Part 2 : Now I’ve removed the bushes, and replaced one, I suppose I’d better getting on with replacing this busted transverse arm.
As you may recall from part 1, I am having to do extra I put the new bushes in, to take the old broken transverse arm out, and replace it with a new one.
Right: You can clearly see the end of the transverse link arm is bent out to the right more than the left. Note: I’ve not put the replacement bush in at the top yet.
You can also see that this appears to go a long way “in” to the centre of the car, and puts things like the suspension spring, drive shaft, and ARB/droplink into perspective.
So – getting it out is easier said than done.
Firstly, getting the bolt out of the sub-frame end of the transverse arm was difficult. Despite all the normal precautions of liberally sprayingWD40 on the nut, and brushing as much rusty crap off the end threads as possible, the nut jammed onto the bolt as I was unscrewing it.
Right: This is how little the nut came off the bolt – maybe 4 or 5 mm – but thankfully just about enough to be able to get a hacksaw between the nut and the rear subframe.
Going to be cutting rather close the subframe mind ! Oh well – this is the sort of challenge that makes life fun eh ? 🙂
A somewhat further away shot (Right:) shows rather clearly that nice little gap between nut and subframe, but again just how far *into* the car this is.
This also shows now much of a pain in the arse this is being the top transverse link instead of the bottom one.
The black circular thing on the left is the drive shaft from the rear diff to the wheel hub.
Nothing to do but to get the trusty hacksaw out, and start hacking away at a 10.9 bolt – not exactly hot knife and butter time.
Right and below: So up steps Mr H. acksaw and after giving me a sore arm and shoulder some time later, as well as “excuse” to blurt out a few choice words during – the bolt 
is cut to release the seized on nut, and I can start think about removing the bolt from the transverse arm and subframe.
You would have thought that the problem 
ends there right ?
No.
As you can see from the shot to the right, the top transverse arm bolt looks awfully close to the subframe to chassis bolt, and it could be down to luck and a following wind that allows the transverse link nut to be removed without doing anything to the subframe nut….
….. but no luck or following wind today ……
In their infinite wisdom, Audi appear to have built this thing such that one of the bolts that holds the subframe to the chassis does actually foul the path of the bolt holding the top transverse link to the subframe – ARRRRGGGGGH.
Right: Nut fouling. No, nothing like that ! Sorry – bit of sense of humour failure today . :-s
Guess what – the bolt that holds the subframe to the chassis is a stretch bolt that needs replacing when it is removed !
OK – it’s a dead cheap part all things considered, but it’s one thing I wasn’t counting on, and once I ‘d taken out the transverse link bolt, and ultimately replaced the arm, and put it’s new bolt it, I put the old subframe -> chassis bolt back in overnight, until I could get hold of the new bolt (note, I wasn’t driving the car, so it didn’t matter)
There is an awful lot of commentary on the Interweb about stretch bolts, and whether or not to automatically replace them as per the instructions in a workshop manual once you have undone and removed them.
Frankly, for the £4 or so that it costs to replace them, the peace of mind I have (and so should you) of following the replacement as documented in the manual is well worth it – there are very good reasons why you should replace them, which I won’t go into – JFDI – Just Fucking Do It.
Replacement is pretty much reverse of dismantling it, just remember to torque everything up accordingly – noting that as these are rubber components, the final torque and turn must be done with the weight of the car fully on the suspension – which is “entertaining” without a full car lift or a pit.
Right: Transverse link replaced, and looking for line up of the holes before threading the new bolt through.
Other than the challenge of the subframe mounting nut, and the hacksaw, replacing the arm wasn’t really difficult, as with all these things, slowly and carefully work through each and every step, and you will be rewarded.
Whilst we are here, we should take a moment to look at what I’ve replaced, and why…
Right: So – my normal – guess which is new and which is old picture.
Clearly the old and broken one has a wider U-shape where it fitted into the failed rose bush.
It’s really when you start looking a lot closer though that you really get the sense of how much of an “Oh fuuuuuuck” moment this almost was.
Right: The rather terrifying close ups of the failed link arm
Good God – look at the crack in that transverse arm – I think “getting lucky” is something that I would definitely say here.
That crack is running just shy of 1/2 the way through that leg of the Y on the arm – and I doubt if a single side of a Y would be able to take up the strain of suspension movement on a normal British road of one side had decided to catastrophically fail.
So – what was the underlying cause for this link failure ?
A bloody bush.
A simple, less than £20 item.
These bushes are designed to have a fair degree of flexibility in all planes, to allow a degree of controlled movement in the suspension, and to give another layer of comfort to the occupants by taking some of the direct road vibration out at the rubber joint.
Right: Seriously – how broken is this bush ?
See how much rust there is on the *inside* of the rubber casing ?
I took a video of me trying to wiggle the bush, but it is pointless to post it, as you can’t tell there is any movement at all – and that is precisely the failure – no movement, and thus any movement that needs to be “taken up” by the bush is transferred to the transverse arm, and ultimately causes a fatigue failure.
Compare it to another bush that I took off the car, Right: – this one shows nice and shiny on the inside.
The new bushes are a of a completely new design, and aren’t “bearing bushes” – but appear to be solid lumps of rubber – they may well eventually perish, but it will be slow, and quite obvious – rather than this inside out corrosion and relatively quick failure.
Now – that’s my drivers side all fixed, I need to get on with the passenger side in part 3.
