OVERVIEW - BELT PULLEY, A/C COMPRESSOR WITH A/C Clutch -N25-

WARNING: This page is about a different variant/trim than selected.

NOTE:

If overload protection of pulley triggers, check the A/C compressor for ease of motion before replacing the pulley. If the A/C compressor creates friction, replace it completely.

To remove the belt pulley, it is not always necessary to loosen the A/C compressor from the engine. Refer to A/C COMPRESSOR, REMOVING AND INSTALLING ON BRACKET . However there may be not enough space to remove the belt pulley depending on the engine version. If so, loosen or remove the A/C compressor from the engine or loosen the lock carrier from the vehicle and pull it slightly forward to create enough space (easier to perform depending on the vehicle version). Refer to LOCK CARRIER .

Different versions of the belt pulley (with different diameters) may be installed, depending on A/C compressor construction type and engine version. Refer to the Parts Information.

The replacement belt pulley with A/C clutch has a single part number. The belt pulley and the drive plate are held together with one bolt (when the bolt is no longer needed, dispose of it). When the bolt was manufactured, a predetermined amount of a specific grease was applied to the threads in the drive plate; this amount is sufficient for bolting the drive plate to the compressor one time (a drive plate, which has been removed, cannot be reused). Refer to the Parts Information.

Fig 1: Belt Pulley With A/C Clutch -N25- Overview

Courtesy of AUDI OF AMERICA, LLC

Sealing Cap
- Not always present
Clutch Plate
- Tightening specification: 30 Nm
- Always replace
- Attached to the A/C compressor input shaft
  -- Clean the contact surfaces on the clutch plate and belt pulley before installing.
  
  -- Clean the thread on the A/C compressor shaft before installing the clutch plate.
  
  -- Check the gap dimension between the belt and clutch plates and correct it if necessary before tightening. Refer to BELT PULLEY, REMOVING AND INSTALLING, A/C COMPRESSOR WITH A/C Clutch -N25- .
  
  NOTE:
  The thread of the new clutch plate has already been greased with a specific amount of a grease by the manufacturer.
- There are different versions. Refer to the Parts Information
- The overload protection takes over when the torque is excessive (for example, if the A/C compressor runs with resistance) and the belt pulley runs freely without driving the A/C compressor with the A/C Clutch -N25- switched on.
  Removing and installing
  
  -- Hold the compressor shaft -C- tight and turn the clutch plate counter-clockwise in direction of -arrow- with a suitable tool to remove as described for the drive plate on an A/C compressor without an A/C clutch. Refer to BELT PULLEY, REMOVING AND INSTALLING, "Denso" A/C COMPRESSOR, VERSION "1" .
Washer
Spacer
- For adjusting the gap dimension between the clutch and belt pulley
- To check the gap dimension. Refer to BELT PULLEY, REMOVING AND INSTALLING, A/C COMPRESSOR WITH A/C Clutch -N25- .
Circlip
- Always replace
- Install on correct side (flat side toward A/C compressor)
- Be careful not to bend the circlip more than necessary when installing it.
  -- Insert circlip on correct side, the side with beveled insertion edge -C- faces away from A/C compressor (install the flat side facing the A/C compressor).
Belt Pulley
- The belt pulley is sensitive to impact. Be very careful when handling it.
- Clean the flange on the A/C compressor flange before installing the belt pulley.
- There are different versions (depending, for example, on the type of engine). Refer to the Parts Information.
- If it is not possible to remove the belt pulley from the flange on the A/C compressor by hand. Refer to BELT PULLEY, REMOVING AND INSTALLING, A/C COMPRESSOR WITH A/C Clutch -N25- .
Circlip
- Always replace
- Install on correct side (flat side toward A/C compressor)
- Be careful not to bend the circlip more than necessary when installing it.
  -- Insert circlip on correct side, the side with beveled insertion edge -C- faces away from A/C compressor (install the flat side facing the A/C compressor).
Solenoid Coil
- Make sure the bracket for the cable -B- is installed correctly.
- The connector -D- may be attached to the A/C compressor with a bracket, depending on the version.
A/C Compressor
- Depending on engine version and the market, different versions may be installed. Refer to the Parts Information.
- Clean the A/C compressor flange before installing the pulley.
- Clean the compressor shaft thread and then coat the thread lightly with grease.
  NOTE:
  There are different versions depending on the refrigerant (R134a or R1234yf). Refer to the Parts Information.