Aluminum Bolts: Ribbed Belt Pulley Side Sealing Flange - Tightening Specifications and Sequence

WARNING: This page is about a different car, the 2016 Audi A7 Quattro. However, it is still accessible from the selected car via links, so may be relevant.

CAUTION:

Risk of damaging the aluminum bolts when installing the belt pulley side sealing flange.

Aluminum bolts must not be used to tighten the belt pulley side sealing flange to the cylinder block.
For this reason use three M6x20 steel bolts to tighten the belt pulley side sealing flange, as described as follows.

Fig 1: Ribbed Belt Pulley Side Sealing Flange Tightening Sequence (Aluminum Bolts) (1 Of 3)

Courtesy of AUDI OF AMERICA, LLC

-- Tighten the bolts in 11 stages as follows:

Steps 1 to 3:

Step	Bolts	Tightening Specification
1.		Attach the sealing flange with the seal to the cylinder block
2.	-1-	Tighten for the idler roller -Item 6- OVERVIEW - CYLINDER BLOCK, BELT PULLEY SIDE
3.	-2, 3, 4-	Tighten the M6 x 20 steel bolt to 9 Nm

Steps 4 to 8:

Fig 2: Ribbed Belt Pulley Side Sealing Flange Tightening Sequence (Aluminum Bolts) (2 Of 3)

Courtesy of AUDI OF AMERICA, LLC

Step	Bolts	Tightening Specification/Additional Turn
4.		Insert an engine oil cooler thermostat with cover
5.	-10-	Install by hand all the way
6.	-1 to 19-	3 Nm
7.	-1 to 19-	3 Nm - this measurement accounts for the belt pulley side sealing flange shrinkage
8.	-1 to 19-	90° additional turn

Steps 9 to 11:

Fig 3: Ribbed Belt Pulley Side Sealing Flange Tightening Sequence (Aluminum Bolts) (3 Of 3)

Courtesy of AUDI OF AMERICA, LLC

Step	Bolts	Tightening Specification/Additional Turn
9.	-2, 3, 4-	Remove the M6 x 20 steel bolts
10.	-2, 3, 4-	Insert the aluminum bolts and tighten to 3 Nm
11.	-2, 3, 4-	Turn the aluminum bolts a 90° additional turn