Technical Stilo 1.9 loud tapping or clacking from aux belt area

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Technical Stilo 1.9 loud tapping or clacking from aux belt area

Thanks abarth, what makes you think the pulley has started collapsing ?

So far the only indication I have that the belt is too tight is that it seems to have stretched by 1cm. Which might be normal?
 
Hi

For the pulley to move so eratic it can be 3 things:
• loose as Ralf has suggested or
• collapsed rubber between bottom and outer of pulley or
• since there are no load or stabilizing force from a belt maybe it should move like this?

I suspect since it worked fine for a while and now there is noises, it indicates that maybe due to belt being too tight or misalignment the Crank pulley has now got damaged I suspect.
On condition 4 bolts were tight.
 
The pulley still looks odd to me.. but seems to be the "normal" layout with the 4 bolts holding it to the crankshaft. Maybe it's just how Gates build them.

Mine (55096301) looks slightly different as in the picture... but the only other pulley for a JTD is 55190424 (which looks more like yours) but the Gates TVD1013 is the replacement for both types, so I don't know what the actual difference is.


Is your motor a 16V? That has an aux belt that should be 1360mm, even though the pulley is the same 55096301. The 8v's (even the 85bhp) had the 55096301 pulley and a 1270mm belt, when A/C was fitted.


You'll probably need a new pulley (avoid Gates this time, although they usually make good components). Try to get one that looks like the picture, without the cover plate, since it could be that which is making the clattering noise.

But also check the tensioner. There's only going to be one way to test it and that's to compare it to a new one, so that's the next thing to buy. If your pulley is quiet with a new tensioner, then Robert is your mother's brother.. but otherwise a new pulley ought to finally sort it.


Ralf S.
 

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Thanks guys.
Ralph yes the gates one I bought last year is a different design to the original. I pulled out the old to show in pic below. It was propa shagged.

The gates one I bought last year seems to be a bit odd on further inspection. The second outer rubber (which is not visible) seems to be off centre, when I pull hard bracing it in my hand it’s comes back to an off centre position. I checked the motor running without it one, the shaft itself spins nice and cantered.

So it looks like either this gates pulley is, yet again, failing too quickly. Or I’ve done something wrong. I mean last year after only 2 weeks a previous pulley failed, then the replacement (warranty) worked for over a year to now. I’m thinking I’ll find an original Stilo pulley from a broken car at this point. One that looks exactly like mine. I know it might not run that long (though these are surely good for big mileage) but it’ll at least be a sure test.

If my tensioner is too loose I don’t see how it can wreck the pulley. And I just don’t see anything that has made the belt tighter. When it’s all assembled I can just about live the tensioner when pulling down on the top stretch of the belt (between alt and water pump).

99149494-2d4b-46ed-8a03-ae5a7c8cd419.jpg
 
Just for curiosity.

Are the OD the same on Original vs Gates?

If Gates has a bigger curcomfrence then the tention will also be higher.
Although unlikely it will differ.
 
The main difference is the other side. The outer rubber is tough and leaves a spring gap enough to resist the clacking I’m getting on the gates one. I’m really surprised by this difference since the force from the belt is obviously not centred and will force the pulley constantly in a non symmetrical spin.

I’ll take more pictures. I might even contact gates to see if they’ve had recalls.
 
Some vehicle manufacturers specifically warn running the engine without the aux belt fitted will ruin the tvd very quickly.
Jack
 
You may wish to check large crank bolt holding crank sprocket hasn't worked loose.

The torque spec for the four small bolts retaining the tvd is quite low.

Has someone in the past over tightened these bolts damaging the threads in the crank sprocket?
 
Thanks guys.
Ralph yes the gates one I bought last year is a different design to the original. I pulled out the old to show in pic below. It was propa shagged.

The gates one I bought last year seems to be a bit odd on further inspection. The second outer rubber (which is not visible) seems to be off centre, when I pull hard bracing it in my hand it’s comes back to an off centre position. I checked the motor running without it one, the shaft itself spins nice and cantered.

So it looks like either this gates pulley is, yet again, failing too quickly. Or I’ve done something wrong. I mean last year after only 2 weeks a previous pulley failed, then the replacement (warranty) worked for over a year to now. I’m thinking I’ll find an original Stilo pulley from a broken car at this point. One that looks exactly like mine. I know it might not run that long (though these are surely good for big mileage) but it’ll at least be a sure test.

If my tensioner is too loose I don’t see how it can wreck the pulley. And I just don’t see anything that has made the belt tighter. When it’s all assembled I can just about live the tensioner when pulling down on the top stretch of the belt (between alt and water pump).

View attachment 211760

It's an odd problem for sure... but new pieces might help to work out what's gone awry.

My Fiat pulley has 205,000 miles on it, and shows no signs of disintegration at all (it lives in Wales though, so it's very rarely warm, never mind hot)… but it means the Fiat pulley is pretty sorted. A second-hand Fiat one will be cheaper than a new one, at least until we work out what's killing the pulleys, if anything. It could just be that the Gates pulleys are not great and there's nothing wrong with the car itself.

The Gates pulley must be the same size as the Fiat one, since the 55096301 pulley uses a 1270mm belt and the 55190424 pulley (16v) uses a 1360mm belt.. but the Gates TVD1013 pulley is listed as replacement for both of these Fiat ones. I suspect the 16v may just have a different pulley-locating arrangement since the crank will be different.. and the Gates pulley can fit on either the 8v or the 16v by being made more "universal". It could be as minor as that.

Don't worry about your 1275mm belt. When I measured mine I think it was also 5mm longer. It could be the belt is measured on the inside run, whereas you and I probably measured around the outside. Anyway, 5mm is so trivial that it makes no difference.

I don't see how the tensioner can be wrecking the belt either... it has a spring that presses against the belt.. so there's a finite amount of force it can exert... but it could be "uneven" if it's a bit sticky, so that the pulley experiences "tight" then "loose" as it goes round. Admittedly it's a long shot.. :D

Can you rotate the tensioner all the way to the end of it's travel? I had to buy an extra-long (40cm) 15mm ring spanner to be able to get enough leverage on the tensioner (I'm sure it'd be easier if the car was on a ramp) but now I can rotate the tensioner right round to it's end stop. With no pressure on the belt at all, the belt will fit easily over the other pulleys.. but there's not much belt to spare.

If your tensioner moves freely and without graunching/grinding or any indication that it's stiff or sticking ("heavy" is okay.. ) then cancel my suggestion to change it. I talked myself out of it.

I doubt your belt is twisting the pulley. If it was misaligned, you would have wear on the shoulder of the belt. You would see the grey/brown cords being exposed, instead of the rubber shoulder.

Can you photograph your aux belt run? I wonder if it's fitted right. It should pass ribbed side onto the grooved/metal pulleys and smooth side to the smooth/plastic pulleys. I can't remember if it will fit in any way except the right way, if you obey that ^ rule.. but it might be possible. That could be making the belt too tight..?

Otherwise, if it all checks out, then I'd have to conclude that there's nothing wrong.. just the pulleys (both Gates) both failed. The Fiat (or any other brand) might fare better.


Ralf S.
 
Hey Ralph, hey lads,

Right I managed to get another pulley in a rush from a breakers. The idea was to get an original Fiat part but the damn thing was a Bayko with same build as my Gates. I really don't want to throw too much money at this since I still don't bloody know what the cause is.

I'm going to hunt around for an original Fiat part that's in good nick. They're easy to check, just squeeze the inner ring outward to the outer ring and see if you can hear metal grinding (the current effect of by bust Gates pulley) which becomes the clacking or tapping sound once mounted (since tension on the pulley is only from the bottom and as Ralph says it's tight then loose then tight then...etc.)

The only lingering doubts i have is how the hell can Gates make parts that fail so easily (these cover Alpha JTDs too I think). Also, what if the lack of tension (which I don't think is true in my case) meant that spin is too loose and causes the pulley so wear out from off center spining. Which goes with what jackwhoo had read. If it's true it's totally unacceptable to produce parts that have no range of allowed tension. I mean my belt is 1 year old, it doesn't slip, the tension is good ....

Anyway lets see what this new pulley spins like. Will update. Hopefully this post will help others in the future.

One thing I can't find that would help, anyone have a diagram of the whole setup so I can check the positions of each part - JTD 2002 1.9 115hp ?
 
Not sure what setup diagram you want. Any of this any use?
.
 

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Thanks Davren. Yes that helps. The last one especially. Though mine is not a v8, it’s the same setup bar the top pulley.

I’ve put the Dayko pulley in now. It seems ok. Let’s see how long it holds. I did another video in the name of science (below). You can hear a short hissing on the spin and then it settles after a second.

The main question now is: are you other JTD guys seeing the same slight wobble on your cars as in the video below. I mean it could be totally normal and due to the off centre force applied to the pulley acting on the rubbers. The outer ring especially seems to wobble a bit. I’ve got no odd noises though, from the belt.
I’ve also added a picture of the three pulleys I have. You can see the original one took a lot of punishment before going. It’s outer rubber looks way tougher and lore convincing the man the Gates (#2) and Dayco (#3) ones.

https://youtu.be/ucsSCImbxmw

View attachment 211822View attachment 211823
 
I'm not sure if it's a slight wobble, or if it's just an optical illusion caused by the pulley colouring. But it looks like mine does (apart from my pulley is a different type).

If you're really worried about wobble, you can check the run-out by holding something against the metal rim of the pulley to see how much it floats... but the number of things that can go horribly wrong Ahhhh Ahhhh are legion, so use something long, support it against something that doesn't move, like the suspension strut, and make sure it's soft/bendy so if it gets sucked into the belt, it won't cause damage. A drinking straw or a lolly stick would be better than a screwdriver.

But there should be minimal run-out since the other pulleys should all line up with the crank pulley. The main ones to compare are the a/c and the alternator pulleys, since they're grooved and hold the belt in position, whereas the smooth pulley have no lip to hold the belt in place, so it can wander left or right to help itself stay straight. Since the belt is straight, it shouldn't be putting any major sideways pressure on the pulley - the rubber is to prevent "shunt", rather than to allow the pulley to flex.

Hopefully that pulley will last okay now. If I can get round to it (I have the horn to fix) I'll video mine so you can see what that does... but that'll be weekend after next probably.


Ralf S.
 
Ralph thanks very much for your input.

Over a week now since they’ pulley is in and it seems to be fine.

Time will tell!

Thanks again
 
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