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Discussion Starter #1
Hello
Over the past few months I've been trying to solve the annoying humming/droning noise from the wheels. I've had bearings looked at, technicians have taken it for test drives all to no avail most times being told its just road noise.:mad:
Then I spotted this post :D
http://www.alfaowner.com/Forum/alfa...rone-from-the-tyres.html?highlight=road+noise
and thought I'd get the wheel geometry looked at to see if it was out and could be causing uneven tyre wear. Turns out the whole lot was out. Kwik fit were able to adjust some of it and sorted the toe settings, but they tell me there is no adjustment to fix the camber or caster. I've taken it to an Alfa specialist with the printout to see if they can sort the rest. Ive attached the measurement diagram showing the before and after adjustments results, red is bad...
Does anyone have any idea what could cause the camber and caster settings to be wrong??

Cheers
Rich
 

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What do you mean by a hum/drone? Only since new, my GT has made a very quiet, slight noise like a cylon from the original series of "Battlestar Galactica" under acceleration, but since I think it sounds kinda cool, I've not bothered to get it looked at.

And yes, I realise that's a rather odd description of a hum.
 

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Discussion Starter #3
hmm don't think mine sounds like a cylon :/ its a hum noise that is quite subdued most of the time but seems to get louder depending on speed and road surface. Occasionly it gets loud enough you can feel it through the steering wheel.
Its this sort of sound, not exactly but similar
http://www.eskimo.com/~bilb/freenrg/taos.wav
This is actually a recoding of a "Taos Hum" an unexplained sound in nature apparently, I've just solved it, its my car :p
 

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Hi Rich,

I had 4 brand new tyres fitted just before xmas and a tracking/geometry done. They rectified the toe in but advised about excessive camber on front ad rear passenger side only. Dealer is currently investigation but it is something they recently noticed on GT's and 159.

Prior to replacing the tyres, I had the same kind of drumming noise as you. This was due to worn tyres (under 1.6mm front wheel and 2.5mm rear wheels) but then Goodyear F1 are know for being noisy when worn !

Would be interested to know how you solved your problem about wrong camber.

Since I have 4 brand new tyres (uniroyal rainsport) the GT us much quieter and suspension much more composed. It's amazing how a few mm of rubber can make a difference :D
 

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That hum isn't like my hum. It's an odd sound mine makes, but the car feels a-ok so I'm not worried.

Could just be a sonic feature of the tyres you have - you don't say which ones they are - although the steering thing is odd. Not lost a balance weight somewhere, have you?
 

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We had a reply by David C on alignment for 147, with further info on the GT. The rear track is adjustable by means of the lower arm inner cam bolts. From memory the camber setting was -35 minutes +or- 20 mins. I would expect to run somewhere between .5 and 1 degree negative. Toe in on the rear .5 degree total about 3mm less at the front of the rim than the back.
The front could be toe out of 0 to .09 degrees, less than .5 mm at the rim.
 

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A friend had this on a merc, turned out to be a puncture repaired tyre on the rear, when repaired the case of the tyre had become locally twisted around the plug, causing the resonance sound at speed and a slight vibration to the wheel but only when this sound appeared.
 

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Strange thing is that your camber settings are slightly high, but the caster settings are too low...
They should be
Front
Camber -0° 39' ± 20'
Caster 3° 55' ± 30'

Rear
Camber -0° 35' ± 20'


Has the car still got the standard springs & dampers?
 

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Discussion Starter #9
Thanks for all the replies people :)
Was in at the dealer/specialist today, gave them the print out for the alignment. Basically they told me the same as kwik fit there are no adjustments for caster and camber, they gave me a printout of specified values(attached), (which to be honest I can't make much sense of) and told me it wasn't anything to be worried about because they were within tolerances
gtachris- thats interesting mine has got the same tyres on the back as when I bought it so I've no idea if they've been repaired so could be something like that, brand new Continental Conti-Sport Contact 2 on the front, same on the back but halfway through their life
David C- the car is completely standard as far as I know.
It doesn't affect handling and is definately not as serious as an unbalanced wheel. Its really just an annoyance but does spoil the enjoyment of anotherwise great car. Having the toe corrected may sort it if it is caused by uneven tyre wear, I'll have to wait and see. Failing that i'll just have to turn the radio up and/or change the rear tyres at some point.

Rich
 

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Thanks Rich - I know what you mean as I have exactly the same with my 147 - droning around 40mph+ on smooth roads. Its only happened since about 3k miles ago. I have Contact Sport's which are almost illegal but I have new new Contact Sports (not 2's) ready to go on soon. I could not trust Kwick Fit ever again though...useless lot.
 

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The tyres on my GT have 9000 Km of life and all four must be replaced due to uneven wear. The dealer told me that this is normal because the tyre is made of hard rubber. The tyre expert told me this is because of the tyre and of the geometry. Has anyone faces the same problem
 

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Discussion Starter #12
doros- Sounds like they've worn very quickly, if the tyres are made of a hard compound you'd expect them to last longer not wear quickly as the dealer says, but at the expense of grip.
You could try getting the car aligned if they are wearing unevenly, though from my experience there isn't much they can adjust anyway, they can only correct toe.

alfa_147_jtd_16v- let us know if the new tyres cure the droning, new front tyres seemed to help a bit on mine but didn't eliminate it, didn't change the rears as they had plenty tread left.
 

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I find this all very interesting. My major complaint about our 147 (apart form shocking ride which must be my age at fault) is the abysmal road noise which seem to come form the rear. I wouldn't characterise it as like hub bearing noise. I've had hub-like noises in the past only for them to disappear completely with fresh tyres, which I put down to either tyre resonance that just happens to sound like hub bearings or an alignment of tyre cavity and hub resonances, one exciting the other.
So far as these alignment measurements are concerned, they are symmetric, that's a good start. I donlt have much faith in results form certain national chains. The last time I went in to one of them all that changed was the steering wheel azimuth - it got drunker!
From the thumbnails you now seem to have negligeable front toein/out, like the spec that's been posted. On the other hand, if I read the diagramme correctly, the spec calls for half a degree of toe-in at the rear while you now have nearly half a degree of toe-out? Your cambers are 'low' in relation to spec (large in negative sense) which could accentuate wear on the inboard side, especially with large tyre sections. So far as Caster is concerned, might not half a degree asymmetry in 3deg just be enough to cause it to pull, and also cause some uneven wear?
Lets be honest, most cars drive round with these sorts of issues, I'm always a little afraid too much discussion can 'talk up' something minor into a lot of worry and big bills. It's worth being doubly sure the toe-ins are within spec and then keep an eye on wear for a few miles. I don't think an Alfa is ever going to be a tranquil ride.
 

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I will in couple of weeks sinnce I am waiting for the new tyres - Good Year ''Excellence'' to arrive to the tyre shop. Thanks
 

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I'm glad I found this thread. My GT sat for 3 weeks then in the first week of driving I noticed a droning/wheel hub noise at about 60mph. Normally below that I can't notice it.

This sounds very similar to what I'm experiencing. However I got new tires on the front two days ago and had the wheel alignment done. I got the same thing about camber adjustment.
 

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I think I get exactly the same but it hums less, when you are going round a left hand bend???:confused: I had 4 new tyres a month ago and had the tracking done then because the inside edge were worn heavily.
 

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All of these geometry problems could probably be explained away by worn bushes, I'd go as far as to say they are caused by the cheap bushings that Alfa fit as standard, Powerflexing the things out should solve the castor and camber, then you can look into the tyre noise, certain brands Goodyear and Dunlop for example are loud.
 
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