Steering Clunk at Manoeuvring Speed

[a8 tech]

As mentioned its the lower section of the column when on a slow lock you get a dull thud, replaced a good few and if memory serves me even a technical product information article which advises lubrication and correct installation of the protective rubber sleeve in the bulkhead

RS4 suffered from support bolts backing off in the plenith chamber and the lower rear arm reflex bush was to weak for RS4 hence rebound knock

B8 rack is mounted under engine and they are either assisted with hydralic or 2011 ish onwards electric

[CLP Automotive]

I'll just crawl back to my corner!

I don't know why i was thinking it was a B6/B7 A4.... the teachers always used to say i should concentrate more at school!

Yes you are correct there is a TPI about the lower section of the column, I believe it states to lubricate to see if there is any improvement or if not then replace.

Also I have replaced lots of Nearside Front Tie arms due to excessive play on the B8 A4's, they didn't normally cause much noise, not to the extent that they clunk but its always worth a look.

[Embisix]

Thanks for your input all.

It only happens once the car is up to temperature, why would this be?

My theory is that the lower column is warmed by radiated heat from (perhaps) the exhaust, maybe causing something to expand slightly, therefore exacerbating the wear/dryness in the joint?

That could of course be utter nonesense, but I can't help thinking about these things....

[CLP Automotive]

I think i would definately be trying to lubricate the lower universal joint of the steering column when it connects to the rack and if that makes any difference at all then you know your in the right area even though it might req replacement as the technical bulletin does say. I would Also make sure the heat shields around that area are free from contact with and moving parts as these are bent very easily when carrying out repairs, ie. gearbox removal, drive shaft removal.

[Embisix]

I think i would definately be trying to lubricate the lower universal joint of the steering column when it connects to the rack and if that makes any difference at all then you know your in the right area even though it might req replacement as the technical bulletin does say. I would Also make sure the heat shields around that area are free from contact with and moving parts as these are bent very easily when carrying out repairs, ie. gearbox removal, drive shaft removal.

I might have a crack at this myself before throwing a load of wedge at the dealer. Which lubricant would you recommend, anything specific? Also, would access be fairly easy (i.e. a case of removing the undertray and there she is?

Thanks

[CLP Automotive]

You would need to get the front end up on axle stands and then remove the rear undertray. You will then see the lower section of the column and the rack. There is a M10 spline bolt that pinches the column section to the rack (only fits on in one place so as long as you dont turn your steering wheel 360 degrees you'll be fine) Once you have removed the bolt you can pull the column section away from the rack. Once you have it off you can see if you can feel any excessive play and if not then lubricate and pop it all back together.

I would probably use quite a thick grease if i was doing it myself, like a clutch spline grease?

[Embisix]

Well, had her up in the air (the car that is!), took the rear undertray off and had a good poke around.

Noticed that the UJ just aft of the rack is literally 1cm from the exhaust, seperated by a very thin heat shield which can't be good. Cracking piece of design Audi, well done! This seems to be another compromise with the conversion to RHD!

The UJ itself was as dry as a proverbial. I couldn't remove it from the rack itself (as I don't have a suitable spline bolt wrench) but couldn't detect any excessive play. That's not to say there isn't any of course.

Anyway, packed the UJ with copious amounts of Lithium-Moly grease (the sort that goes into CV Boots) and also packed the UJ in the cabin while I was at it.

Alas, the thud has returned so I suspect there is some wear in the UJ on account of lack of lubrication and exposure to heat over time.

The car is going into Audi for discs and pads on Thursday, so they'll need to take a look unfortunately.

It's not all bad however as I'm now armed with some useful info. I know how long it takes to get to the offending part (all of 5 minutes!) and have a pretty good idea of how long it would take to remove it (no more than another 30 mins I'd say). So at least now when they quote for the labour, I'll know if they're trying to pull my trousers down :-)

Also, now it's nicely lubed and if the UJ is the problem, it shouldn't get any worse....

[Embisix]

So, for anyone who's interested, an update from Brighton Audi.

They've checked everything and there's no play in anything, anywhere. They've also swapped-out the suspected lower steering column bulkhead to rack section). No joy, still a thud.

They're keeping her in for observation overnight and will be fitting a new lower half of the steering column (the exposed section inside the cabin). This is thankfully much cheaper than the part we all suspected it was.

Failing that, the next step is the rack. Please no, not the rack! I'm going on holiday in 2 weeks, I can't be spending £1500.00 on a new bleedin' stering rack as well!

I'll know more tomorrow.... :-/

[Embisix]

Well, they tell me that it was in fact the lower half of the steering column (the exposed section inside the cabin), so the least expensive component at £311 fitted. They are confident the issue has been resolved, but time will tell.

I'll be taking the car on a 250-odd mile round trip tomorrow, so fingers crossed it's all sorted.

[Embisix]

Sorted!

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