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OSF Knocking, struggling to pinpoint! Help appreciated
Posted: Mon Jun 04, 2018 2:22 pm
by 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
Re: OSF Knocking, struggling to pinpoint! Help appreciated
Posted: Mon Jun 04, 2018 2:35 pm
by Shoppinit
Did you change the top strut mounts?
Re: OSF Knocking, struggling to pinpoint! Help appreciated
Posted: Mon Jun 04, 2018 2:41 pm
by Piggy22
Shoppinit wrote: ↑Mon Jun 04, 2018 2:35 pm
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
Re: OSF Knocking, struggling to pinpoint! Help appreciated
Posted: Mon Jun 04, 2018 5:33 pm
by Shoppinit
They are just the standard VAG ware.
Re: OSF Knocking, struggling to pinpoint! Help appreciated
Posted: Mon Jun 04, 2018 9:01 pm
by Piggy22
Shoppinit wrote: ↑Mon Jun 04, 2018 5:33 pm
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
Re: OSF Knocking, struggling to pinpoint! Help appreciated
Posted: Mon Jun 04, 2018 10:32 pm
by 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.
Re: OSF Knocking, struggling to pinpoint! Help appreciated
Posted: Mon Jun 04, 2018 10:42 pm
by Shoppinit
Possibly ARB bushings.
CV joint. Inner or outer.
Loose steering rack bolts.
Re: OSF Knocking, struggling to pinpoint! Help appreciated
Posted: Tue Jun 05, 2018 9:41 am
by Piggy22
Shoppinit wrote: ↑Mon Jun 04, 2018 10:42 pm
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
Re: OSF Knocking, struggling to pinpoint! Help appreciated
Posted: Tue Jun 05, 2018 11:35 am
by 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)
Re: OSF Knocking, struggling to pinpoint! Help appreciated
Posted: Tue Jun 05, 2018 12:10 pm
by 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.
Re: OSF Knocking, struggling to pinpoint! Help appreciated
Posted: Tue Jun 05, 2018 1:36 pm
by Mɐʇʇ
Not that I need to access it - but intrigued to know how that can be done?
Re: OSF Knocking, struggling to pinpoint! Help appreciated
Posted: Tue Jun 05, 2018 1:36 pm
by Piggy22
Nobby wrote: ↑Tue Jun 05, 2018 11:35 am
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

Re: OSF Knocking, struggling to pinpoint! At my wits end
Posted: Thu Jun 07, 2018 9:49 pm
by 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
Re: OSF Knocking, struggling to pinpoint! Help appreciated
Posted: Thu Jun 07, 2018 11:11 pm
by Shoppinit
Sounds like the bolt was a red herring and the wd40 temporarily fixed the creaking.
Re: OSF Knocking, struggling to pinpoint! Help appreciated
Posted: Fri Jun 08, 2018 2:05 pm
by Piggy22
Shoppinit wrote: ↑Thu Jun 07, 2018 11:11 pm
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
