gauge extension = 6.5 mm length must be screwed in instead of dial gauge extension VW 385/15.
^ The dial gauge faces cover for final drive
- Install cover for final drive and tighten 4 bolts to 22 Nm.
- Using sliding setting ring to pull 2nd centering disc outward until mandrel can still be turned by hand.
- Turn mandrel until the dial gauge point touches the end measuring plate on drive pinion head, then measure maximum deflection (return point).
^ Measurement in following example: "e" = 0.26 mm (in red scale on dial)
Note: After removing universal mandrel check again that the dial gauge, with master gauge VW 385130 in place, indicates 0 with 2 mm pre-load.
Determining thickness of shim "S3"
^ If dial gauge reading is in red scale, subtract dimension "e".
^ If dial gauge reading is in black scale, add dimension "e".
^ The deviation "r", which is related to 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.
Formula:
"S3" = "S3*" + "r" + "e"
("e" in black scale)
"S3" = "S3*" + "r" - "e"
("e" in red scale)
Example:
Inserted shim "S3" 0.60 mm
+ Deviation "r" 0.38 mm
- Determined value "e" (red scale) 0.26 mm
= Thickness of shim "S3" 0.72 mm
-Determine shim(s)) as accurately as possible from table. Part numbers
The following shims are available for "S3"
Determining thickness of shim "S4"
Formula:
"S4" = "Stotal" - "S3"
Example:
- Determine shim(s)) as accurately as possible from table. Part numbers
The following shims are available for "S4".
Performing check measurement
Checking dimension "r"
- Install drive pinion with determined shims "S3" and "S4" and turn 5 turns in both directions.
- Insert universal mandrel Determining measurement and perform check measurement.
- Read off dial gauge counterclockwise (red scale).
^ If the shims have been correctly selected, the deviation r (marked on outer circumference of ring gear) must be shown within a tolerance of ± 0.04 mm.
Re-determining "S4" shim when installing new transmission cover
Special tools, testers and auxiliary items required
^ VW 387 Universal dial gauge holder
^ VW 792 Assembly device
^ Dial gauge
^ Dial gauge extension
- Use depth gauge to within at least 5/100 mm.
- Clean housing flange.
- Measure difference in depth a on old and new transmission cover.
Example:
Depth a on old transmission cover 257.40 mm
Depth a on new transmission cover 257.55 mm
= Difference 0.15 mm
- Install thicker shim "S4" if new transmission cover is deeper.
- Install thinner shim "S4" if the old transmission cover is deeper.
Example:
Previous shim "S4" 0.95 mm
+ Difference 0.15 mm
= New "S4" shim 1.10 mm
Available shims go to table.
- Install outer race for tapered roller bearing with shim S4 in transmission cover.
- Insert completely assembled drive pinion in transmission housing again.
- Install transmission cover and tighten bolts to 22 Nm.
Checking pre-load of tapered roller bearing for drive pinion
- Rotate drive pinion 5 turns in both directions to settle the tapered roller bearing.
Note: Drive pinion can be rotated by simultaneously turning both flange shafts.
- Install measuring tools and secure with bolt (arrow) to transmission housing.
- Position dial gauge (3 mm measuring range) center on transmission cover and set to "0" with 2 mm pre-load.
- Loosen transmission cover bolts and turn drive pinion several times.
If the correct shims have been selected the dial gauge will now indicate the following value:
^ 0.05... 0.15 mm
- Remove measuring tools.
- Apply thin coat of sealant AMV 188 001 02 to sealing surfaces.
- Retighten transmission cover bolts to 22 Nm.