Rear tracking issues

[Nick Jones]

Early '96 4.2 Quattro Sport with signs of an "interesting" life.....

Has wheel alignment issues, which manifest as a pull to the left. After a session on a 4 wheel alignment machine the main issue seems to be rear toe.

4.5mm (!) toe in LH rear and 0.5mm toe out RH rear. This kicks the rear out to the right giving the apparent leftwards pull. Camber is 2º-ve on left and 0.0º on right.

Camber is no problem to adjust and I have a rudimentary gauge that shows I can get that to 0.5º -ve both sides. This will help the toe, but not fully correct it. Road test after the camber adjust shows the pull to be reduced but not gone.

The toe adjustment mechanism (designed by a lunatic presumably) is no longer functioning with the bolt firmly rust welded into the (long) bush sleeve. Mr Grinder will needed to remove it, which will destroy the link (unless the bushes for it are available separately, which I doubt). Deep joy.

Googling the part number on the link 4D0 501 529E (item 23)



mostly throws up a slightly different looking part from the one I have.



which is explained here


Mine is the rare early early version, which is not interchangable, presumably because the vertical link has a tapered hole, and is 4 x the price of the later one. Though I can think of a number of ways around that little wrinkle. Suspect used parts will not be viable. I'll also need to source the inner bolt and eccentric washers, which I'd think are dealer only.

In order to remove the remains I think I'll have to drop the lower wishbone off (to give Mr Grinder access to the bolt head). Both inner bushes look a bit weary also. Not sure if these are available separately? Febi don't list them?

Thought this would be a simple task...... should know better by now. Nothing simple on this car!

Nick

[Nick Jones]

Hi,

Having difficulty finding the eccentric bolts/washers which are items 37 & 22 on the top drawing. If anyone knows the part numbers it would be most helpful!

Thanks

Nick

[Nick Jones]

Had to take the rather desperate measure of actually buying some via the OEM route (TPS)

Bolt 4D0 501 387A (£15.25 - aieee!!) (EDIT wrong P/No, this one is for the camber adjusting bolt, use 4D0 501 387 for tracking bolt)
Washer WHT 001 656 (78p - bargain....) (EDIT wrong P/No, this one is for the camber adjusting bolt, use WHT 001 974 for tracking bolt)
Nut N906 350 01 ( £ 1.32 - not a bargain)

The price for the link arms themselves was £ 171 each + VAT. I didn't buy those.....

Nick

[green A8]

Snap! I'm having exactly the same problem with our old 1996 A8. I'd be interested to know how you got the seized old parts off before fitting the lovely new bits.

[ainarssems]

I am a bit late to the party but I went through the same thing on A6 recently. I already knew that bolts are stuck in the bushes from previous years, on one side bot could be turned just enough in the bush but other side had to be twisted in the bush to get the TOE right last year. This year after both of rear springs broke shortly one after another and rear shocks looked past their best, one heavily corroded and other starting to get moist. I decided to get aftermarket adjustable coilovers front and back as A6 has 190k miles on it and still on original shocks and springs. I thought it would be a good time to replace rear tracking arms and bolts as well.

I got new genuine parts from here: http://www.teile-profis.de/ I did buy tracking arms, bolts, nuts washers and number of other small parts for both A6 and S8 and paid about £160 including the postage for the same stuff that would have cost me £250 in UK. All genuine VW, Audi and Porsche parts, they did offer cheaper alternatives for some parts as well but I went for all OEM parts.

Only bolts that were seized were the bolts used for TOE adjustment so I had to cut them off. I used Dremel with angle attachement and 38mm Speedclick cutting disks to cut them off as there was just not enough space to get angle grinder in there without doing some major dismantling, dropping exhaust etc.
I was very surprised how easy Dremel cut those bolts. Upon dismantling I could see that there has been some serious chemical reaction going on between bolt and bush and produced enough of corrosion material that it had actually cracked the inner metal part of the bushes. Don't know why it happens to this bush as the others were just fine, must be different metal alloy.

[green A8]

Thank you for some very usefull suggestions and tips on where to buy the correct parts from 'Ainarssems'. I'll be visiting that site in the very near future.

I fought a losing battle trying to remove the O/S Lower Track Rods as Audi seem to call them, and that absolute bar stuard of a bolt. In the end I whipped off the roadspring, driveshaft and rear stub axle and lower arm. Almost all of which proved easy, very little corrosion was present on any of the bolts I encountered. Other than the one bolt that remains stubbornly 'in situ'. I now have enough room on the O/S to introduce Mr Bar Stuard bolt to my bestest friend Mr Irate Angle Grinder. Let battle commence!

As you quite rightly stated in your above post, the N/S will be even more difficult to access due to the exhaust location. I'll be buying some cutting discs for the dremel shortly.

My plan is to ditch the tapered type stub axle and buy a second hand pair from this sites sponsors. I suppose it would be rude not to renew at least the rear wheel bearings, and perhaps the splined driveshaft flange, whilst I'm working in the area. Looking at the removed rear driveshaft the rubber boots seem to be past their best so new ones will go on prior to refit. Once this job is done I have no intention of stripping down this part of the car ever again. New springs and shock absorbers (genuine Audi)are also going on.

A couple of things I would like to know. Can you obtain the bushes for the rear lower arm (where the roadspring sits) and the stub axle 3 bushes in total. All of the ones I have look tired,and as stated I'm not going to be stripping this area down again in a hurry (I hope).
Also what grease would you suggest to prevent this major corrosion issue returning to that one stubborn bolt?

I will await replies with interest.

[ainarssems]

See attached file

[green A8]

Thank You very much for posting that link. A phone call to Audi will be on the cards for Monday.

[Nick Jones]

Thanks for that link! Pity I've already bought the bolts (at a rather higher price), but I've filed it for future use. I've also noted that they offer engine mounts for my C4 A6 2.5TDI for about half anyone else I've found. Still a big lump in the context of the car's value though.....

Returning to the A8, it turns out that the part numbers I quoted above are wrong. They are in fact the bolts and washers for the camber adjustment. which are shorter and have smaller diameter washers. Fortunately I noticed before engaging Mr Angry Grinder as TPS (or possibly VAG) were kind enough to miss-pick one of the bolts and accidentally supply one correct bolt, making it obvious something was wrong!

Correct numbers are:
Bolt 4D0 501 387 (just looses the A, no wonder everyone is confused!)
Washer WHT 001 974
Nut N906 350 01 (no change).

The arms (from ebay) haven't turned up yet so I've not developed a removal process yet. I reckon it will be much as suggested above though. Delightful prospect........ Not. Will let you know how I get on (with pics) when I get there.

Nick

[green A8]

I'm sorry to say that removal of this stubborn part could best be described as brutal. It's not one for those frightened of attacking with force!

The angle grinder took care of the O/S arm along with a Bosch powered saw (an electric hacksaw). The Nearside will be next to feel the wrath of these tools joined by as suggested the Dremel. (Once I get some new larger sized cutting discs described above).

In preperation for the attack on the N/S I've had fun removing the exhaust, if only the rest of the job could be so easy. I'm toying with the idea of dropping the rear subframe and getting it cleaned up and painted or perhaps powder coated. The only thing that puts me off powder coating is that corrosion can break out beneath the coating and cause mayhem. Ask any Jaguar owner of a certain age for details of how hidden rot killed their subframes.