Another Rear subframe refurb...
 

Apologies for the very long post…

Progress

I am well underway with a rear subframe overhaul, and though I would post with some pictures of the progress and a few questions…

It was looking quite rough:

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The process of stripping down has been generally been quite pleasant. The only real issues were some stubborn prop shaft bolts, a diff crossmember bolt seized in the bush (which had to be cut), a seized anti-roll bar drop link end (seized into the hub) and a very stiff n/s hand brake bracket bolt (the one done once the subframe has been lowered slightly).

I refurbished an A4 B5 (2.5 TDI quattro – what a lovely car that was) rear subframe a few years ago, and I seem to remember it being a real pain to dismantle!

I used some pictures from one of MikkiJayne’s old threads as a guide on what to strip off the subframe before lowering, and that worked very well, so thanks for that.

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The subframe looked very crusty, as expected, but after spending a couple of hours with a needle gun it was looking not bad, and actually seems very solid. The eccentric bolts guides (? – the raised bits that hold them in place) were all in great nick, unlike the ones it the A4 one I did (which had mostly rusted away!). Maybe this car hasn’t spent all it life in Scotland!

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I will give it a bit more of a clean, and then probably paint it (I have ordered some Rust-Oleum as per MikkiJayne’s recommendations that I have seen). I might look into getting it blasted and powder coated, but am not sure if this will be worth the extra cost? This may also depend on the subframe bushes…

Other stripped parts:

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Parts

Which leads me onto the then next bit, getting the replacement parts. The previous posts on this forum have been a great help, and I (think I) have got far more of the bits than I though I would through Auto-Doc, but would be happy for anybody to point out anything I have got wrong (or could get better elsewhere – the order has been placed, but I can always send back)!

Wheel Bearing Housings
4x FEBEST VWAB-039 (bonded rubber bush 4D0 505 171 L)

Trapezium Link / Axle Guide (lower)
4x Febi Bilstein 32226 (mounting 4D0 505 171 H) – I understand these are steel rather than aluminium
2x MEYLE 100 511 0007 (mounting 4D0 511 523 C)

Transverse Link / Wishbone (upper)
4x FEBEST ADAB-022 (bonded rubber bush 4D0 505 203 E)

Anti-Roll Bar
2x FEBEST ADSB-4FHR (mounting 4D0 511 327 C)
2x MEYLE 116 060 8240/HD (coupling rod 4D0 505 465 D)

Miscellaneous
2x MEYLE 116 050 0164 (Track Rods 4D0 501 529 H )
2x FEBEST 2329-006 (Eccentric Bolt 4D0 501 387 A - these were probably fine, but for the cost I thought just get new)
2x FEBEST 2329-007 (Eccentric Bolt 4D0 501 387 B - these were a bit rusty though might have cleaned up okay, but again for the cost I thought just get new)
1x FEBI BILSTEIN 25282 (Coupling Rod (left) 4D0 505 547 C)
1x FEBI BILSTEIN 25280 (Coupling Rod (right) 4D0 505 548 C)


Missing Bits:

The items that I have not been able to get (so far) are:
4x subframe bushes, which I understand can be the D3 bushes - Lemforder 27312 01; these are out of stock everywhere (though I have not tried the local Audi dealer yet)

2x bonded rubber bush 4D0 505 203 G - from the middle of the upper links/wishbones; this does not seem to be available anywhere (I was actually surprised to see the other 4 bushes on the links were available, as I though I read none of these were available)

2x lower spring support 4D0 512 297 E - these are really rusty so it would be good to replace, but – as expected - this does not seem to be available anywhere; I might just look out for some reasonable second-hand ones, if such things exist!

2x upper spring support 4D0 512 297 G – again I did not expect these to be available, and they actually look fine so I do not think this will matter.

1x gearbox support bonded rubber bush 4D0 599 381 E, which I understand can be replaced with the D3 version - 8E0 599 381 B; these are out of stock everywhere (though again, I have not tried the local Audi dealer yet)

I also need to replace the diff crossmember support rubber bushes (especially as there is still part of a bolt in one of them!), and have sent a pm to MikkiJayne to see if she can do the refurb (as she mentioned she might be able to start doing in a previous post).

Shocks & Springs

So what does that leave? Well, shocks and springs…

The springs seem pretty good, though quite rusty at the very bottom. I think the shocks might be done though, however to be honest I don’t really have enough experience of testing them to be sure, as I am not sure how stiff they should be.

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I have attached a video of me pushing and pulling them, which is easy enough with a couple of fingers – I would have assumed it would be harder than this?

If they do need replaced then the question is with what. The one thing I do not want to do is lower the car, and I don’t want it to be particularly stiffer – mainly because I live a long a track. I guess I could get some decent 2nd hand ones from the forum sponsors, or go for something like the Bilstein B6s (if these work with the standard springs; or even the full B12 kit if not, or if this would be a good thing to do anyway), as long as these don’t lower it etc. Or is there any other recommendation?

Subframe

As noted above, I have not been able to get the subframe bushes yet, but like the shocks, I am not to sure to tell how worn out these are. I have attached another video showing how much (what is probably) the worst one moves. Does this look bad good? If they do need replaced then hopefully I can get them somewhere, and I might look more seriously at blasting/powder coating too.

Tools

And the last thing for now, with regard to installing all the new bushes. I have access to a 10ton press, but I have seen some comments about using the right tools (assuming big sockets sets won’t do the job!). Would anybody be able to rent these out for a reasonable fee and postage costs?


Thanks for reading this far and I look forward to any comments and feedback, good or bad!

Scott

I managed to get a set of 4 D3 bushes for £60 from poland, they now appear to be sold out everywhere.


You can be the first one to try the poly subframe bushes if you want:

https://poliuretany.olkusz.pl/pl/aud...lnej-1szt.html

they also have all the other bushes you are missing in poly version, no one has tested them though

Thanks, that looks interesting. A bit more research led me to an older thread of yours with more useful stuff about them - http://forum.a8parts.co.uk/showthread.php?t=15680

I will probably look at the front subframe after this, so it might be worth getting a full set for both subframes to match. Fortunately I replaced all the rest of the front suspension (except the shocks) about 7000 miles ago, so I hopefully won’t need too many more parts for that…!

If I was to get the poly bush for the front diff mount, do you think it would it be better to get the rear bushes too to match?

https://poliuretany.olkusz.pl/pl/p/P...1szt./23111969
https://poliuretany.olkusz.pl/pl/p/T...2szt./23111307

Look like it will be about £80 including delivery for the full set, and likely some import charges to get it into the uk.

I think I will avoid using poly on the wishbones though, so I will have to keep looking for 4D0 505 203 G from the upper wishbone, or just leave it in place.

the last 2 of febest ADAB-021 or 4D0 505 203 G have sold on ebay in australia. Febest was the OEM for audi on this and after emailing them they said it won't be back in stock 'for a while' however long that means.

Usually those 2 bushes are fine and don't need changing, I've witnessed this yesterday when I removed the whole rear suspension with another forum member.

If i was you I would also get the 4 camber bolts from autodoc as they are cheap and still available, the part numbers are somewhere in on of the threads too

Given the lack of the main subframe bushes, I'd suggest sandblasting the subframe and painting it which is what I do with the fronts.

The OE shocks seem to last pretty well, and tbh there isn't really much in the way of alternatives. The Bilstein B6s should work with stock springs, although they are quite stiff. The B12 kit doesn't lower an S8 at all. It rides quite firmly but is acceptable on 20s, but is pretty expensive.

I made tools to push the bushes in from the outer flanges which works fine on the OE parts and the B5 steel ones, but the metal on the Febi alloy ones is so thin the flange isn't strong enough. For those I just had to push them in on the mounting face, which did work ok. Doing it like that needs a sleeve on the opposite side as the second bush has to go over-centre to get it to seat, which pushes the first one out slightly. I've not seen the Febest ones though so I don't know how they would behave. I'm not going to buy any more of the Febi versions.

Thanks Ronin, I have the camber bolts already on order (I saw your old post about them) – as you say, they are not very expensive.

And thanks MikkiJayne; with regard to the subframe, are you saying you would probably just keep the bushes as they are and save on the £200 odd for the poly bushes and hassle of removing them? That sounds like a good option to me if so! The existing bushes do not seem particularly bad. For reference, the car has 123K on it…

You note the Bilsteins ride okay on 20s – would they likely be okay on 18s too? I have a set of both, but haven’t really used the 20s yet (they have terrible tyres on them, and I have not got round to replacing them yet; I put good tyres on the 18s after getting them refurbed, and they also feel a bit safer with the potholed roads up here!).

That would just leaves the diff bushes. It looks like I have three options:

1. Get you to do the rear bushes and just keep the existing front bush (do they tend to go?; it has a fair bit of movement when you leaver it with a big screwdriver – I could post a video?)
2. Get you to do the rear bushes and get a poly bush for the front.
3. Get the poly bushes for the front and rear.

What would you be likely to do (not worrying about any cost differences)…?!

It looks like fitting the bushes will be a bit of an experiment then. I have done plenty of that before, so will report back!

Scott

I've been leaving the upper arm bushes alone. I dislike poly in suspension arms as it sucks at both ride comfort and longevity -I'd rather have used OE in this application than poly, until we can find an alternative source.

My experience of Bilsteins with 18s is that they are are very bouncy - think of an F1 car where the tyre does 90% of the suspension travel. This is, I'm sure, partially down to my Goodyear tyres which have very soft sidewalls, and so 20s make the suspension work better than 18s, but I've had B12 kits on a couple of other cars and they are always very firm. If you're running on 18s tbh I'd stick with the stock suspension. Big Red has 150k on stock suspension and rides and handles great.

Diff bushes you could do with poly as the joints aren't static, rather than rotating. It'll transmit more vibration and noise in to the subframe, which with stock subframe bushes will probably be unnoticeable. With poly subframe bushes though it may increase nvh in the cabin. I'd be inclined to only do one set. Personally I would do the D3 bushes on the diff and poly on the subframe, given the limited available options. The D3 front diff bush should still be available from TPS - I don't think it is expensive. I can check today.

WD40 is the secret sauce for getting all these bushes to go in by the way. It stops them galling up on the aluminium castings.

With the subframe out it's also a good idea to do the fuel tank straps

Mikki - That is very helpful information about the Bilsteins / 18s; that could have been an expensive mistake! I am happy to keep the existing shocks (especially as I am not really looking to stiffen up the car or anything), but was just a little concerned that they were a bit worn (what did you think of the video clip?). To be fair though, other than the terrible creaking from the rear, the car felt absolutely fine handling wise. Hopefully I can just give them a paint and be done!

I called my local TPS today for the first time and it turns out they sell to the public, so that is handy, however they don’t think they will be able to get the diff bush. I also spoke with the local Audi dealer, and they say they can get it from Germany, and will be about £30ish.

If you can get it from TPS though I could just send you both the housing and you could fit all three?

Ronin – I was looking a those, and the hose clamps to… they all look very crusty. Working on old cars is always like opening a can of worms… It would be mad not to do them at this point though. I have not looked at what the process for this will be yet – is it a tricky job…?

The following PDF gives details on the removal of the fuel tank. Not sure if it's possible to just replace the straps one by one with everything still in situ:

http://forum.a8parts.co.uk/attachmen...8&d=1420350463