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D2 - Axles, Brakes, Suspension and Steering Brakes, Springs, shocks, steering racks, steering columns, suspension arms, wheel hubs etc. |
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#11
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Have a read of this. If it is the discs/pads its likely to be uneven pad material transfer to disc. You would have to get the discs skimmed and use new pads.
Does this happen due to breaking style or due to poor quality pads? I have no idea. http://www.stoptech.com/technical-su...nd-other-myths |
#12
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Quote:
I guess once they've bedded in, and friction improves, any minute difference in rotational disc-to-pad distance becomes noticeable. In fact, I had new Brembo discs and pads fitted all round just a few thousand miles ago, and they've just started juddering a little. And since I had just about every arm, link and bush replaced on the front suspension around the same time, I can pretty much rule out any other cause. I think skimming discs in situ is the only way to ensure the disc spins true and isn't affected by hub/mounting imperfections. I plan to get my discs skimmed in the next few weeks.
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Mark ------------------------------------------------------ 2002 FE S8 Ebony Black Pearl ------------------------------------------------------ ------------------------------------------------------ Cars Owned: The Tesla Era: 2020 Model S Performance Ludicrous+ (present) (Black, with all black premium interior and carbon fibre décor, 21" sonic carbon twin turbine wheels and FSD capability) The Audi Era: '97 A8 4.2 (Ming Blue) --> '96 A8 4.2 QS (Dark Green) --> '02 FE S8 (present) The Citroen Era: '84 BX 1.6 RS --> '89 BX 1.9 DTR Turbo --> '94 XM 2.0L Turbo --> '96 XM 2.0L Turbo Exclusive --> '00 Xantia Activa 2.0L Turbo The Banger Era: '76 1.2L Lada VAZ-2101 (Ruski Fiat 124) --> '80 1.7L Morris Ital HL, finished in Ermine White and Rust |
#13
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Discs are being replaced by F1 tomorrow so fingers crossed the rumble stops after they are bedded in. I assume the almost new pads which they replaced will be OK with the brand new discs.
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Currently '8-less Previously: - Aqua Blue Pearl D3 S8 - Kamut Beige leather, ACC, B&O, factory RSE, solar sunroof, electric blinds, ski bag, Homelink, comfort headrests. - Aqua Blue D2 S8 - Grey leather/Alcantara - D3 A8 3.0 CVT - D3 3.7 V8 |
#14
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I'll put good money on this being worn suspension bushes, not the brakes at all
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#15
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Well, I think I'm getting to the bottom of it. After the recent Audi health check (here) indicated that all suspension bushes were worn, I've had them replaced all round.
A trustworthy garage I know first replaced them with third party parts and the rumbling under braking was still there (warped discs sensation). They then got in contact with a VW master tech who announced something I've never heard of before and would be staggered if it's true... I've recently fitted the bigger 20" Cantona wheels from a D3. This tech believes that D2s which came from the factory with 20" wheels (FE cars, for example) had uprated and meatier lower arms in the suspension to accept the extra load. The lower arms which the garage fitted yesterday were rubbing on the hub at one of the ball ends so it's back today to be fitted all round with Audi OE arms this time. If this doesn't cure it then it must be an issue with either the hub or brake discs not properly aligned, surely?
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Currently '8-less Previously: - Aqua Blue Pearl D3 S8 - Kamut Beige leather, ACC, B&O, factory RSE, solar sunroof, electric blinds, ski bag, Homelink, comfort headrests. - Aqua Blue D2 S8 - Grey leather/Alcantara - D3 A8 3.0 CVT - D3 3.7 V8 |
#16
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Factory supplied cars with 20" wheels defintely had beefier wheels bearings than 18" wheel cars, as i've just gone through this and was asked by the supplier whether i had 18 or 20" wheels.
Wouldn't surprise me if other components were also diferent ETA : link here to allgerman parts, you can see first set of arms are for 20" wheels (not brakes!), the last set are "not for rim size 20" " http://www.allgermanparts.co.uk/defa...m-571.html?p=4
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Shirish: 2001 S8 Last edited by Cornershop; 13th August 2015 at 06:56 PM. |
#17
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I had a similar problem - judder at about 70 mph and nasty when off the brakes, severe when on them.
Turned out to be a buggered front caliper. One of the dust seals around the pistons had failed and corrosion had set in, leaving that single piston slightly jutting out. No problem at low speeds but as the car got faster and the binding piston heated up, things got tighter and worse. Caliper refurb has sorted it. Mossy
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2002 S8 Aqua Pearl, entirely original apart from FE 20" OEM wheels and Milltek exhaust. |
#18
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I am just dealing with this now, it seems to be one of the many features of these wonderful beasts.
Worn out arms were an advisory at the least MOT, so have just had these replaced - no real difference, if anything it has made it worse as less play now. I have just purchased 4 new tyres from Tyres365 so will see if it makes difference with new tyres and balanced wheels. This is my next cure as the car had no brake wobble on a trip to Le Mans with different wheels and tyres on, and the current tyres are badly worn budgets (Triangles!). Also the standard 20's were refurbished by a local bodyshop last year, so who knows how many weights remain! I have gone for Vredestein ULTRAC VORTI's which seems to get great reviews and were only £136 per tyre. Will report back with whether this fixes the issue or whether brake calliper/disc/pad investigation is required. |
#19
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If it's too many/not enough wheel weights fitted then the wobble will be constant and not just under braking.
Have you tried skimming the discs? That's the only thing I didn't try with mine and I'm convinced it would have solved this.
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Currently '8-less Previously: - Aqua Blue Pearl D3 S8 - Kamut Beige leather, ACC, B&O, factory RSE, solar sunroof, electric blinds, ski bag, Homelink, comfort headrests. - Aqua Blue D2 S8 - Grey leather/Alcantara - D3 A8 3.0 CVT - D3 3.7 V8 |
#20
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Discs are fairly worn, so will try replacing them after messing with the tyres.
I'll report back. Tom |
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