Compressor drive unit, checking, replacing

WARNING: This page does not describe the selected car, but rather 17 other vehicles, including the 2009 Audi S4, 2009 Audi A4, 2008 Audi S4, 2008 Audi RS 4, and 2008 Audi A4. However, it is still accessible from the selected car via links, so may be relevant.

Replacement involves removing compressor → Compressor, removing and mounting (vehicles with 4 or 6-cyl. engine) .

NOTE:

If drive plate overload safeguard has been triggered, check freedom of movement of compressor before replacing drive unit. Replace entire compressor if it is stiff.

Fig 1: Compressor Drive Unit, Checking, Replacing Overview

Courtesy of VOLKSWAGEN UNITED STATES, INC.

1 - Compressor drive shaft

Check; after tightening threaded connection, drive shaft must engage snugly in splines of drive pinion → Compressor drive shaft, removing and installing
Tightening torque 60 Nm
Loosening and tightening → Compressor drive shaft, loosening and tightening
Removing and installing → Compressor drive shaft, removing and installing

Lubricate drive pinion splines with special grease G 000 100

2 - Socket-head bolt

Tightening torque 10 Nm

3 - Drive plate

With overload safeguard, triggered in the event of excessive torque (e.g. stiff compressor) and drive shaft just free-wheels without driving compressor
Checking run-out and adjusting → Run-out of drive plate with overload protection, checking and adjusting
Removing and installing → Drive plate with overload protection, removing and installing

4 - Drive plate

Threaded to compressor drive shaft
With overload safeguard, triggered in the event of excessive torque (e.g. stiff compressor) and drive shaft just free-wheels without driving compressor
Tightening torque 30 Nm
Removing and installing → Drive plate to compressor, removing and installing

5 - Rubber element

Isolates drive unit, damps vibration and sound
When installing, moisten rubber elements slightly with soap solution for example to provide lubrication
Removing and installing → Drive plate to compressor, removing and installing

6 - Spacing disc

Genuine spacer must be installed
Dimensions: 17.5 x 10 x 3 mm

7 - Securing ring

Replace
Ensure correct positioning (flat side facing compressor)
Removing and installing → Drive plate with roller bearing, removing and installing

8 - Drive plate

With rolling bearing
Removing and installing → Drive plate with roller bearing, removing and installing
Clean compressor flange before installing drive plate

9 - Compressor

Different models may be installed depending on engine and country version