[bmw_solid]

Hi All,

Just replaced the vibration damper pulley and also changed the tensioner pulley with it as the belt was sitting around 7mm off the pulley!

With both the old and new tensioner pulleys, why have they designed it so that you have to turn the central pulley torx bolt anti-clockwise to make the tensioner go down and loosen the belt? Every time I did that, the bolt kept loosening and I had to keep tightening it and after a couple of trys I eventually got the tensioner down enough to get the belt off / on again.

The new one was worse than the old one - to get the belt on I barely got it on the alternator pulley as the bolt would loosen if I applied more force. After it was marginally on the alt. pulley, I had to rotate the engine manually to guide the belt into place!!!

If I tightened the tensioner pulley bolt clockwise then the tensioner sprig would not move, obviously. Surely something is wrong here??

What is the torque value for the tensioner pulley torx bolt out of curiosity??

[maryjane]

The pulley is through bolted to the arm...IF it gets slightly loose youll have a very hard time getting the arm to rotate fully to allow easy belt swaps. IF you have a sacrificial 15mm wrench you could cut down you MIGHT be able to tighten it IN the car, just remember that its REVERSE threaded. Hope this makes sense and helps.

[bmw_solid]

Originally Posted by maryjane

The pulley is through bolted to the arm...IF it gets slightly loose youll have a very hard time getting the arm to rotate fully to allow easy belt swaps. IF you have a sacrificial 15mm wrench you could cut down you MIGHT be able to tighten it IN the car, just remember that its REVERSE threaded. Hope this makes sense and helps.

Hi, not sure what you mean by through bolted to the arm... Also its not reverse threaded because to tighten the bolt it has to be turned clockwise and anti for loosenint which is the direction I have to turn in to bring the tensioner down.

According to some Bmw procedures I've seen on the net it says insert a torx fitting (attached to a breaker bar) into the torx bolt and push down on the bar to move the tensioner pulley down! Not sure how pratical this will be with a torx fitting in terms of slipping etc.

[maryjane]

This? That REAR bolt is a 15mm it is reverse threaded, you'd need to either remove the entire assembly to tighten it OR cut down a 15mm wrench to be able to grab it from behind IN place on the car.

[bmw_solid]

Originally Posted by maryjane

This? That REAR bolt is a 15mm it is reverse threaded, you'd need to either remove the entire assembly to tighten it OR cut down a 15mm wrench to be able to grab it from behind IN place on the car.

So the tensioner pulley on my car doesn't have a hex head bolt - it has a T50 torx bolt instead. Only way to remove tension from the belt is to turn the torx bolt anti clockwise or according to some sources, push down on the torx bolt instead of turning it which in turn pushes the tensioner down.