UrS4; Front end knocking noise

[hunker7]

it's me....again! I used to get knocking noise from front suspension when going over speed bumps, but I always thought it is due to my knackered subframe bushes.

I installed solid subframe bushes on Sunday and torqued everything up as it should....but noise still isn't gone. Sounds like shock absorbers bottoming, but considering I'm running less than year old Bilsteins, it seems doubtful. It happens more frequently since I've fitted solid bushes, if roads get little bit rougher it'll knock away

I had car on the ramp today and I cannot see anything at the bottom that could make that noise. Exhaust has chain hangers and doesn't seem to touch anything. Could it be gearbox hitting subframe? (I have changed gearbox mounts too).

Every single suspension bush/mount is new, new engine mounts and gearbox mounts, there is nothing left to change.

Here is a video and you can hear the noise at 3s, 10s and 13s

[UrS4boy]

What brand did you use for Item 36, Suspension Strut Bearing?

Cheap Chinese ones fail very quickly (rubber separates from the inner metal furrel) and when any of the Item 36 strut bearings fail, they bang and rattle. Take the plastic beauty cap off the top of the strut and watch the top of the strut while you push down (put your weight on) the front fender.

C4 UrS Front Suspension Parts including PNs and hints:

http://forums.quattroworld.com/s4s6/msgs/24392.phtml

Front Strut Bearing DIY:

http://forums.quattroworld.com/s4s6/msgs/318201.phtml

Item 36 (not the highlighted Item 33):

[hunker7]

Used Febi brand so not Chinese crap. I will take top mounts off tomorrow just to check as I've checked everything else too and while it's all off I'll check shock absorber cap to see if that's tight.

Odd that it got worse once bushes were done

[hunker7]

Knocking can be felt in the footwell. Doesn't seem to be coming from up top.

[hunker7]

Just checked top suspension mounts and they're all good. No cranks or anything.

[UrS4boy]

C4 UrS Front suspension PNs, hints and torque values

Knocking can be felt in the footwell. Doesn't seem to be coming from up top.

Lower control arm. Bushing (LCA) Sleeve. Rubber. Bolt. Items 1, 10, 3, and 11 below. People tend to forget about 10 when changing the LCA. Also the three 12 point head subframe bolts can work loose if not torqued proper. Item 18 on page 1 in the pdf below:

Front Suspension PNs and hints: http://forums.quattroworld.com/s4s6/msgs/24392.phtml

http://12v.org/urs/FrontSuspensionTorqueValues.PDF

Lower Control Arm replacement DIY:

http://forums.quattroworld.com/s4s6/msgs/226796.phtml

[tekstil]

Check that the shock absorber fastening cap is tight (item 26). My friend had similar problem with his V8 which turned out to be the cap.

[hunker7]

I think I might have found a problem after 2 passengers said noise is coming from the back. I guess there is more forwards/backwards movement in the diff/prop/gearbox and something is banging at the front?

[Majorcina]

I think you found your problem mate

[Rikki Kitto]

Rear end refurb on the way then bud might as well do the lot while your in there

[hunker7]

I have changed suspension arm bushes but not subframe, diff carrier or the big diff bush so I think I will have to soon put an order in at AK for some solid subframe bushes and poly bushes for the rest.

[Vorsprung durch Technik]

Doing the rear is much harder Janis. But with your ramp now should be a lot easier.

[hunker7]

Doing the rear is much harder Janis. But with your ramp now should be a lot easier.

See can't get on the ramp for more than an hour or so unfortunately as it's at work. But I'm planning on possibly getting spare subframe etc and do a swap over anyways. But we'll see when the time comes.

[Vorsprung durch Technik]

See can't get on the ramp for more than an hour or so unfortunately as it's at work. But I'm planning on possibly getting spare subframe etc and do a swap over anyways. But we'll see when the time comes.

That's the best way if you can,out with the old and in with the spare rebuilt one sharpish.

[hunker7]

That's what I did with front but as you said front us much easier.

Any idea how much subframe, diff carrier and ARB go for?