Adjusting bevel pinion — VW

Special tools and equipment required

Measuring device VW 382/7
Dial gauge (measuring range 10 mm)
Caliper gauge
Torque gauge (commercially available 0 - 600 Ncm)

Adjusting master 2021

Note:

From 01.97 the end face machining of the bevel gear has been modified in production on certain final drives. Surface grinding is not used anymore, therefore notches and projections remain on the end face which lead to measuring errors when adjusting. The magnetic plate from VW 385 is also to be used for such bevel pinions and its thickness also taken into account when calculating the adjustment dimensions

It is necessary to readjust the drive pinion if the

Rear axle casing
Taper roller bearings for bevel pinion

or

Drive set

are replaced.

Install bevel pinion without adjustment shim with old spacer sleeve S3 => Page
39-50
, assembling rear final drive.
Adjust a friction torque of 250...300 ncm at the collared nut using torque gauge -2- and a bihexagonal nut -1-. (seal installed.)
Measure and note the outside diameter of the bearing outer race of the differential bearings using a caliper gauge.

Example: 89.05 mm

This gives the radius of the outside diameter as follows:
rbearing = Dbearing : 2
rbearing = 89.05 mm : 2 = 44.53 mm

The required length of the adjusting master "L" can now be determined with the basic dimension Ro = 66.00 mm:
L = Ro + rbearing
66.00 mm + 44.53 mm = 110.53 mm

Insert bearing outer race and set dial gauge (10 mm measuring range) on "0" with 2 mm preload on the highest point of the bearing outer race (dial gauge extension - 15 mm long)

Note:

The outer surfaces must be clean and free from burrs. Only place measuring bridge on a paint-free surface.

Mount adjusting master 2021 on the end face of the bevel pinion and measuring the difference to the bearing outer race. The value measured is the dimension "e". Example: 1.35 mm

Determining thickness of adjustment shim "S3":

Note:

Given the required length "L", the adjusting master 2021 is too long for the differential of the type used here (selection of "Ro" and bearing diameter on differential). Therefore this is to be taken into account as a tool correction dimension "W" as shown in the example.

W = (Length of 2021) - L

W = 114.7 mm - 110.53 mm = 4.17 mm

S3 = e + W + r

e = Value determined

W =Tool correction dimension: 4.17 mm

r = Difference from basic dimension Ro (66.00 mm) and the dimension R specified on the drive set.

Note:

The value "r" is positive for R dimensions less than 66.00 mm and negative for R dimensions greater than 66.00 mm.

Example:

e = 1.35 mm

W = 4.17 mm

r = -0.04 mm

S3 = 135 mm + 3.95 mm - 0.04 mm

S3 = 5.48 mm

Notes:

The adjustment shims S3 are supplied in thicknesses between 5.12 mm and 5.80 mm.
Allocate adjustment shims in accordance with the parts catalogue.

Any thickness can be measured for "S3" due to the tolerances of the adjustment shims.

Measure adjustment shims again at several points with a micrometer. In addition, check shims for burrs or damage.

Only install perfect shims!

Carrying out verification measurement

Install bevel pinion with adjustment shim "S3" => Page
39-50
, assembling rear axle.

When the adjustment shim "S3" is correctly selected the dial gauge must now (after subtracting W; 4.17 mm in example) display the value of the marked deviation "r" with a tolerance of ±0.04 mm.
Note the friction torque measured when installing the collared nut without differential for the following adjustment of the differential.