Technical Clunk feeling from the front as I pull away?

[dac69er]

Doesn't do it every time which is a pain. Tends to be if I load everything up when I pull away, but again, not every time.

It just feels like something is shifting a bit as I move off.

I have replaced the entire front and rear suspension Over the summer. I asked the MOT tester to see if he could see anything and he had no luck.

If I go over harsh bumps, it all seems fine with no noises or anything. Only when pulling away do I get the issue. I'm not sure what to check????

Any ideas of something I could have missed?

 

[David C]

On my 899 Cinq, there was a gearbox mount on the left front that would work loose occasionally and allow the engine to rock.
When it came completely undone it would fall forward…

It was only held by a couple of M8 nuts & bolts.

Don’t know if the Sporting had a similar mount.

 

[dac69er]

I was thinking it was possibly the engine mounts, everything is tight though and I had filled them with polyurethane a couple of years ago.

The 899 engine has a different mount setup i believe but I will double check them though.

 

[dac69er]

Checked engine mounts, all fine. Got a small tweak on the front gearbox one, but that's it.

Double checked everything else and just about a turn on the drivers side balljoint nut, so I hope it's just that.
Must have needed a few miles to settle in since everything was replaced. Fingers crossed anyway!!!!

 

[dac69er]

Still does it

Thinking it may be the brakes perhaps? It's hard to fault find as I can't make it do it all the time, only now and then.

 

[David C]

Tricky without feeling/hearing it, but could be the pads shifting slightly.

I once had a slight clonk under my feet, which was the wishbone balljoint, fixed with a new wishbone. But you’ve replaced those, so hopefully not that.

 

[dac69er]

They are clean and free, so maybe once they get some crap and brake dust in them they will stop moving about. They don't have any anti rattle springs or anything, so could be as simple as that.

It doesn't really feed like a balljoint gone, it is very hard to explain and as it doesn't do it all the time, that doesn't help as others can drive it and have no issues.

 

[Ralf S.]

Driveshaft (inner CV joint/spider) might clunk.

They tend to make more noise when the suspension is extended, so uphill with a couple of concrete in the boot (if the car can do it) would reveal grumbling or rumbling.


Ralf S.

 

[dac69er]

I've had grumbly inner driveshaft joints go on one of my other cars and that just gave a vibration under light acceleration and a light grumble sound. They weren't even that bad.
For them to clonk they would have to be completely thrashed surely? There isn't any perceptible movement that I can feel either.

My dad suggested undoing all the suspension bolts and doing them back up.
He also mentioned the steering rack and the uj that connects the rack to the column. Worth a quick look I guess....

 

[dac69er]

Checked steering rack. Undone everything underneath, lubricated everything I could and retightened.

Went for a drive and initially it felt ok then all of a sudden started feeling like a balljoint was gone. This is probably the worst it has felt.

I guess it could be a balljoint, but i wound have expected them to last more than about 100 miles!!!!
The arms I removed had play in the balljoints and they were nothing like this!?

Any other suggestions?

 

[blu73]

100% certain its the front?? could it be the rear arm bushes? they are really hard to diagnose sometimes, knocking ones don't normally even come up on a MOT cause its hard to tell theres play there...

 

[dac69er]

100% certain its the front?? could it be the rear arm bushes? they are really hard to diagnose sometimes, knocking ones don't normally even come up on a MOT cause its hard to tell theres play there...

The rear was completely stripped and rebuilt. It has new poly bushes and new rear dampers.
I have double checked everything for tightness and it all seems fine.
I'm pretty sure it's from the front and you can feel it through the steering/pedals.

My dad suggested that it could just be the cheap front suspension arms have either the wrong taper on the pin so are not actually seating down 100%

I managed to get a quater turn extra out of one of them so need to give it a test to see if that solves it. If not I am tempted to just bite the bullet and buy some decent brand arms and see if it is just that as I am running out of ideas fast.

 

[blu73]

i think i'd be inclined to change the rear gearbox mount.. you said earlier in the post you checked the engine/gearbox mounts but i'm not exactly sure what checking them means... this does sound like classic rear box mount symptoms, just nipping the bolt up won't help and you can't really see it without dropping it off. Cost of a new one and ease of changing it i think its worth just replacing that first.

 

[dac69er]

i think i'd be inclined to change the rear gearbox mount.. you said earlier in the post you checked the engine/gearbox mounts but i'm not exactly sure what checking them means... this does sound like classic rear box mount symptoms, just nipping the bolt up won't help and you can't really see it without dropping it off. Cost of a new one and ease of changing it i think its worth just replacing that first.

i removed them and inpsected. i also jacked the car up in various places to check for movement.
if i drive along in first and keep flooring the throttle to make the engine swing back and forth i dont get any lumping or banging as though anything is moving about from that perspective.


the rear mount is about 18 months old and i filled it with polyuerethane, so its stiffer than normal. i would very much doubt it is that, but i agree, the cost for a replacement is minimal so it is somehting i could change.

 

[blu73]

its an interesting one to be fair, no knock with engine rocking, no knock from bump, only pulling away... mmmmm, i'll ponder this one a while longer but with all you've changed it is hard to think of anything else lol..

has it done it ever since you swapped everything or just something that came on after? stuff like this is so hard without experiencing it yourself first hand lol

 

[dac69er]

I know what you mean. And as it isn't consistent, it's hard to pinpoint. You can go for an hour's drive and it won't do it, I then pop down the road and it's doing it all the time!!!

It's only noticeably done it since changing everything, however last winter I'm sure it may have done it a couple of times when I was manoeuvring into a parking space, but I'm not convinced it was the same.

I may just have to put up with it until something falls off and then I will know what it is

 

[dac69er]

Well it is now a lot worse and I am still none the wiser as to what it Is!!!!

Kinda sounds and feels like an apple rattling about inside a plastic lunchbox. That is the best description I can give. If I go over big bumps it seems fine. It seems to be smaller suspension movements that cause the issue, but It is pretty much all the time now I am using the car properly.

It may be the front arb bushes perhaps? They are polyeurethane and i cleaned and regreased them.
think I will have to wait until something falls off before I know what it Is!?!?!?

 

[David C]

As a test you could take the arb off.

As you’ve removed it recently, the bolts should all be spanner friendly.

I ran my 899 Cinq with Sporting springs & dampers but no arb and it handled fine without it. So no danger there.

 

[dac69er]

As a test you could take the arb off.

As you’ve removed it recently, the bolts should all be spanner friendly.

I ran my 899 Cinq with Sporting springs & dampers but no arb and it handled fine without it. So no danger there.

I have done the before previously. It is less tight upfront, but fine to drive.

When I get a spare half hour when it's not raining I will whip it off to prove a point.

Hopefully it is just those bushes. I will just stick rubber ones back in if it is..

 

[dac69er]

It was the anti roll bar bushes.

I have now lubed them to death and refitted and Now i have 0 strange sounds or feeling from the front of the car. Feels as it should now