Issue 1 · 2010

AUDISKODAVW

Critical procedures for auxiliary tensioner mountingThis bulletin will focus mainly on two critical procedures when mounting the VKM 31013 auxiliary tensioner. It will also highlight the importance of changing all associated auxiliary components that are included in the VKMA 31020 multi-V belt kit.

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VKMA 31020

CAR MAKER MODEL ENGINE ENGINE CODE

AUDI A4 (8D2, B5)/A4 Avant (8D5, B5)A6/A6 Avant (4B, C5)

1.9 TDI1.9 TDI Quattro AJM, ATJ

SKODA Superb (3U4) 1.9 TDI2.0 TDI

AVF, AWX, AVBBPZ, BSV, BSS, BWW

VW Passat (3B2, 3B3)/Passat Variant (3B5, 3B6) 1.9 TDI1.9 TDI Quattro2.0 TDI

AJM, ATJ, AVBAVF, AWX, BGW, BHW

Vehicle applications – VKMA 31020

A0003

Air Conditioning Pulley

VKMV 4PK855 (Air conditioning belt)

VKM 31059

Crankshaft pulley

VKMV 5PK1432 (Alternator belt)

Power Steering

Alternator

VKM 31013 Tensioner: There are two critical procedures that must be followed when installing this tensioner. One is the correct placement of the O-ring into the unit spacer and the second is the correct fitment of the lower mounting bolt. See the fitting guidelines on the next two pages for further details.

The engine diagram showing the auxiliary system and all of its components.

Viscous- coupling

Critical procedures for mounting the VKM 31013 tensionerCorrect position of the rubber O-ring

The O-ring acts as a shock absorber for the upper mounting bolt. Its design and function is to isolate and reduce any excessive vibrations between the belt system and the engine. The O-ring should be securely located into the spacer opening (see pictures 3 and 4), ensuring there is NO free play between the spacer and the tensioner. This is important, as failure to do so will result in the bolt breaking during normal operation. This breakage will always occur at the threaded end of the upper mounting bolt (see picture 5).

Picture 3 and 4: The O-ring in correct position with no free play.

Picture 2: Bolt, bracket and rubber O-ring.

Picture 6

The position of the lower mounting nylon bush

Now let’s turn our attention to the lower mounting bolt. The VKM 31013 should be inspected upon removal from the box and the correct position of the hydraulic damper should be noted. The correct position of the lower mounting nylon bush can be seen in the tensioner on the right hand side of picture 6. If the lower mount is not aligned as seen in this picture, simply lift the rubber protection bellows, and rotate the hydraulic cylinder until the nylon lip is facing towards you. This is the side that the bolt should be mounted through.

Align the hydraulic cylinder so this side of the nylon lip is facing towards you.

Picture 5: The bolt breakage point.

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Mounting recommendations

It is recommended that the belt tensioner unit be replaced every 55 000 miles. Always replace the whole system at the same time.

Carefully clean all mounting areas on the engine. Position the tensioner in relation to the mounting holes, ensuring there is NO free play between the spacer, O-ring, and tensioner, then HAND TIGHTEN the bolt. Make sure that the tensioner is aligned correctly and then HAND TIGHTEN the lower mounting bolt.

Damage to the tensioner

Failure to install the damper in the correct position will result in the nylon bushing working itself loose, causing damage to the belt system (see pictures 7-10).

VKM 31013 - an assembled unit

To ensure a complete overhaul of the auxiliary tensioner system - SKF offers one complete, ready assembled unit.

Picture 6

Pictures 7-10: Tensioner damage caused by installing the tensioner incorrectly.

ALWAYS follow the manufacturing recommendations on torque specifications. In this case the torque on the upper bolt is 25 Nms. and the torque on the lower mounting bolt is 30 Nms.

Torque at 90°

When applying torque to the upper mounting bolt, it is very important to do so at a 90° angle. This is critical as pulling up at an angle will distort the bolt causing misalignment and consequently excessive vibration in the auxiliary system (see picture 11).

Picture 11

IdlerOE # 038 145 278

Idler boltOE # N 909 782 02

Bracket & boltOE # 038 145 283 A

Hydraulic pistonOE # 038 145 299 A

Hydraulic piston boltOE # N 010 244 16

When changing the VKM 31013 tensioner, do not take any risks! For a complete and professional repair, change all of the associated auxiliary components that SKF include in the VKMA 31020 multi-V belt kit.

As seen in the diagram on page 1, all of the auxiliary system components are driven by auxiliary belts. The OE belt length is a key feature when servicing the auxiliary drive system and ensures that the belt is the correct length, down to the exact millimeter, which ensures a good repair and a trouble free performance!

An incorrect belt length (i.e. shorter or longer), leads to the incorrect tension of the auxiliary system. This can cause a number of problems for your customer – from a noisy drive belt to the possibility of a complete, premature failure of the drive belt, which in itself can cause engine failure if the auxiliary drive belt was to enter the timing drive system!

SKF has the broadest range of auxiliary belts in the aftermarket. More sizes mean more precision. For a perfect fit, ask for SKF.

® SKF is a registered trademark of the SKF Group.

© SKF Group 2010The contents of this publication are the copyright of the publisher and may not be reproduced (even extracts) unless prior written permission is granted. Every care has been taken to ensure the accuracy of the information contained in this publication but no liability can be accepted for any loss or damage whether direct, indirect or consequential arising out of the use of the information contained herein.

PUB 80/I1 10633 EN.GB • 2010

Printed on environmentally friendly paper.

SKF: your one-stop source for auxiliary drive systems

Exact belt length, for a perfect fit

VKMA 31020 multi-V belt kit contentVKM 31013 tensioner VKM 31059 tensionerVKMV 5PK1432 auxiliary beltVKMV 4PK855 auxiliary belt