Timing belt replacement for 1.9l PD TDI engine. (Articles)

Step-by-step:

Timing belt replacement for Golf IV 1.9l PD TDI (here MKB AXR)


This guide has been created to the best of our knowledge. The author assumes no liability for damages.
Changing the timing belt is not a magic trick. Nevertheless, a certain level of technical skill and understanding of engine mechanics should be present.
Furthermore, the special tool for locking the KW and NW is also important. This is available from VW or HAZET.
A device for supporting the engine is advantageous, as the right engine mount needs to be removed. However, it is also possible to support the engine from below using a jack. However, it should also be taken into account that the space underneath the car is also needed (pit, lift).

First, all components below the engine should be removed. Then, the pipes leading to and from the LLK (presumably referring to a specific component) should be disconnected. For some models of the Golf VI, it is advisable to remove the bumper and the right headlight. This provides space to work and the upper LLK connection can be easily dismantled.
Now, the hydraulic lines on the cylinder head need to be disconnected. It is recommended to seal the lines on both sides. The reservoir for the power steering fluid can be easily unscrewed and placed on the CK without disconnecting the lines. The coolant reservoir can also be removed in this way.
Next, the timing belt and its corresponding tensioner must be removed.
Now it gets more difficult! The engine must be hung on the catching device or secured from below. I even recommend installing two fuses in case one fails.
If the engine is attached to the mounting bracket, the right bracket can be removed from both the longitudinal support and the engine bracket. After that, the engine bracket can be removed from the engine. This is not entirely straightforward. The upper screws can only be removed by lifting the engine, while the lower one can only be removed by lowering the engine. Getting the engine bracket out of the engine compartment is a bit tricky. Often, it helps to raise the engine high and rotate the engine mount backward towards the splash shield.
Removing the pulley on the KW and the two remaining ZR covers is a piece of cake. Now the entire ZR assembly is exposed. It is best to move the engine and the NW (water pump) close to OT1. Be sure to only rotate the engine in the correct direction! OT1 is quite easy to find. On the KW (kick-out bearing) gear, there is a marking on one of the screw holes for the pulley, this must align with the hole in the oil pump cover. Now the NW (water pump) must be positioned with the indicator window facing upwards. If this window is facing downwards, the KW must be rotated one more time. Ideally, the NW (water pump) marking and the KW (kick-out bearing) stop should now fit into the designated holes. If this is the case (due to the ZR extension), it is initially important to fix the NW with the marking pin to OT1. The KW can then be fixed later after the ZR has been removed. 'In this case, the crankshaft should not be rotated too far, as this could cause the pistons to come into contact with the valves.
Relaxing the belt tensioner is quite simple. There is an 8mm hexagonal hole in the tensioner roll. An Allen key can be inserted here and the tensioner roll can be turned counterclockwise. Now it is possible to fix the belt tensioner with a kind of fork (included in the HAZET factory set) in its relaxed position. Removing the tensioner roll is now possible. The ZR can then be easily removed.
If the tensioner is being replaced (which is recommended), it should now be removed. There is a small idler pulley on the tensioner's mounting bracket that comes with the ZR repair kit. This should now be replaced, and the new tensioner reinstalled on the engine. Now, the three screws on the NW gear are loosened, and the upper part is fully rotated clockwise until it reaches the end of the long holes.
Now the new belt and the tensioning roller are being installed.
The excentric on the tension roller is now rotated clockwise to the stop. To do this, there is a tool from VW that allows the excentric nut to be rotated and fixed. A 28mm wrench can also be used for this purpose. The locking mechanism of the tensioning element can now be removed. Adjusting the tensioning element is quite simple. To do this, the excentric of the tension roller is rotated clockwise until a gap of 4mm (+/-1mm) is created between the tensioning element and the lever on the tension roller. This fixes the tension roller and the three screws on the NW wheel are tightened (25Nm on a cold engine!). The KW stop and the marking pin of the NW can now be removed. The KW will be rotated two turns in the direction of travel. The KW stop will be pushed back into its locking position (KW not to be rotated backwards!) once the OT1 position is reached, thus locking the KW. Now, the marking pin in the NW must also be properly aligned, and the dimensions of the clamping device must also reach 4mm. If either of these requirements is not met, a correction must be made. After that, the control must be repeated again.
Now, let's move on to the assembly.
We begin with the lower and middle ZR protection. Then the pulley and the motor mount. Secure the motor mount to the longitudinal support and the motor mount. After that, the catch device can be removed. To prevent any parts from falling into the ZR compartment, the upper ZR cover should now be installed.
Now, reinstall the coolant reservoir and the hydraulic fluid reservoir. The fuel lines could also be reinstalled. The assembly of the intake system and the lower engine cover should no longer be a problem. Headlights and bumper installed, and the ZR change is complete.

The first time you start the engine after a ZR (presumably referring to a specific type of engine or system) change, it's often accompanied by a feeling of uncertainty, but if everything has been done correctly, nothing happens and the engine starts up perfectly.
Adjusting the valve timing like in a VP engine is not necessary, as the fixed KW-NW locking mechanism automatically determines the valve timing.
If anyone is concerned that the new NW wheel is now attached in a different position with the lower one, that is not a problem. The measurement of the NW wheel's position will be taken on the lower part of the NW wheel, which was securely fixed to the OT using the marking pin. As long as the KW stop and the NW marking pin fit properly into their designated openings, there should be no problems.

Additional Notes:

- If the motor does not have an additional clamping element, the hydraulic clamping device is integrated into the clamping roll. These motors were used from approximately MJ 04 (some also earlier). There, the ZR voltage is set using a pointer on the voltage roller.

- After completing the work, the synchronization angle (angle of rotation) should be checked (e.g., using a VCDS diagnostic system). The synchronization angle indicates how much the camshaft is rotated relative to the crankshaft. The value changes with a warming engine due to the expansion of the cylinder block. If the value is outside the acceptable range, the camshaft should be loosened and the angle of rotation should be corrected.