147 Suspension Issues

[John Hanslow]

I have a noticed a knocking from underneath the front of the car.  You can feel it under your feet and thru the pedals.  You really notice it on bumpy roads (read poor quality suburban roads) and especially when cornering.

I have been advised that it is the suspension bushes on the front sway bar that have perished and that you need a new bar that is tricky to replace as the sub frame needs removing along with the exhaust.

As an alternative, I also heard that you can drill out the fittings on the bar and indeed you only need to replace the bushes at a considerable cost saving.

Anybody got some info on all of this ?

[Davidm1600]

Hi John

I can't specifically comment on the 147's front end, but if they are at all remotely similar to say the 156, I would wonder if perhaps rather than the sway bar bushes, is whether or not it might be in fact as I need to do with my 156, that is replace the upper control arms.  The bushings on these do with age wear, and you simply replace the control arms. I only suggest this as I have a knocking sound from the front of my car, when driving on bumpy roads.

If so, check out the cost of replacement items from EB Spares.  That is where I got mine from and they weren't too expensive.  I also bought new sway bar bushes and will have these installed.  The front of my car squeaks quite a lot, and my mechanic noted this was the typical of the sway bar bushes.  The cost minimal for new bushes (from memory 4 UK pounds per bush).  I am going down the route you mention.

[wankski]

no. the kocking at the feet is def ARB.

you can replace the bushings... stnd parts are only 6 quid from EBspares...

it is easier to get the whole ARB tho and replace... better still source the upgrade ARB kit from ebspares.
http://www.ebspares.co.uk/alfa_147/Rubber_body_to_bar_bushes_22mm/info.cfm

be warned.. labour not very cheap on this job. drop subframe is necessary. approx $300-400 i should imagine.

the risk w/ bushing only is finding the metal bar has worn under the bushing and having knocking return in short order.... i would hazard bush only replacing is worth while DIY... otherwise, advise dropping the 80 quid and getting the bar... (also ebspares) better yet, seriously consider the eibach ARB. best mod ever for no detriment. IMHO anyway. refresh drop links too.

alfisti are expecting the eibach ARB in soon (i'm on backorder) and there is no issue waiting... u wont mess up anything driving it as is.

[Davidm1600]

Wanaski, is the issue you are talking of re for the 147 or 156. 

If both, that that would appear contrary to the advice I have always seen regarding knocking noises from the front end in this model.  Ditto the advice received from both my Alfa mechanic and the Alfa dealer here as well as from EB spares themselves.  I asked Kevin at EB the question, hence the advice to replace the upper control arms, and not to use the cheap ones on ebay.  As I say perhaps the issue John has is different to what I have with my car.

As to replacing the sway bar bushes, well I am happy to go with trying this first as it is a lot cheaper and easier to do.  I will be installing Bilstein B4s in my car at the same time as I am doing the other work there.  To me that should be sufficient without going down the whole Eibach suspension upgrade, as good as that may be.

I read somewhere on line here in a forum about some guy who had the knocking problem in the front end and went the whole hog including the drop links, only to find out that it as the upper control arms and sway bar bushes that was all he needed. 

Time will tell in my case.

[wankski]

yes, read what u wrote again... he replaced the ARB bushes... that's where the knocking is.

it is unlikely for the knocking to emanate from the top bones, they do not really carry any load! I have stripped the suspension of my 156, the 147 is identical. down to the part no. when they go the bushing goes dry and they squeak, altho the ball joint can go too, but less likely as the bushings die first.

the point is, its at the feet. that is where the ARB mounts up - also bad during cornering... connect the dots...

the main load of the strut assembly is the strut mount to the tower and the lower point is indeed the lower wishbone connected to the "tuning fork" that grabs the damper body. the  upper wish bones locate the top of the brake upright, it's an alignment tool. the long bolt that binds it to the strut mount could be loose, it would still do the job as tightening really only binds the inner metal sleeve to rotate inside the rubber bushing of the top bone.

the reason why the arb knocks is b/c the bushings collect grit and grind around on the arb as it works in torsion. as one strut is compressed the drop link on the lower tuning fork pushes down on one 'arm' of the bar which twists and transfers that force to the other side to utilise the spring on the other side to resist the rolling motion in a corner... the bigger dia the bar the great force transfer, teh greater the unloaded inside spring is utlised to resist roll. it's win-win as it works on an otherwise stock set up.

but the torsion bar action is also why the bar under the bushing can be worn as it twists and grinds down w/ grit caught in the bushing.... the bushing wearing away and drying out creates the necessary gap against the bar so that when the bar 'arm' is depressed the whole bar moves up and down against its two central bushing mounts. each in front of the driver and pass footwells. again, the top wishbones do not have that kind of force (of the whole car body weight) working thru them. they are only alloy! basically anything carrying the whole weight of the car is steel/iron (i.e. lower arms, arb, etc)...

agreed re: OEM only.

re: eibach. to be clear i was referencing the eibach arb bars only. not the full suspension kit.

NB: if you want to settle the issue. disconnect the drop links on the front arb and take it for a gentle drive with corning in some empty side streets/large carpark... noise still there? ain't your ARB! noise gone... issue settled.

not a bad diag esp. as it can cost a fair bit to change the arb.

[wankski]

it is an easy job to do:

jack up wheel, USE axle stand. remove wheel.

use ring spanner 17 or 19mm can't remember on the bolt holding the drop link onto the alloy fork mount on the strut. a ratcheting type ring spanner makes life easy for this job.

utilise allen key, either 5 or 6mm to hold the drop link bolt still while you TURN the nut w/ the ring spanner. do not attempt to turn the allen key, u will strip the stud which is apparently made of cheese. AMHIK!

with the nut off you can remove the drop link by withdrawing the stud/bolt through the eyelet in the strut fork, both ends are on free ball joint like pivots... zip tie it to keep it secure and not to knock around or remove the other end in the same fashion and totally remove the link...

repeat on other side. simples.  blast the bolts with freeze release before doing this to make life a lil' easier.

HTHs.


you can see here what the top wishbone does, it locates the upright to remain vertical under strut compression. here the ball joint is popped w/ the upright. The weight bearing strut behind is still fully connected w/ the chassis and lower arm.

a nice pic of how it all works and bolts together.

[L4OMEO]

Good thread. FWIW, my understanding is that worn control arm bushes are usually preceeded or accompanied by a degree of squeaking and the knocking is lighter and heard more than felt; with the ARB, the knocking is deeper, more of a 'clunk', and clearly felt through the footwell. While that's not a particularly scientific it may help in the initial diagnosis.

Sadly, I have developed a 'clunk' over the past few weeks so I'll have the opportunity of testing the above theory   

[Davidm1600]

Thanks Wanaski and L4omeo, that answers and clears up a lot of misinformation or misunderstandings re this whole malarky.  I can certainly see the logic in the engineering/technical explanations given.  Ditto re the differences in sounds (knocking squeaking mentioned).  Hopefully this also will help John in sorting out the problems with his 147.

Just to confirm though, if I understand correctly, you are saying that replacing the top control arm won't or at least is unlikely to fix the knocking problem ??  However, given I have bought the new parts including the top bolt, is is worth changing these ?  Perhaps given I have them already.

Also, and given what you are saying re the benefits of the Eibach ARB kit, would I be better off getting this and not bother using the ARB rubber bushes I have already bought.  If so, I will need to get back to EB to order one of these.  I want to get all my problems fixed and at the same time rather than having to revisit this issue. 

I am currently waiting on the timing belts etc parts to arrive, so it gives me time to sort out the rest of what I need.  I take it though I don't need to replace the lower control arms. 

What normally is the issue with the drop link (ie the ball joints ?), and should this also be replaced, given it is not cheap due to the need to drop the subframe ?

[wankski]

Just to confirm though, if I understand correctly, you are saying that replacing the top control arm won't or at least is unlikely to fix the knocking problem ??  However, given I have bought the new parts including the top bolt, is is worth changing these ?  Perhaps given I have them already.

yes. if your car is over say 6 yrs and 100k kms, replace em if u got oem ones. its a 20min job per side for someone with experience to swap em out. I swapped mine out as i was installing new dampers and springs in my car above. the dampers were TOAST. oddly, my upper arms were perfect and looked original. lucky i guess.

Also, and given what you are saying re the benefits of the Eibach ARB kit, would I be better off getting this and not bother using the ARB rubber bushes I have already bought.  If so, I will need to get back to EB to order one of these.  I want to get all my problems fixed and at the same time rather than having to revisit this issue.  

if you are doing the job yourself, i would give the bushing a crack, just don't be surprised if it comes back after a few months... the bar is gone... i guess eibach's arb is a given if you are into modifying, if not, i can understand that... just be advised that alfa recommendation is to replace the bar as a kit, and it is also for sound reason too... personally i'd be pissed if i spent $400 in labour to get someone to put bushings in, and inside a year later i need to do it again... all just to save maybe $130. A new bar and drop links guarantee refreshed front ARB.

I am currently waiting on the timing belts etc parts to arrive, so it gives me time to sort out the rest of what I need.  I take it though I don't need to replace the lower control arms.

check em out... the lower bar - you can see where it is connected to the sub frame in the pic... these bushings go, u will get play - and there is load here... but generally a lower will last thru 2 uppers... should be ok, but the best bet is to check em when u pop the upper bone ball joint, so u can freely pivot the upright/brake assembly and try to wiggle the lower arm fore and aft (relative to the car) to check for play.... inspect the bushing too to see if it has dried out or perished.... pray its all good, as the lowers are more expensive and a bit of a pain to do... the lowers tend to groan under bumps as the lower deflects... uppers by contrast usually squeak and the noise comes from behind the dash clearly... if the ball joints are dead or if the lower is so bad its loose it can knock... but usually the ball joints on these last longer than the rubbers, unless the protective boot has been ripped.

What normally is the issue with the drop link (ie the ball joints ?), and should this also be replaced, given it is not cheap due to the need to drop the subframe ?

yes the drop links can have excessive play. they ought be replaced any time you extract the ARB. luckily the drop links are cheap, 12 quid? ebspares do em... to be clear the drop links are easy to replace in the manner i described above. Its the actual ARB that is a pain as the subframe comes off for it. there is a way to do it with the subframe on, but it doesn't save anytime... in fact can be more painfull. just saves clearance issues on a driveway if DIY.

the drop links are the brass coloured things in the photo i posted labelled (wrongly) "remove its came off very easy this is anti roll bar" - what it is pointing to is the drop link. as mentioned. allen key and ring spanner to remove.

[Davidm1600]

Thanks Wanaski, your explanations really help me a lot.  Now I really know what to do.  Just need to wait until all the parts I need have arrived from EB.  Will get onto getting the extra parts needed. 

I look forward to having the front end of my car perfect once more, oh and yes my dampers are as soft as a camenbert, hence the Bilsteins on order 

[John Hanslow]

Thank you all for the info.

It really puts things in perspective.

I can confirm that the knocking feeling was felt thru the floor and pedel.  A quick inspection and 'push/probe' indicated that the sway bar was somewhat loose and replacement was the order.

I will be taking it to my local Alfa Specialist for a full report next week so I can look at my options.

Cheers

[colcol]

Thank all the local councils for putting speed bumps everywhere, or in their talk, 'traffic calmers', Colin.

[John Hanslow]

Here is the result and the summary:

- Supplied and fitted lower control arms
- replaced link for stabilizer .

Can not believe how quiet and firmer it feels.  It actually makes the Ti suspension experience now quite firm yet positive experience nstead of 'rattle and hum'.

Perfect drive - just like a new car (almost).

Perhaps time for further improvements or upgrades ...

[Neil Choi]

Perhaps time for further improvements or upgrades ...

Yes John.

147 GTA.

But I can't afford it, @$1.60-1.70 a litre and running 16-17L/100km.

[wankski]

- Supplied and fitted lower control arms
- replaced link for stabilizer .

so it was the drop link causing the clunking? was their boot torn?