Volkswagen Workshop Service and Repair Manuals

Adjusting bevel gear (with stub shaft)

Special tools and workshop equipment required

t	Gearbox support -VW 353-

t	End dimension plate -VW 385/17-

t	Universal dial gauge bracket -VW 387-

t	Adjustable measuring lever -VW 388-

t	Adjusting device for crown wheel -VW 521-

t	Dial gauge

Readjustment of the bevel gear (with stub shaft) is required if t  Rear final drive housing t  Tapered roller bearing for bevel gear with stub shaft t  Cover or the t  Final drive gear set is renewed. Adjustment overview → Chapter Adjust preload of tapered roller bearing for bevel gear (with stub shaft). The shaft bevel gear is removed. –  Fit 1.0 mm shim in small tapered roller bearing outer race seat (S2 side). As a test condition, a temporary shim S2 of 1.00 mm is installed. It is referred to below as S2. After backlash is determined, S2* is replaced with final shim S2. –  Press in outer race → Anchor. –  Fit bevel gear with stub shaft with tapered roller bearing. –  Install cover with large tapered roller bearing outer race but without O-ring, flange shaft seal and without shim S1.

–  Attach dial gauge and set to “0” with 2 mm preload. –  Move bevel gear with stub shaft up and down (direction of arrow). –  Read play from dial gauge and determine Stotal. Example: "Stotal" = S2* + measured value + preload

Fitted shim(s) S2*		1.00 mm
Measured value (example)		0.90 mm
Preload (constant value)		0.30 mm
Stotal		= 2.20 mm

Determine thickness of shim S1.   Note t  After backlash is determined, temporary shim S1* is replaced with final shim S1. t  The total shim thickness "Stotal" remains unchanged. S1 = Stotal - S2 Example:

Total shim thickness "Stotal"		2.20 mm
Fitted shim(s) S2		- 1.00 mm
Thickness of shim S1		= 1.20 mm

Available shims for S1 → Anchor. Measure backlash. Pinion housing with shaft bevel gear and S3installed Install bevel gear with stub shaft: S1 is installed on the cover side and S2 in the rear final drive housing.

–  Set up measuring tools. t  Dimension “a” = 43.5 mm t  Screw in adjustable measuring lever -VW 388- so that dial gauge extension is at right angles to surface to be measured. –  Turn bevel gear with stub shaft to stop. Set dial gauge to 0, turn back bevel gear with stub shaft and read backlash. Note reading. –  Loosen clamping sleeve locking screw and after turning bevel gear with stub shaft a further 90°, repeat complete measuring process 3 more times. Add the four results and calculate the average backlash. Calculating average backlash. Example:

	1. Measurement	0.30 mm
+	2. Measurement	0.31 mm
+	3. Measurement	0.30 mm
+	4. Measurement	0.29 mm
Total		1.20 mm

Average backlash: 1.20 mm / 4 = 0.30 mm. Determine thickness of shim S2.

S2	=	Inserted shim
	-	Average backlash
	+	Lift (constant value)

Lift = 0.20 mm Example:

S2	Inserted shim	1.00 mm
-	Average backlash	0.30 mm
		0.70 mm
+	Lift (constant value)	0.20 mm
S2	=	0.90 mm

Note Allocate shims using → ETKA (electronic parts catalogue). Available shims for S2

Shim thickness (mm)
0.65	0.90	1.15
0.70	0.95	1.20
0.75	1.00	1.25
0.80	1.05
0.85	1.10

–  Install determined shim S2 in place of S2.*. Two shims which total the measured value may be installed. –  The various thicknesses make it possible to achieve the exact shim thickness required. –  Press outer race in again and fit bevel gear with stub shaft. Determine thickness of shim S1.

S1	=	Stotal - S2
Example:
S1	=	2.20 mm - 0.90 mm
S1	=	1.30 mm

Note Allocate shims using → ETKA (electronic parts catalogue). Available shims for S1

Shim thickness (mm)
0.65	0.90	1.15
0.70	0.95	1.20
0.75	1.00	1.25
0.80	1.05
0.85	1.10

–  Allocate shim(s) using electronic parts catalogue. –  Insert determined S1 shim. Two shims which total the measured value may be installed. –  Various tolerances make it possible to obtain the exact shim thickness required. –  Press outer race in again. –  Fit cover. Carrying out control measurement - measure backlash. –  It must be 0.12…0.20 mm.