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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  
Old 5th June 2015, 12:33 PM
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Goran Goran is offline
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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
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  #12  
Old 5th June 2015, 01:08 PM
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Quote:
Originally Posted by The_Laird View Post
I've also read that warping a disc is a pretty unlikely event - just how hot would they have to get to warp that much metal anyway?

I had a long running battle with this too and, whilst I agree that bushes are a likely candidate for the cause of the problem if it's shuddering when you're not braking, other factors may be in play, as David suggests.

My problem started after I'd had new discs, refurbished calipers and new pads. It was great for 2-3K miles, then the shuddering started and got worse. New discs and pads under warranty cured it, but the same happened again after 2-3K miles. And again!

The cure was to get the discs skimmed in situ. They weren't warped, just not quite in line for whatever reason. And it was confounded by a rear caliper seizing a little. Been fine now for at least 15K miles.
That's generally my experience too; great at first, then 2-3K miles later ...

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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  #13  
Old 9th June 2015, 02:59 PM
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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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  #14  
Old 9th June 2015, 11:57 PM
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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  
Old 13th August 2015, 10:22 AM
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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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  #16  
Old 13th August 2015, 10:50 AM
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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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Last edited by Cornershop; 13th August 2015 at 07:56 PM.
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  #17  
Old 21st May 2017, 10:11 PM
Mossyboy1978 Mossyboy1978 is offline
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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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  #18  
Old 12th September 2017, 08:24 AM
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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.
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  #19  
Old 12th September 2017, 09:07 AM
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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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  #20  
Old 12th September 2017, 01:55 PM
Tomson Tomson is offline
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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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