2.5 tdi aux tensioner fail

[neilA4]

Well got towed home by aa.

Had front end in service position and looks like the bolt that holds the aux tensioner onto the bracket and pivots sheared at the head, then dropped onto the ac belt, then jammed itself between snub mount chewing up the vibration damper, killing ac belt and stalling engine! The aux belt was nearly off too! Car starts ok only tried for a few seconds!

So, I've ordered new bushes and seals and bolts from audi to replace on the oil cooler/pas bracket for the tensioner pivot. Also need new belts and vibration damper. Cambelt changed not long ago.

feeling lucky cambelt didn't get chewed up, anyone replaced these bushes before?

cheers

 

[neilA4]

Closer inspection looks like the alternator clutch pulley has seized which has put stress on the aux vibration damper. So need to replace pulley now doh. Removing the oil cooler bracket was not fun, going to refurb the pivot bushes.

 

[adamss24]

Closer inspection looks like the alternator clutch pulley has seized which has put stress on the aux vibration damper. So need to replace pulley now doh. Removing the oil cooler bracket was not fun, going to refurb the pivot bushes.

As far as i remember alternators on the v6 tdi does not have a clutch pulley... My money is on the wear of the pivoting bushes in the Aux. belt tensioner, the belt does not run true anymore and starts to chew the plastic covers subsequently trowing the belt off. Seen timing belts that jumped because of it failing...

 

[neilA4]

Cheers just saved me some money! I did wonder why the pulley looked hollow. The engine was stalled by the bolt that holds the pivot together shearing and jamming between vibration damper and snub mount!

 

[neilA4]

Pics snub mount catches bolt, destroys ac belt and vibration damper pulley, stalls engine at crank

 

[neilA4]

The aux belt was close to coming off, was only saved by the bolt head stalling the engine at crank!

 

[neilA4]

More pics. Broken bolt in pivot assembly. Worn rubber bushes in vibration damper and a bit of wear on bush face of damper plate. Going to get a new damper, refurb the bush assembly and clean up bottom mating face.

 

[adamss24]

More pics. Broken bolt in pivot assembly. Worn rubber bushes in vibration damper and a bit of wear on bush face of damper plate. Going to get a new damper, refurb the bush assembly and clean up bottom mating face.View attachment 26852View attachment 26853View attachment 26854View attachment 26855

Don't bother, buy a new cast bracket from TPS, it's about 27 quid trade. Also use a new bush to refurb the assembly ! I would leave the damper alone, never seen one failed and have worked on hundreds...Your call really !

 

[neilA4]

Cheers, have ordered new bushes, bolts washers seals, damper and plate. Got a cheap used crank vibration damper off eBay. Also got new dayco aux belts to go on.