OSF Knocking, struggling to pinpoint! Help appreciated

[Piggy22]

Good afternoon

For some time the OSF has been knocking and i just cant get to the bottom of it

It has got worse the past few days but i can pinpoint it at all

The last 4 weeks has been trial and error after Unit 20 suggested the lower arms. Although no movement in them, the arms were not genuine units fitted by the previous owner. Its been on the ramp many times and to be honest i have just changed parts just in hope that i would catch it. Fail

I have changed both lower arms, droplink, wheel bearing (this did rectify a different clicking noise on setting off/braking) and top arms. All genuine Audi units used

Its driving me nuts now. It is noticeably worse when reversing and turning at the same time I.E into a parking space. This usually emits a loud knock. Otherwise its just a irritating knock/tapping whilst driving down the road

The shocker unit is Bilstien and is about 4/5 years old, the track rod end seems fine too but does anyone else have any idea what the cause could be before i change these too

Thanks in advance

[Shoppinit]

Did you change the top strut mounts?

[Piggy22]

Did you change the top strut mounts?

No i havent changed this as of yet

I was wondering if the mounts are just standard audi units i can get from TPS or are they special mounts because they are Bilstien shock absorbers?

Thanks

[Shoppinit]

They are just the standard VAG ware.

[Piggy22]

They are just the standard VAG ware.

So best place is TPS, they will be ok finding a top mount kit from the reg?

Thanks in advance

[Ben_r1]

I got a pair from ECP for £80 they’re SKF so good quality too.

To be honest though there’s no bearing and the rubber components are minimal I can’t see how they would wear to the point of knocking.

[Shoppinit]

Possibly ARB bushings.

CV joint. Inner or outer.

Loose steering rack bolts.

[Piggy22]

Possibly ARB bushings.

CV joint. Inner or outer.

Loose steering rack bolts.

ARB links and bushes have been changed

Outer cv joint and bolt on wheel bearing has been changed

Loose steering rack bolts? Where are these if you can point me in the right direction? Under the scuttle panel at the back of the engine bay?

Cheers

[Nobby]

Have you checked your subframe bolts? Steering rack bolts are hard to find! Very hidden (hence almost impossible to remove the rack without dropping the engine - but it can be done)

[Ben_r1]

There is something I’ve read before about an infamous steering rack bolt number 3? Which is commonly known for loosening but almost impossible to access with the engine in.

[Mɐʇʇ]

Not that I need to access it - but intrigued to know how that can be done?

[Piggy22]

Code: Select all

Have you checked your subframe bolts? Steering rack bolts are hard to find! Very hidden (hence almost impossible to remove the rack without dropping the engine - but it can be done)

Yes all subframe bolts have been checked

I am just about to change the strut top mount for an SKF item and the track rod end

Lets hope this cures it

[Piggy22]

A bit of an update

I stripped the chassis leg today and took the shock absorber and top 2 control arms out. I replaced the 2 piece top mount kit and then when i went to bolt it all back up i noticed something

The 3 bolts at the to which bolt the top of the shocker to the leg, i noticed the bolt closest to the bulkhead had some fragments around the whole thread! Upon looking at the threads on the top mount, they had been stripped! Closer inspection suggested it had been like that for some time as they were not shiney, but dull.

I helicoiled the thread M10 x 1.5 and then bolted it all back up

I sprayed all in between rubber bushes on all of the arms with WD40 for good measure

ALAS THE NOISE WAS NO MORE.......for 100 miles

Now its just a creaky boat on the same corner when turning etc

What to do next......help very much needed with this one

[Shoppinit]

Sounds like the bolt was a red herring and the wd40 temporarily fixed the creaking.

[Piggy22]

Sounds like the bolt was a red herring and the wd40 temporarily fixed the creaking.

So it seems. I am going to spray it all again and see if it goes away and then wait for it to come back just to spray each joint individually and hopefully track the fault down

Every item is new and they are genuine units from TPS so i am really confused as to what is going on

Open to ideas guys