I've been chasing a rattle (yes I know it could be anything) which seems to be coming from the front strut area on both sides of the car. Only evident on fairly poor roads and usually when I go over fair sized ridges running 90deg to the direction of travel. It's a metallic sound and can range from an annoying rattle to a clunk. Although I think the clunk may be when the strut has just been allowed to fully extend when dropping off a ridge or into a pothole.
Subframe bushes have recently been replaced with poly, recent B12 suspension, new droplinks and poly arb bushes.
I took a look at my control arm bushes again today. There's little up/down movement on either of them but a lot of fore/aft movement.
I've actually just booked it in for it's MOT in August and will have new arms fitted then (along with a new cat back) anyway as they seem a bit tired. But would the movement shown in the video linked below cause any concern?
I went for my second COVID test so far, last night in one of the drive through centres and when I drove over one of the cable trays a little too quickly, it sounded like the ar5e had dropped out of the car.
Good poke around today and I can't see anything else upfront that's obvious. And what I'm hearing may well just be a function of the B12 and poly subframe bushes??
https://www.dropbox.com/s/zl9r81mtg5m0rz9/2020-07-17%2011.24.43.mp4?dl=0 (https://www.dropbox.com/s/zl9r81mtg5m0rz9/2020-07-17%2011.24.43.mp4?dl=0)
Did you replace the top mounts when you changed the front struts? If so, what mounts did you use?
I changed my front struts four years ago and they came with "free" unbranded top mounts. These only lasted 500 miles before the rubber came unbonded from the body of the mount. The noise was only apparent on bumps. It might have got worse, but I got them changed after a nervous 2000miles drive around Germany and home.
If the car is firmly sat on the ground, the strut should be held in place and you can take off the top plate and have a look. Are the strut tops in the middle of the hole? One of mine wasn't.
I split the mount and the source of the noise was apparent, along with the cause...
I bought a pair of Meyle top mounts. I checked them a month or so ago just to be sure and they were dead centre.
Will have another look but I'd be very surprised if Meyle parts had failed that quickly..
still sitting dead centre..
When you find it, it shouldn't be too expensive then! :thumbsup: :thumbsup:
Hopefully not ;D
I've decided to go with and ordered front control arms with powerflex bushes pre-fitted. I know it will make it harsher.
I'm not at all convinced the noise is from the control arms but it's the only part of the front suspension I've not refreshed.
I tidied some bits up under the bonnet, like the loose battery cover and actually the valve I posted a pic of on Carreras thread, which was bashing on the inner arch and used to be wrapped in spongy stuff..
Hard to say from the description but I've known of cars with poly bushes that make lots of noise, especially over undulating bumps.
Hmm, lots of new bits.
Is it possible that the springs are going free when the strut is in full droop ?
Small little helper springs are available that will take up the slack
Quote from: carrera on 17 July 2020, 11:17:11 PM
Hmm, lots of new bits.
Is it possible that the springs are going free when the strut is in full droop ?
Small little helper springs are available that will take up the slack
Yes I'm terrible for replacing stuff that might be warn but probably isn't, in the hunt of a 'tighter' feel (so to speak :-[ ).. However I'm kind of with your thinking, especially with the shorter stroke b8, I think the strut is going to it's full extension over the bigger lumps, although I'm not sure the spring is going free - it certainly shouldn't be, it's matched to the damper!
I've been chucking it round quite a bit recently and apart from a fair amount of torque steer (the thinking behind the poly bushed control arms) the handling is spot on - esp on or off. For a big estate, it's a lot of fun..
As you say Audax - I guess it's part of the payoff and I need to accept that!
Here's a helper spring in case the main spring is going free
(https://i.ebayimg.com/images/g/t~IAAOSwxdxdAOrS/s-l1600.jpg)
The low tech alternative is to tie wrap the spring to the top or bottom plate.
If you want a tighter feel, stop playing around with Bilstein and get some proper gear.... you can just see the helper spring on the top of the Evo3 strut. Deeeeep pockets required though :)
http://www.proflexuk.com/products.html (http://www.proflexuk.com/products.html)
I've given the spring a good wiggle with the wheel off the ground and it's in no way free.
I the EVO3 might be a bit of a step to far for a road car :thumbsup:
I have often wondered how the high speed bump adjustment would cope with road humps on those struts. Admirably I think :)
So, that's that theory out of the window then, there isn't much left. Steering rack, ARB all properly secured, track rod ends in good condition, droplinks fine, even though they are new, bobbins for oil cooler intact ???
I've never investigated this for myself, but there have been some issues with engine sub-frame bushes where the big washers have been put on the wrong end.
Bit more potholed driving today and it is very noticeable.
I keep thinking it's maybe the poly ARB bushes squeaking (which they do a little and more so when wet.) but it's definitely more of a rattle - which I would have said was drop links but they're new genuine Saab jobs.
I'm convinced it's coming from the strut and have just come across a lot of post about Bilstein knock - which appears to be a fault with the strut in some cases. Never had a problem with them on the 9-3. I'll ask Joe to check the top nut is torqued up properly at least and get his opinion when he has it in August.
I do keep coming back to the control arms. My video doesn't show it too well but that fore/aft movement is a good half inch and without much effort.
Anyway I'm off to Devon tomorrow at 6am with the caravan so I'm going to have to live with it for the time being.. Wont be an issue on the motorway mind!
Quote from: sgould on 18 July 2020, 08:18:35 PM
I've never investigated this for myself, but there have been some issues with engine sub-frame bushes where the big washers have been put on the wrong end.
engine subframe bushes? You mean the front two on the subframe?
I'm 99% sure mine were fit with the washers on top between the bush and the body..
That didn't sound right to me, so I looked at EPC
Yes the engine subframe ones. Not like the originals. The poly bushes have different ones.
Although it's the rear ones that usually go first.
I agree the rear ones do usually go first..... needed to do them on the green car, and FKA has already had them done. From an engineering perspective isn't the design the same though, compliant material around a steel bush, clamped between two large metal surfaces (one of them a washer, on the underneath) ?
I'm not sure, to be honest. But in the way I pick up info from others, there was a thread where someone had wrong ly placed the washers on his poly bushes. He reckoned the instructions that came with them were poor.
I bought the none powerflex bushes from Bill. They had no instructions but everything I read stated the washers go between the top of the bush and the body.
Only question mark over any of the a available poly subframe bushes is they're all the same diameter, which doesn't account for the slightly larger middle (??) bushes..
Best ask Bill then.
I would have expected the pliable bit of the bush to be clamped between two solid surfaces....... a washer on the bottom as for the OE parts and either a washer on the top, or the subframe itself.
The thread on uksaabs has posts from a few different people stating the washer goes between the bush and the body. Eurosaab USA video states the same but actually shows the fitted incorrectly ;D
I'm fairly sure I asked Bill at the time and got the same answer..
Seems like I was right and wrong at the same time having looked around :)
The bush is clamped between two washers.... the original one on the bottom, the one supplied with the bushes on top between the bush and the subframe.
Best I can do on my back in a field but the front two are correct, no reason to think the other 4 would be wrong. I don't think the problem is subframe bushes.
Talking of fields - I can definitely feel a bit of a clunk driving on and off the lump field. I'm still swinging towards the control arms because I can't see what else it could be!
As I happened to have a torque wrench with me .. None of the 6 bolts were at 100NM, some less so than others but only a half turn or so off. I've taken them up to 100NM +45deg. Had a quick run around the field and couldn't hear/feel anything but that's not really much of a test. Will be driving again tomorrow but now I'm off to the beach for a swim :thumbsup:
I typed this while you were posting, so I'll leave it for consideration if you haven't cured it...
Are you 100% sure that the noise is from the front? I had a really awful banging sound that I finally traced to the rear anti-roll bar. It was just the U shaped clamp over the bush that was moving imperceptibly. The hooked in end. I only traced it when the shock absorber was off the car and moving the ARB gave a small click. I suppose the front bar is held in the same way?
The tracing was done by ear and feel, and pinpointed by the small dribble of fresh orange rust.
Possibles from me if it wasn't the subframe
- did you replace the soft metal spacers when you did the springs?
- how are the rear trailing arm bushes?
I replaced everything on the front struts and the rear trailing arm bushes are powerflex fit by the PO.
I "think" I may have lost a clunk since tightening the subframe bolts but the rattle is still there. Think as the roads here are quite good ..
Seems to be in time with the front wheels going over rough road so inclined to stick with it being front end. I don't have the wherewithal to check the top nut on the struts but will ask Joe to check when he has it.
If the subframe bolts have worked loose (time will tell) other than locktite, is it usual practice to replace them as they're stretch bolts?
I'd bought the complete front control arms that come with Poweflex bushes pre-fit. Worked out a little dearer than just buying the bushes but potentially cheaper than the paying the labour on removing the old bushes. They went on the car last week [along with a Jetex (Simons) CAT back which looks kinda smart, sounds lovely at idle and overrun, and isn't in any way intrusive on the motorway..]
Steering is much more direct, torque steer is reduced and it seems to get the power down a lot better pulling out of bends. Doesn't feel any harsher over the potholes, just more solid. More than happy with this month's unnecessary expenditure ;D
The rattle however is still evident, not too surprisingly.
Joe checked over the front struts and can't find anything but can hear the rattle, although as he said, it seems like quite a light metallic noise.
I think I may have found it. I'd adjusted the bonnet a few months back as the shut line wasn't even (slightly up at the front). I've put the stops and the latches back where they were and although there's still a slight rattle on some of the larger bumps, it's nowhere near as bad. I can only assume that's why the bonnet had been set like that in the first place...
Exhaust porn :D
So the rattle is not related to the bonnet.
Had a poke around again today and noticed that the offside top mount is squeaking and has started to sit a little off centre. I think it's failed/failing.
Really annoying - it's a Meyle part and I really didn't expect it to to fail!
Clip below is with me bouncing up and down on the drivers door sill - definitely the mount. Jacked the car up and shook the strut and it makes the same noise. Also had my ear to the top mount whist SWMBO bounced on the car :o ..
https://www.dropbox.com/s/m3hhmnxkktzac4y/2020-08-14%2016.10.10.mp4?dl=0 (https://www.dropbox.com/s/m3hhmnxkktzac4y/2020-08-14%2016.10.10.mp4?dl=0)
Hmmm...... I thought it was top mounts, but you mentioned they were Meyle so I thought, doubt it's those then ::)
I wonder if the top nut was done up too fiercely with a gun, rather than with a hand torque wrench.
I think my failed top mounts were faulty. They were cheap and the rubber had come away from the metal with no sign of there ever having been any bonding.
Quote from: sgould on 15 August 2020, 12:05:37 AM
I wonder if the top nut was done up too fiercely with a gun, rather than with a hand torque wrench.
This thought has crossed my mind but I doubt it and no way to know either way.
Two other possibilities. I bought it from relatively small parts supplier, has a website but sold on ebay, was the only pair they had and they don't seem to stock any Meyle parts on their site. So possibly a duff part? Secondly there are a number of posts on other car forums complaining about Meyle front and rear top mounts failing or having knocking issues, the latter specifically when combined with B8s.
Anyway, I've ordered a set of genuine Saab mounts from Bill (which I should have done in the first place!).. and I'm considering fitting them myself.
Off with the caravan again tomorrow for a few weeks so they'd better hold up. At least most of the weight is on the rear :-\