Service Bulletin: Proper Removal and Installation of Audi A4 Timing Belt Hydraulic Tensioner Damper

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Please Note: The following service bulletin information corresponds to Audi A4 disassembly STEPS 14-17 and reassembly STEPS 37-41. >> Go to our Audi A4 Timing Belt Installation Guide.

DISCLAIMER: Audi A4 timing belt installation is a complex repair procedure and should be performed by experienced automotive technicians, trained in performing proper timing belt installation.

Blauparts recommends that an Audi VW Factory Trained ASE Certified Technician perform timing belt repair. One who has been trained in specific timing belt procedures for your exact Audi A4 engine. This is for your safety and to prevent improper installation by untrained and unqualified installers and technicians, leading to possible engine damage.

Always read the factory service manual safety instructions and guidelines. Always wear safety glasses and other safety items when performing the following repair.

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How to prevent irreversible damage to the Audi A4 hydraulic tensioner damper on 2.8L 30 valve engines?

PERTINENT TO: 1998-2005 Audi Models with V6 2.8L 30V Engines

Please read the following information BEFORE Audi A4 2.8L timing belt service.

Audi A4 Hydraulic Tensioner Damper Guidelines Before Installation

The Audi A4 hydraulic damper must be put in an upright position for at least three (3) hours before installation. This ensures the proper distribution of hydraulic fluid within the damper tensioner. See Image C below to see the correct upright position.

Do not remove the locking pin in the damper without first reading all of the following steps. Audi A4 damper lock pin tool T400011 should only be removed at the appropriate time and in the manner outlined in the accompanying instructions.

If the pin is accidently removed before installation and the damper piston has been released / extended, then a very specific procedure to properly compress the damper piston must be followed. Done improperly, irreversible damage to the hydraulic tensioner damper will occur.

Steps for Proper Audi A4 Hydraulic Tensioner Damper Installation

Follow Closely to Prevent Irreversible Damage

It has been noted that in an effort to save time, some untrained technicians make the mistake of skipping or NOT following the exact and specific sequence of steps required for correct damper installations. Please see our installation instructions for hydraulic damper disassembly STEPS 14-17 and reassembly STEPS 37-41.

Common areas of error:

  • Some choose to skip the use of the camshaft locking bar tool #3391 and the crank locking pin tool #3242. Please see Audi A4 timing belt disassembly steps 14 -17 and reassembly steps 37-41. Please use the factory specified tools.
  • In whole or in part, some have skipped or incorrectly followed steps 11-18 or steps 31-41. Please follow these steps closely.
  • Upon reassembly and during steps 37-41, some skip or forgot to reinstall the camshaft locking bar tool #3391.
  • Following the aforementioned sequence of steps correctly, is crucial to ensure hydraulic tensioner damper reliability!

When the above mentioned crucial steps are not followed, it's likely that the timing belt marks won't line up, being a tooth or several teeth off. This will require back tracking, making multiple attempts to realign the timing belt marks, in order to achieve correct Audi A4 crankshaft / camshaft belt timing position. In these situations and in an attempt to achieve correct engine timing, compressing of the timing belt damper piston shaft (See Image C below) is required. It's during the compression of the damper's piston shaft that you run the highest risk of irreversible damage to the damper.

Compressing The Audi A4 Hydraulic Tensioner Damper Piston

Compressing the Audi A4 timing belt hydraulic tensioner damper is DANGEROUS and can easily result in damage to the damper rendering it unusable. If the piston shaft on the hydraulic tensioner damper is in an extended position (the locking pin tool T400011 was removed), or if compressing the damper piston in an attempt to reset timing belt tensioner timing (re-performing steps 37-41), follow these procedures very carefully!

  • If the damper piston shaft (See Image C below) is in an extended position (locking pin tool T400011 removed) and the damper piston is compressed too rapidly the hydraulic fluid within the hydraulic damper will be transferred out of one internal piston chamber and into another. Internally this causes an incorrect proportion of hydraulic fluid and weakens the damper's force and its ability to apply correct timing belt tension. If this happens, the damper is irreversibly compromised or damaged.
  • Only compress the hydraulic tensioner damper when it is mounted on the engine, as shown in the image below. Never compress a damper piston shaft in the horizontal (sideways) position (i.e. on a work shop bench vise). If the damper is compressed in the horizontal position, this causes an air pocket inside the tensioner damper, resulting in incorrect internal piston chamber fluid transfer and irreversible damage to the damper.
  • Installing a compromised hydraulic tensioner damper can lead to loose timing belt tension and subsequent engine damage. Typically, a compromised or damaged damper is identified by having 5-10 mm of unrestricted piston shaft free play starting from the full extended position. DO NOT use a compromised damper where there is piston shaft free play.

How to Properly Compress the Hydraulic Tensioner Damper Piston Shaft That Has Been Extended (Locking Pin Tool T400011 Removed):

Only compress the hydraulic tensioner damper when it has been mounted on the engine.

With an 8mm Allen wrench and 3/8 drive rachet, as shown, slowly and gently rotate tensioner pulley clockwise.

This will allow the tensioner pin (A) to push upward on tensioner lever (B) and compress the hydraulic tensioner damper shaft (C) until holes are aligned. Then carefully install pin T400011, being sure not to cause shaft scarring (C). An extremely slow and continuous even pressure should be applied when compressing the hydraulic tensioner damper shaft (C).

Take your time (minimum of 5 minutes) when compressing the damper piston shaft. Failure to follow this procedure and compressing the damper too quickly will cause irreversible damage!

Audi A4 Timing Belt Tensioner Damper Installation

How to Properly Set Audi A4 Timing Belt Tension With The Hydraulic Tensioner Damper:

Please see Audi A4 timing belt installation steps 37 - 38.

Once pin T400011 has been carefully removed, slowly rotate tensioner pulley counter clockwise to around 7 ft. lbs. This will allow the hydraulic tensioner damper shaft (C) to extend pushing upward onto tensioner lever (B) and then pushing onto tensioner pulley pin (A), thus applying proper tension to the timing belt. Then, torque tapered camshaft pulleys to 41 ft. lbs.

There is no need to compress the hydraulic tensioner damper to personal tension.

Next, use a 1/2 inch 24mm 12-point socket and rachet to rotate the engine by the crankshaft. Rotate the engine in the clockwise direction two full engine revolutions. This will allow the damper to compress automatically and give the Audi A4 timing belt its proper variable tension.

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