Setting Proper Audi VW 4.2L V8 Timing Belt Tension
Four (4) customer questions are discussed in this bulletin regarding the proper timing belt tension on the Audi and VW 4.2L engine as used for the models shown below.
Audi A6 Timing Belt Kit - 2001-04 w/ 8 Cylinder 4.2L Engine Code AWN
Audi A8 Timing Belt Kit - 2001-03 w/ 8 Cylinder 4.2L Engine Code AKB or AUX
Audi A8 Timing Belt Kit - 2004-06 w/ 8 Cylinder 4.2L Engine Code BFM or BGK
VW Phaeton Timing Belt Kit - 2004-06 w/ 8 Cylinder 4.2L Engine
VW Touareg Timing Belt Kit - 2004-07 w/ 8 Cylinder 4.2L Engine
Part Numbers: GH21118, GH21118-1
Question 1) The instructions for installing the kit leaves the timing belt so tight it appears to bind the water pump and hydraulic damper. Will this create a potential failure of these parts? Should the tension be loosened a bit?
25) Insert a 5mm drill bit between the hydraulic damper piston and the tensioner pulley casting arm. Allow the tensioner pulley casting arm to rest on the 5mm drill bit. (Image 9)
26) Using eccentric tool T40009 rotate eccentric tensioner pulley counter clockwise until the arm of tool T40009 is aligned with the center of the water pump pulley and torque to 16 ft lbs. (Image 10) When doing this step make sure the 5mm drill bit is still properly in place as outlined in the previous step.
27) Remove the 5mm drill bit from between the hydraulic damper piston and the tensioner pulley casting arm.
28) Compress hydraulic damper, remove damper holding pin, and allow damper to un-compress. You will want to allow the hydraulic damper to un-compress thoroughly for best belt tension.
Note 1) After removing the damper holding pin, a 5-7mm distance between the top of hydraulic damper body and the tensioner pulley casting arm should be maintained.
Question 2) Does having tight 4.2L V8 timing belt tension effect the longevity of the timing belt components?
Answer: The Graf O.E.M. water pumps used in our kits have been engineered with a large enough displacement sized OEM bearing to carry the heavy load that the timing belt is applying to it. With proper timing belt tension procedures followed the water pumps are designed to exceed the factory service intervals.
Question 4) Does your kit contain aftermarket belts?
Answer: The INA - Gates 4.2L V8 timing belt in these kits should NOT be considered 'aftermarket'. INA - Gates is an OE supplier to many automotive manufacturers for a variety of models.
We would like to encourage installers to read the entire instructions ahead of time and then to take the time to correctly follow the instructions for a failure-free installation. If you have unanswered questions during the repair process, feel free to contact us.