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Discussion Starter #1
Howdy troops n troopettes hope all is well,

But it's come to that time of year/month/day again that alas, I need some help. Long story short, almost all the front suspension was replaced less than a year ago, covered less than 5k, last week had the front wheel bearings changed and the car handles beautifully.

However, there is a knocking coming from the passenger side (front left in UK) and my mechanic hasn't been able to find anything, this knocking has been there since before the suspension upgrades. It doesn't have any rhyme or reason to it either, sometimes driving in a straight line at 20mph does it, sometimes under braking, sometimes turning left or right, sometimes over 60mph on a straight motorway. As above, handling isn't compromised but I'd rather get it seen to and fixed so it doesn't become a long term issue.

Car is going in for a service in 3 weeks and he will take another look but I'm stumped as to what it may be, especially as it's all relatively new, 1 suggestion was engine mount may have warn but no idea from me.

Anyone had experience of this or have any pointers in what we should be looking out for at all?

Thanks in advance.

Chris
 

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Discussion Starter #4
Almost everything, so what was not changed?
Hi Paul thanks for the response, tbh just the sub frame, have had all the suspension and brakes rebuilt

Front upper and lower wishbones
Front anti roll bar
Front anti roll bar bushes
Front standard shock absorber's
Rear. Standard.10" shaft shock absorbers
Rear drop links both sides
Rear anti-rollbar and bushes
Eibach -30mm Springs all round
One of the top mounts was changed also as the bolts had sheared off.
All suspension bushes as well, pretty much every part that bolts on/off.

Also had all brakes and pads changed too.
 

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Discussion Starter #6
Top mounts? Intercooler support bracket?
Had the drivers side replaced when all the above work took place so it may be worth replacing also, thanks for the suggestion, only a 1.6TS no sure if she even has an intercooler? But well worth checking too :)
 

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Discussion Starter #7 (Edited)
As just said, the top suspension mounts, and maybe front drop links?
I just took the above list off a previous post, I'm sure I did the front drop links also, but will need to check my invoices, but top mount on that side definitely wasn't changed

Edit, front drop links were also done :)
 

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Does it sound like a typical suspension knock? Maybe some parts used were not the correct parts, but given that the noise was there before the suspension work as well as after indicates that would not be the case.

I'm not too knowledgeable but is there a chance it could be a steering component making the knock?

Could it be as you suggested an engine or transmission mount. That could be worth some more investigating.
 

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Discussion Starter #9
Does it sound like a typical suspension knock? Maybe some parts used were not the correct parts, but given that the noise was there before the suspension work as well as after indicates that would not be the case.

I'm not too knowledgeable but is there a chance it could be a steering component making the knock?

Could it be as you suggested an engine or transmission mount. That could be worth some more investigating.
Thanks Mike, definitely does sound like a typical knock, I'm leaning towards top mount currently, the suspension parts are definitely right as I sourced the parts from an Alfa specialist who ask for your VIN to make sure they'll fit your car and they also put the engine variants up so you know too :)
 

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Howdy troops n troopettes hope all is well,

But it's come to that time of year/month/day again that alas, I need some help. Long story short, almost all the front suspension was replaced less than a year ago, covered less than 5k, last week had the front wheel bearings changed and the car handles beautifully.

However, there is a knocking coming from the passenger side (front left in UK) and my mechanic hasn't been able to find anything, this knocking has been there since before the suspension upgrades. It doesn't have any rhyme or reason to it either, sometimes driving in a straight line at 20mph does it, sometimes under braking, sometimes turning left or right, sometimes over 60mph on a straight motorway. As above, handling isn't compromised but I'd rather get it seen to and fixed so it doesn't become a long term issue.

Car is going in for a service in 3 weeks and he will take another look but I'm stumped as to what it may be, especially as it's all relatively new, 1 suggestion was engine mount may have warn but no idea from me.

Anyone had experience of this or have any pointers in what we should be looking out for at all?

Thanks in advance.

Chris
Hi
First off all need to check left and right sway bar links those can make knocking sound on the ball joints,then second thing to look for is sway bay location has to be in the middle of the suspension,sometimes sway bar moved either to left or right so need to position in the centre and secure with two hose clamps next to the mounting point so does not move any where after good luck
 

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Funny that I missed this one until now.
Very carefully check the top wish one bush area for movement.
A little known phenomenon is the pivot bolt mounting the upper wishbones can wear/lengthen and cause excess movement.
This happens more someone puts off front damper replacement too long and the front suspension rattles itself apart.

As with many cars these days, ours don't respond well to penny pinchers as it always back fires. Obviously you didn't have your car long before getting that done which highlights the importance of history and a folder of receipts.
 

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I'd also suggest checking the top arm mounting bolts. The normal suspect is the bush, but the long mounting bolt wears ..

I fitted some really suspect quality drop-links .. and swapped them out for Mahle(?) heavy duty ones which were great.

Also had a knocking and this was down to the bolts holding the lower suspension arms being cross-threaded and one had completely stripped the threads on one front and one rear mount .. one bolt was on the garage floor!!
 

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Very carefully check the top wish one bush area for movement.
A little known phenomenon is the pivot bolt mounting the upper wishbones can wear/lengthen and cause excess movement.
I tend to doubt that the bolt would stretch as a result of the normal 'shear' loadings encountered in use. More likely the nut / bolt just becomes loose due to not being tight enough in the first place. Also possible, but I suspect unlikely, is that the bolt might be overtightened and as a result been at the very edge of its' elastic limit, then has permanently stretched slightly in use.

If the nut does become loose then the components that it is supposed to be clamping together won't be properly clamped, and so will move relative to each other. The abutting faces of each component may move slightly in the direction of any shear loadings, and also rotate against each other with any vertical suspension motion. These movements may cause wear over time, and if so cause any looseness to increase.

Also, if the nut loosens then the bolt might become somewhat worn / damaged due to repeated shear loadings and impacts. This would be because; with a loose bolt all the shear loadings and rotational movements would be imparted directly into and onto the bolt shank only. There would be 'rattling impacts' due to clearances between the bolt shank and the components through which it passes. The bolt may bend, or become worn on it's OD, but more likely any softer component through which it passes may become worn on its' ID (I'm thinking the aluminium casting through which the bolt passes more than the two steel bushes / crush tubes).

If the bolt is fully tight then very little (if any) of the normal shear loadings will be imparted into the bolt itself. All the load the properly tight bolt will 'see' is the tensile load that is the result of tightening the nut. This tensile force clamps all the components through which the bolt passes very very tightly together, so that the abutting faces of each clamped component is forced extremely hard against each other. This creates very substantial friction between each component, and it is this friction which resists the shear loadings, not the shear strength of the bolt per se.

If a bolt is properly tight, then in theory and in all probability there could be a significant clearance between the shank OD and the ID of the holes in all the components through which the bolt pases, without the components ever moving relative to each other or to the clamping bolt (or the bolt moving relative to the clamped components). It is normally the clamping force (i.e. the tensile load imparted by the tightness of the nut, bolt, stud, screw etc) which prevents component movement, not the 'shear' strength of the fastener.

Regards,
John.
 

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My wife drives a 159 that is so smooth everyone compliments it....mine is a 156 that rattles to high heaven......but by God,mine is so much more enjoyable to drive.
 

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Discussion Starter #16
Funny that I missed this one until now.
Very carefully check the top wish one bush area for movement.
A little known phenomenon is the pivot bolt mounting the upper wishbones can wear/lengthen and cause excess movement.
This happens more someone puts off front damper replacement too long and the front suspension rattles itself apart.

As with many cars these days, ours don't respond well to penny pinchers as it always back fires. Obviously you didn't have your car long before getting that done which highlights the importance of history and a folder of receipts.
Thank you, great to hear from you again my friend.
 

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Discussion Starter #17
I'd also suggest checking the top arm mounting bolts. The normal suspect is the bush, but the long mounting bolt wears ..

I fitted some really suspect quality drop-links .. and swapped them out for Mahle(?) heavy duty ones which were great.

Also had a knocking and this was down to the bolts holding the lower suspension arms being cross-threaded and one had completely stripped the threads on one front and one rear mount .. one bolt was on the garage floor!!
Thanks Gazza, another thing to look into.
 

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Discussion Starter #18
I tend to doubt that the bolt would stretch as a result of the normal 'shear' loadings encountered in use. More likely the nut / bolt just becomes loose due to not being tight enough in the first place. Also possible, but I suspect unlikely, is that the bolt might be overtightened and as a result been at the very edge of its' elastic limit, then has permanently stretched slightly in use.

If the nut does become loose then the components that it is supposed to be clamping together won't be properly clamped, and so will move relative to each other. The abutting faces of each component may move slightly in the direction of any shear loadings, and also rotate against each other with any vertical suspension motion. These movements may cause wear over time, and if so cause any looseness to increase.

Also, if the nut loosens then the bolt might become somewhat worn / damaged due to repeated shear loadings and impacts. This would be because; with a loose bolt all the shear loadings and rotational movements would be imparted directly into and onto the bolt shank only. There would be 'rattling impacts' due to clearances between the bolt shank and the components through which it passes. The bolt may bend, or become worn on it's OD, but more likely any softer component through which it passes may become worn on its' ID (I'm thinking the aluminium casting through which the bolt passes more than the two steel bushes / crush tubes).

If the bolt is fully tight then very little (if any) of the normal shear loadings will be imparted into the bolt itself. All the load the properly tight bolt will 'see' is the tensile load that is the result of tightening the nut. This tensile force clamps all the components through which the bolt passes very very tightly together, so that the abutting faces of each clamped component is forced extremely hard against each other. This creates very substantial friction between each component, and it is this friction which resists the shear loadings, not the shear strength of the bolt per se.

If a bolt is properly tight, then in theory and in all probability there could be a significant clearance between the shank OD and the ID of the holes in all the components through which the bolt pases, without the components ever moving relative to each other or to the clamping bolt (or the bolt moving relative to the clamped components). It is normally the clamping force (i.e. the tensile load imparted by the tightness of the nut, bolt, stud, screw etc) which prevents component movement, not the 'shear' strength of the fastener.

Regards,
John.
Great info as usual John, thank you.
 

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Discussion Starter #19
My wife drives a 159 that is so smooth everyone compliments it....mine is a 156 that rattles to high heaven......but by God,mine is so much more enjoyable to drive.
My rear tyres have a slow puncture (Getting replaced when I get paid) but by the end of the week the pressure has dropped to about 14 psi so the back end slides about, it's a great laugh!
 

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No worries.
once again my comments come from (frustrated) experience. As the bushes wear, the clamping force reduces but it tends to be overly soft dampers which causes the bolt to wear as the front suspension rattles even over the most minor surface imperfections.

I've found that worn dampers cause greater bolt wear than a hard driven car with good dampers. A good place to buy the bolt is Jamie Porter's Alfa Workshop- just add dot co dot UK.
 
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