Spur Gear Tapered Roller Bearing Pre-Load, Determining

Special tools and workshop equipment required

Measuring Set - Magnetic Plate - 50mm VW385/17 from Measuring Set VW385
Dial Gauge Holder VW387
Crown Wheel Adjusting Tool VW521
Dial Gauge Extension from Dial Gauge Adapter 2066

Determine the new adjusting shim "S₅ "

This adjustment is necessary when replacing the following parts:

Transmission cover
Center differential housing
Gear Carrier
Spur gear
Tapered roller bearing on the spur gear

The outer race/tapered roller bearing for the gear wheel mounting is installed inside the transmission cover.
The outer race/tapered roller bearing with adjusting shim for the gear wheel mounting is installed inside the gear carrier. A 0.85 mm adjusting shim "S₅ *" must be used (part number 012 409 387 ED) for measuring.

NOTE:

A 0.85 mm thick adjusting shim "S₅ " is used temporarily for the initial measurement. It is designated as "S₅ *" in the following. After determining the bearing pre-load, "S₅ *" is replaced by final "S₅ ".

-- Install the spur gear in the transmission cover.

Install the gear carrier on the transmission cover as follows:

Fig 1: Coat Both Outer Ring Surfaces On Gear Carrier Slightly With Transmission Fluid

Courtesy of AUDI OF AMERICA, LLC

Installed position: the tab -arrow A- on the gear carrier must installed into the opening -arrow B- inside the transmission cover.

-- Attach the center differential housing -C- to the transmission cover using the bolts -A-, -B- and -arrows- (quantity: 5).

Fig 2: Attaching Center Differential Housing To Transmission Cover Using Bolts

Courtesy of AUDI OF AMERICA, LLC

NOTE:

Not all versions have the double bolts -B- ; allocation.

-- Then set the transmission cover with the attached center differential housing in vertical position making sure the center differential housing is facing downward.

-- Install the measuring tools.

Fig 3: Attaching VW 387 In Hole In Transmission

Courtesy of AUDI OF AMERICA, LLC

-- Attach the Dial Gauge Holder VW387 to the hole in the transmission cover using a bolt -B- and nut.

-- Place the Dial Gauge Extension on the center of the Measuring Set - Gauge Block VW385/37.

-- Set the dial gauge (3 mm measuring range) to >>0<< with 2 mm pretension.

-A- Dial Gauge Extension from Dial Gauge Adapter 2066

-- Move the spur gear up and down using the Crown Wheel Adjusting tool VW521.

-- Read the play on the dial gauge.

Example:

0.26 mm

Example:

Inserted shim S₅^*	0.85 mm
Measurement result (example)	+ 0.26 mm
Preload (constant value)	+ 0.10 mm
Adjusting shim S₅ thickness	= 1.21 mm

NOTE:

Allocate adjustment shims.

-- Shim thickness "S₅ " in this example is 1.21 mm.