Balancer Belts, Bearings and Tensioner

**AlfaJack** · 01-05-08, 11:57

Hi,

Yesterday whilst running in my new front brakes the balance belt tensioner disintegrated, lots all of its ball bearings on to the road and threw the belt off.

So now I am going to purchase a new tensioner bearing and the bearings inside the balancer shaft pulleys (and change the cam belt+ ten etc)
But despite having done a nut and bolt rebuild on one of these engines in the past I can not remember how to get the bearings off the ends of the balancer shaft?

Do I hold the pulleys with grips and undo the bolt with a socket? Are they on a key to the shaft for timing purposes?

I do have a workshop manual I need to re-read but real world advice is always good.

Thanks
Jack

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**AlfaJack** · 01-05-08, 16:36

I think I was confused by looking at the ePer. I do not think there are any bearings in the pulleys of the balancer belt - it would not make sense as it drives the shaft directly.

Any way as I have just posted on other forums, I have just spoken to a 'grale specialist who says that I should be hardly able to notice the lack of a balancer belt.

I certainly could last night, but I realise that when I drove it back the belt was still turning at engine speed and driving the shafts which were probably very much untimed by then due to the demise of the tensioner.

He said they are not really needed. I need to give it a proper run out before I decide to fit new ones or not.

What do you think?

**Steve Webb** · 02-05-08, 06:01

Looks like you had a lucky escape there, its not unknown for balancer belts to take out the cambelt when they let go.

As far as removing the balancer belt, I've heard some people say you can't feel any difference, and some say that it causes alot of vibration. Personally, as your belt seems to have taken itself off, I'd get rid of anything else that is still in there, see if you can live with the extra vibration (if you can feel it) and if you can, just run it without the balancer shafts. After all its one less thing to worry about with the belt removed.

I'm probably going to just replace the cambelt when its next due, and remove the balance belt.

Steve

**Brul(tm)** · 02-05-08, 07:25

Originally Posted by Steve Webb

As far as removing the balancer belt, I've heard some people say you can't feel any difference, and some say that it causes alot of vibration.

The engine reacts a bit different. Some say it runs a bit more agressive, some don't notice the differance. I guess it is different for every enige I suppose. Also if you decide to remove the balancer belts, I think you need to remove the shafts also. There are special caps for sale to close the openings when you removed the balancer shafts.

Greetings,
Marc

**AlfaJack** · 02-05-08, 09:51

Originally Posted by Steve Webb

Looks like you had a lucky escape there, its not unknown for balancer belts to take out the cambelt when they let go.Steve

Yeah I think I was very lucky

Originally Posted by Brul(tm)

The engine reacts a bit different. Some say it runs a bit more agressive, some don't notice the differance. I guess it is different for every enige I suppose.

I will let you know how it runs without it. However I do think the timing has jumped as symptoms are:

Slightly lumpy tick over, sounds okish at the engine end but stand by the back and it sounds quite fluttery and not quite right.

Also it has a lack of low down torque and the turbo is taking a bit longer to boost.

and the engine noise when trying to put the power in is different, its quite boomy now.

Hope to check this out soon.

Originally Posted by Brul(tm)

Also if you decide to remove the balancer belts, I think you need to remove the shafts also. There are special caps for sale to close the openings when you removed the balancer shafts.

That requires engine out and lots of work as I hear you have to cap the other end too otherwise you loose oil pressure. I will leave them be

**Steve Webb** · 04-05-08, 18:05

Yep sounds like your cambelt has jumped a tooth or two. When I had my first cambelt change done, the garage replaced the belt 1 tooth out. The car seemed smoother at first, and had great low down torque, but it had no top end grunt at all. Great for the traffic light GP, (for once) but above 4000rpm there was bugger all power.

I'm not sure about the need to remove the balance shafts, it might be worth while securing them in place so they don't rotate on their own, but so long as they are left in there the oil pathways are going to stay the same. If you do remove them, yes you need to cap them/use inserts to keep the oil pressure up.

Steve

**AlfaJack** · 05-05-08, 11:14

Have now corrected the timing. It was one tooth out on the crank. I reckon yours would have been a tooth out in the other direction as I had less low down torque.

Anyway, it is now driving as expected power wise but I really think it does need a balancer belt as at mid to righ revs it doesnt feel right and its a bit noisier. In no rush to do it as its running well enough for the moment.
The biggest problem I have is that the bottom crank bolt will not budge! Even with our nice big new compressor its not touching it. I think the air hammer might be a bit weak though.

**Evodelta** · 05-05-08, 22:14

The bottom pulley is held on by a left hand threaded bolt so you've probably been tightening it up.

The front balancer shaft will turn because the cambelt idler bearing is connected to it, if running without BSB it needs locking to the nearest unused pulley with a large hose clip.

When changing belts it is simply not enough to just change the belts alone, it MUST be done with ALL the associated bearings too as you have just found out. It is also not very clever to re-tension an old cambelt, it could expire now very easily.

To remove the balancer shaft mounted bearings put a long stout bolt (about 6") in the teeth of the pulley and prop it against something equally as strong to stop it from turning, don't get hold of it with bodge-it grips and mash it up.

**AlfaJack** · 05-05-08, 23:26

Originally Posted by Evodelta

The bottom pulley is held on by a left hand threaded bolt so you've probably been tightening it up.

Are you 100% sure about that? The manual suggests its right hand thread, not by writing but by a little pic showing an anti clockwise direction, and then below another pic showing a clockwise direction with the torque figures next to it

**AlfaJack** · 05-05-08, 23:40

Originally Posted by Evodelta

The front balancer shaft will turn because the cambelt idler bearing is connected to it, if running without BSB it needs locking to the nearest unused pulley with a large hose clip.

Even though the bearings are independent? I reved it to 4K on the spot and there was no hint of movement.

Originally Posted by Evodelta

When changing belts it is simply not enough to just change the belts alone, it MUST be done with ALL the associated bearings too as you have just found out. It is also not very clever to re-tension an old cambelt, it could expire now very easily.

Thats what I asked for (wouldn't consider anything else), seems I may not have got it - should have asked for all the old bits back or at least marked them in some way for proof. They are not our favoured garage these days.
Parts will be ordered this week. Luckily I barely use the car in the week and the belt looks in great condition.

Originally Posted by Evodelta

To remove the balancer shaft mounted bearings put a long stout bolt (about 6") in the teeth of the pulley and prop it against something equally as strong to stop it from turning, don't get hold of it with bodge-it grips and mash it up.

Thanks for the advice. Need I remove them if I am not going to run a balance belt.

And lastly, what are your thoughts and opinions on not running the belt as so far for reasons I do not know it doesnt feel right.

**Juan AR155Q4** · 06-05-08, 02:08

Originally Posted by AlfaJack

Are you 100% sure about that? The manual suggests its right hand thread, not by writing but by a little pic showing an anti clockwise direction, and then below another pic showing a clockwise direction with the torque figures next to it

100% sure is a left hand thread!!!

**AlfaJack** · 06-05-08, 08:27

Originally Posted by Juan AR155Q4

100% sure is a left hand thread!!!

Damn the unclear manual!!! Even the parts guru on the 155 forum said it was a normal right hand thread after looking at the manual!

Bottom left diagram on page 56 of this PDF: http://berlinasportivo.com/Technical...l/Q4engine.pdf - To me it suggests undo turning anti-clockwise and re torque it clockwise.

Ah well, live and learn!

Thanks!

**Evodelta** · 06-05-08, 12:41

Whether it be a circular saw blade or a pulley etc, a centre mounted fixing should always be viewed with caution as to the handing of the thread, they are put on this way so they can't undo themselves....

**AlfaJack** · 06-05-08, 13:11

Originally Posted by Evodelta

Whether it be a circular saw blade or a pulley etc, a centre mounted fixing should always be viewed with caution as to the handing of the thread, they are put on this way so they can't undo themselves....

Yup, agree with that. Just annoyed that the manual is not clear. Our V6s do not have a left handed thread on the crank but my dads Duetto has them on one side for the wheels, now that has troubled some mechanics in the past

**Evodelta** · 06-05-08, 21:10

Originally Posted by AlfaJack

Even though the bearings are independent? I reved it to 4K on the spot and there was no hint of movement.

Thats what I asked for (wouldn't consider anything else), seems I may not have got it - should have asked for all the old bits back or at least marked them in some way for proof. They are not our favoured garage these days.
Parts will be ordered this week. Luckily I barely use the car in the week and the belt looks in great condition.

Thanks for the advice. Need I remove them if I am not going to run a balance belt.

And lastly, what are your thoughts and opinions on not running the belt as so far for reasons I do not know it doesnt feel right.

I think we may be talking about different bearings here perhaps, (a labeled diagram would help maybe?) the cambelt idler bearing is mounted on the balancer shaft so not independant and which is why it can spin it when there is no BB fitted. If it doesn't then maybe your shaft bearings are buggered. It must be spinning if you are feeling imbalance, you wouldn't notice anything otherwise as your engine is sat on floppy rubber bushes.

As to whether to run a BB or not, well my choice is on a road car yes, on a full on comp car engine no, I believe it was put there for a good reason.

**AlfaJack** · 06-05-08, 21:41

Originally Posted by Evodelta

I think we may be talking about different bearings here perhaps, (a labeled diagram would help maybe?) the cambelt idler bearing is mounted on the balancer shaft so not independant and which is why it can spin it when there is no BB fitted. If it doesn't then maybe your shaft bearings are buggered. It must be spinning if you are feeling imbalance, you wouldn't notice anything otherwise as your engine is sat on floppy rubber bushes.

As to whether to run a BB or not, well my choice is on a road car yes, on a full on comp car engine no, I believe it was put there for a good reason.

Cheers. yep that would make it easier.
In the diagram, is number 4 the cam belt idler? and is number 6 the bearing for the BB tensioner (the one that just broke up) ?

If I turn the front balance shaft by hand it feels quite free (same as it did on the engine I rebuilt)

**Evodelta** · 06-05-08, 21:56

Yes they are.

**AlfaJack** · 06-05-08, 21:57

Will get them ordered!

**Evodelta** · 06-05-08, 22:08

And a cambelt, cambelt tensioner too? You might aswell do the whole lot while you are in there, if all the bearings and belts are done at the same time and to the correct tension then you have peace of mind for a while.

**AlfaJack** · 07-05-08, 00:02

Originally Posted by Evodelta

And a cambelt, cambelt tensioner too? You might aswell do the whole lot while you are in there, if all the bearings and belts are done at the same time and to the correct tension then you have peace of mind for a while.

Yes definitely. Looking forward to get it done

**AlfaJack** · 07-05-08, 14:01

All ordered.

?136 delivered from http://www.alternativeautos.co.uk/ or
?130 delivered from http://www.shop4parts.co.uk/ but they didn't have it all in stock.

Part numbers for reference:

Cam Belt: 7774591
Cam Belt Tensioner: 5997325
Balancer Belt: 7614999
Balancer Belt Tensioner Bearing: 7541712
Cam belt Idler Bearing: 5999795

**AlfaJack** · 14-05-08, 21:13

Next problem after the crank bolt which is now out.

I have replaced the bearing inside the balancer belt tensioner wheel with part number 7541712. Then I took the eccentric bit off the block which contains the remains of the old bearing and go to fit it inside the new bearing but it really doesnt look like its going to fit (I know I need to remove the old bearing ball race before final fit

).

The width of the eccentric part is the same as the outer part of the inner metal circle of the bearing (if that makes sense) - i.e its never going to fit inside the bearing.

I believe I have the right part but I am at a loss as to why it will not fit. Have a look at the pics:

Balancer Belt Tensioner Bearing Packaging

Any ideas?

**Juan AR155Q4** · 15-05-08, 14:42

You have the inner part of the old bearing in there.
You have to take it out and get something like this:

**AlfaJack** · 15-05-08, 15:03

Interesting, 2 pieces! I need a better look at it later. I was rushing too much last night to finish up in the garage. I know I have to take that part of the old bearing off but I didnt think it would reveal anything.

Cheers Juan!

**AlfaJack** · 15-05-08, 20:37

Originally Posted by AlfaJack

Interesting, 2 pieces! I need a better look at it later. I was rushing too much last night to finish up in the garage. I know I have to take that part of the old bearing off but I didnt think it would reveal anything.

Cheers Juan!

That is that sorted, thanks again