Front suspension top mount help

freakyeke

freakyeke

A2OC Donor
I have recently refreshed the suspension on my 1.6 FSi Sport.

I have fitted the following components:
Bilstein B4 shock absorbers
Eibach Fabia lowering springs
Bilstein Febi bump stops and dust covers (cut -20mm)
Meyle drop links
Meyle top mounts and bearings

Everything fitted and torqued up to manufacturers recommendation. My problem is that the front offside top mount emits a sharp crack when driven over a pot hole. The passenger side is fine.

I've checked everything is properly located and it is.

I'm all out of ideas and am looking for some inspiration.

Thanks.
 
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There are two parts to the top mount, the bearing itself and the part that it sits in, Have you missed out the other part?


top mount.JPG
Also,

are you sure of the source of the noise, you should try to reprodiuce the noise when stationary, so you can pinpoint the source.

If it is not a very crisp noise could it be coming from the rear corner of the bonnet, a quick tap on each corner with the side of your fist, should reproduce that particular noise.

Steve B
 
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Thanks for the quick response, Birchall ;)

I have tried to recreate the noise when stationary, but, it only happens on the larger pot holes or steep speed bumps.

I will be happy if it is the bonnet. I'll go give it a thump now, although, the noise was absent before I changed the suspension.
 
freakyeke said:
Thanks for the quick response, Birchall ;)

I have tried to recreate the noise when stationary, but, it only happens on the larger pot holes or steep speed bumps.

I will be happy if it is the bonnet. I'll go give it a thump now, although, the noise was absent before I changed the suspension.
Click to expand...


Yes, but you have had the bonnet off and put back on again since then, that was why it was worth a knock, shame it wasn't that.

But be very careful, this could be something critical.

Is the bottom mount (where the strut goes into the holder) ok?

Also it is often the drop links when you get a knock over pot holes, check that they are secure too.

I hope it is not related to the lowering you have done?

Steve B
 
Everything is secure and tight. The noise is definitely coming from the top area of the suspension. Although, I may be proved wrong.

I'll keep plugging away to find out what it is.

Thanks for your help, Steve.
 
Have you checked the ball joints on the wishbone? My old bmw 330 had a bad one and it sounded terrible when hitting potholes.
 
Did you fit new top bearings? These things are the Achilles heal on the A2. They often sieze and you'll hear the coil spring twang when turning due to the friction. Double check the strut bolts inside the engine bay too. The driver's side is a pain to access due to the brake fluid reservoir. Raise the car and get a scissor jack under the wishbone to raise up slightly.
 
You're not kidding about the driver's side. What a nightmare.

I've fitted new Meyle balljoints and new top bearings so doubt it will be either.

Thanks for the input guys.

I may strip it down and start again, just to be sure.
 
Couple of other things to check before you strip it down again.

When you fitted the new Bilstein struts into the hub carrier, did you grease them with engine oil? Part of the reason for doing this is to get them to fully locate. I also used a wedge to open slightly so the strut drops down fully into the aperture.

In addition, check the spring. There should be locating tabs that the coil spring sits in. It's easy enough for the spring to sit outside these tabs if not fitted correctly. Ensure the spring ends fully locate with the stops on the upper mount and spring seat base.

Lastly, have you renewed the ARB bushes? I know you say it sounds like the top, but best rule everything out.
 
spartacus 68 said:
Couple of other things to check before you strip it down again.

When you fitted the new Bilstein struts into the hub carrier, did you grease them with engine oil? Part of the reason for doing this is to get them to fully locate. I also used a wedge to open slightly so the strut drops down fully into the aperture.

In addition, check the spring. There should be locating tabs that the coil spring sits in. It's easy enough for the spring to sit outside these tabs if not fitted correctly. Ensure the spring ends fully locate with the stops on the upper mount and spring seat base.

Lastly, have you renewed the ARB bushes? I know you say it sounds like the top, but best rule everything out.
Click to expand...

Spring fitted to bottom stop, inside shock mounting perch, I can't remember there being a stop on the top (underside of bearing), it was just a smooth surface plate.

The shock is fully located. I made a spreader tool with a 10mm bolt and ground down 2 flat sides to around 5mm. Works a treat.
I also checked the ARB bushes and they seem firm and in place.
 
freakyeke said:
Spring fitted to bottom stop, inside shock mounting perch, I can't remember there being a stop on the top (underside of bearing), it was just a smooth surface plate.

The shock is fully located. I made a spreader tool with a 10mm bolt and ground down 2 flat sides to around 5mm. Works a treat.
I also checked the ARB bushes and they seem firm and in place.
Click to expand...

I'm probably confusing the top mount with my other car. Done both of them on the A2 and A4 recently.

Keep us posted on how this gets resolved. :)
 
I stripped down the driver's side shock absorber today and then refitted it. I took it for a drive and purposely drove over some pot holes. There are no noises but I don't know why, as there was nothing obviously loose or incorrectly fitted?

I'm happy again ;)

Thanks for the help, gentlemen. It's much appreciated.
 
freakyeke said:
I have recently refreshed the suspension on my 1.6 FSi Sport.

I have fitted the following components:
Bilstein B4 shock absorbers
Eibach Fabia lowering springs
Bilstein Febi bump stops and dust covers (cut -20mm)
Meyle drop links
Meyle top mounts and bearings

Everything fitted and torqued up to manufacturers recommendation. My problem is that the front offside top mount emits a sharp crack when driven over a pot hole. The passenger side is fine.

I've checked everything is properly located and it is.

I'm all out of ideas and am looking for some inspiration.

Thanks.
Click to expand...


worth a shot, just give the drop link nuts an extra 1/4 turn tight as my petrol A2 done a simular thing on first run after replacing the complete suspention , after hunting for an eternity to no avail it turned out to be the drop links even thow tight and no play apparent there was slight movement so got a high pitch tap , crack metal to metal noise , cured by going slightly tighter than torqued
 
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