D2 Lower Control Arms

[MikkiJayne]

Thats why I made these to ensure the subframe always goes back in the same place:





I haven't actually done a wheel alignment on mine yet so I don't know how the camber is, but its still in the factory location

If you're just doing control arms though, just drop the rear one side at a time and won't move at all since the front bolts will hold it straight.

I am definitely going to have to investigate putting the bolts in backwards

[David's8]

Originally Posted by ainarssems

I though David was only changing straight arms, no cutting and refitting from inside the subframe or dropping subframe is required for bolts if only changing straight arms. .....

Yep. its just the front lower straight arms..... but should i be doing the rears too whilst I am there?

[I am a daisy]

I dropped only the rear mount . I did have to lever the crossmember enough to get the bolt out of rear arm but the crossmember bolt had no problem lining up to go back in. Love those guides MikkiJayne. To get the rear arm bolt in backwards you have to first get it in the opening in the crossmember then use long nose pliers to lift it up and get it in the hole, very fiddly and I wonder how easy it will be to come back out at the next arm change.

[ainarssems]

You would be way out if the bolts did not align, there is a free play in bolts to allow for adjustment. For D2 S8 camber should be -15' to -1°15' on each side so the range is 1 ° or 60' but the difference between 2 sides should be less than 30' or 0.5° so you could have one side -20' and the other side -1°10' and they would both be within spec individually but the difference between both sides would be 50' so way over limit. As little as 1mm movement of subframe sideways can cause you to be out of specification and 2.5mm or more will certainly make it out of spec unless it was wrong before and you were lucky enough to move it right direction to correct it.

[David's8]

Today I put the car into my trusty indy to do the arms obtained from Murrays Direct (as per the link provided by Mikkijayne - no blame attached here!!)). I had checked the Meyle and Audi part numbers against my old pdf parts list and talked with Murrays ref 20" versus 18" differences so thought I was getting the right part. Around midday I got a phone call saying the parts are not right! The old pdf parts catalogue I have stated that for cars to VIN X005501 and between 2000 - 2003 the correct part number was 4B3 407 151C which was what the Ebay seller (Murrays) correctly provided albeit at version "K" (4B3 407 151K) .

However, the tapered pin on the new ones are thinner and the threaded portion longer (see photo). I then checked the actual part number on the cuurently installed arms (not having realised that the number was clearly visible, stamped on the arm!!) it was 4D0 407155N which, according to my parts list, is applicable to vehicles up to VIN X005500.

I had a long talk with Murrays Direct and he (Murray) replied by email "I think the VIN number aspect is a red herring as “X” chassis relates to 1999 model year, and your car is a 2003 model year.
Further investigation reveals that your car appears to have been delivered with or built to the specifications of having 20 inch wheels. See the attached .pdf which details the entire build spec for your actual car, and, in particular, see PR codes “C1S” and “H3Q”.
As you’re aware cars with 20 inch wheels have different suspension components. The part number for the front lower arm is (currently) 4D0407151Q – we have no source for these.
Working on the assumption that the part number from the actual arm is 4D0407151N [rather than 4D0407155N] then we can identify what is fitted – the latest number is 4D0407151P, and this is/was commonly fitted to a vast range of A4’s, A6’s, A8’s, Passat’s etc. and has the larger taper. Why these are fitted to your car we’ve no idea, but strangely they are correct for the “special armoured vehicle” spec!"

I will check out with The Laird (at his leisure) what arms he has fitted with his 20" wheels but if I can see 4D0407155N arms on my car then surely thats what will fit!! Notwithstanding that someone may have removed the 20" wheels AND suspension components in the past.

[David's8]

Photo

[MikkiJayne]

Thats really weird, and also the second time its been mentioned in a week - someone on Audiworld had the same issue.

Do you have steel uprights? For B5 A4 and C5 A6 the large taper is used with steel uprights and the small one with alloy uprights. The 20" hubs have a larger bearing too, but I've never seen them in person. The Brembos on my racecar came from an S8 which I am sure had steel uprights, but the wheels were long gone so I don't know if that was a factory 20" model.

[David's8]

In trying to understand this before ordering more parts, The FACTS are as follows:

1. My 2002 (date of production 06/2002; VIN ending 001316) was originally fitted with 20" wheels and tyres (C1S/H3Q),

2. It is currently fitted with 18" AVUS wheels and the front lower control arm has been verified as 4D0 407155N.

3. The old pdf parts list I use for identifying components/Pt nos states that:
"Arm Assembly Front lower Control
1997-98 4D0 407 151P
1999 TO VIN X005500 4D0 407151P
FM VIN 005501 4B3 407 151C
2000-2003 4B3 407 151C"

So, if I have 4D0 407155Ns currently fitted, would 151s be OK as a replacements. I have not yet checked whether the hubs are steel or not. How is the best way to check this? presumably just a magnet? Are we talking here about the "Steering knuckle"(See attached diagram item 11) to which the control arms are joined or the circular hub (item 2) to which the wheels/brake discs are bolted?

[notorious]

Nice pictures. Is that a brand new subframe?

[MikkiJayne]

Mine? No its just blasted and re-painted.

Originally Posted by David's8

So, if I have 4D0 407155Ns currently fitted, would 151s be OK as a replacements. I have not yet checked whether the hubs are steel or not. How is the best way to check this? presumably just a magnet? Are we talking here about the "Steering knuckle"(See attached diagram item 11) to which the control arms are joined or the circular hub (item 2) to which the wheels/brake discs are bolted?

Number 11. You can usually tell by looking at it - the alloy one is silver, and the steel one is black or rusty.

From pictures, there appears to be no difference between 155 and 151, but its a bit suspicious that the 155 is specific to the D2 whereas the 151 fits pretty much everything else. If they are identical, I'm surprised the aftermarket haven't figured that out. Interestingly the D2 inner bush is a unique number, but the outer bush (for the strut) is shared with loads of other models. Meyle don't differentiate though.

I probably have some 151s in the workshop (from A4s), so happy to send you one to compare to your 155 if you like? If they are geometrically the same we may have just discovered that the D2's 'special' 20" arms are in fact just B5 ones, possibly just with stronger inner bushes