Clunking Front Suspension

[M@tt 77]

I thought Id post this as Im determined to solve my clunking front suspension problem so Im going to document what I have/havent tried and hopefully resolve this.

 

The clunk sound appears when I come on/off the gas and I can feel it through the floor although exact location Im not sure.

 

As the car was pretty much rebuilt from scratch and its done less than 3k in mileage it has had

New grpn top and bottom engine mounts (not gearbox thats the original)

New drop links

New suspension rubber mounts and bearings

 

I have removed the drop links completely from the car and driven it and the clunking is still there so it's not those.

 

I have been round and checked all nuts and bolts and made sure everything is done up nice and tight with the exception of the gearbox mount and battery tray bolts - Ill check those tomorrow.

 

I found one of the subframe bolts was loose as it appears to have stripped the thread of the captive nut on inside of the car I am going to get a new nut tomorrow but Im not convince it is this as the other 3 are done up extremely tight and can't see the subframe being able to move at all.

 

I have checked the wishbone pin holes in the hubs and they do not appear to be ovalled at all. I have replaced the pinch bolts today with genuine Peugeot ones as I noticed that one of the bolts appeared not to be correct. It was a standard threaded bolt and looks like the threads have been crushed somewhat where the wishbone pin recess had been pushing on it. I thought perhaps the incorrect bolt would allow the wishbone ball joint to move up and down in the hole if the bolt was not correct but even after replacing the bolts the knocking was there. Could the groove in the wishbone pin have now become enlarged and therefore allow movement?

 

It's fairly obvious that the clunk occurs as the engine moves either coming on or off the gas or braking heavily so I had the thought that it could possibly be the manifold/downpipe join. I have a feeling that when we rewelded on the flange to the chopped downpipe to mate up with the exhaust manifold if you look at it from the side Ive got a feeling that the gap at the top wasnt the same as the gap on the bottom therefore I wonder whether when the engine moves when accelerating or coming off the gas it is moving sufficiently for the 2 surfaces of the flanges to be pushing against each other and causing a bang or causing it to travel through the engine and therefore felt in the car? So I am contemplating removing the exhaust briefly from the down pipe and try driving it without to see if that is it.

 

So list of jobs for tomorrow is

 

1. Check gearbox mount and battery tray bolts

2. Get new captive nut for subframe bolt

3. Remove exhaust and drive car briefly without it

Edited January 12, 2007 by M@tt

[Alastairh 47]

Tbh mate, as soon as i saw the title i thought sub frame bolts.

 

id do that first before anything and go from there, as you know theres an error there, so maybe it could be making you read too much into it.

 

Despite your engine mounts being new, have you inspected them? Also i presume you have a baker or equivilant bush on the bottom mount which would mean you've taken the bottom mount off, maybe just quickly double check all the 16mm bolts are super tight

 

Alastair

Edited January 12, 2007 by Alastairh

[pug_ham 242 3 Cars]

I had similar to this on my STDT for a while & it turned out to be the bolt that holds the balljoint in the hub was allowing it to move over bumps causing the knocking. Was really annoying & such a simple fix.

 

Were the genuine Peugeot bolts shouldered or threaded all the way? I always get new shouldered bolts M8 x 30 for the balljoints (for about 50p each) so there is minimal gap between the balljoint pin & bolt .

 

Another time with a similar noise was when I'd swapped an engine in a friends car & the backbox was hitting agaist the torsion bar when the engine moved as you went on or came off the power but that also happened occassionally at start up.

 

Is the downpipe hitting the bulkhead seam at all? Has it always happened since you finished the rebuild or only started to happen after a few K had been covered?

 

Graham.

[M@tt 77]

Were the genuine Peugeot bolts shouldered or threaded all the way?

They were shouldered for about an inch or so then threaded.

 

I'm fairly sure its done it since the start although its definately got worse as time has gone by so i think its something wearing/loose.

The only things i havent changed are the wishbones and the track rod ends as they all seemed fine when i rebuilt it. No obvious signs of wear and joints all nice and firm.

 

I had a look at the downpipe and there does seem to be plenty of space around the downpipe with regards to bulkhead and ARB so i'm not sure its that, although won't rule it out. I'm going to get Henry to sit on engine whilst i go back and forth tomorrow with the bonnet up to see if he can spot/feel what it is

 

QUESTION

Not having had a ball joint fail before what is it that exactly fails? is it that the recess in the pin that the bolt slides through becomes enlarged therefore allowing the pin to move up and down in the hub or is it that the joint becomes loose? and how loose is loose ie should you be able to move the pin by pushing round in a circle with just say your index finger? or should it be very stiff?

Edited January 12, 2007 by M@tt

[davev 1]

QUESTION

Not having had a ball joint fail before what is it that exactly fails? is it that the recess in the pin that the bolt slides through becomes enlarged therefore allowing the pin to move up and down in the hub or is it that the joint becomes loose? and how loose is loose ie should you be able to move the pin by pushing round in a circle with just say your index finger? or should it be very stiff?

 

usually if a ball joint fails u will have movement between the ball joint knuckle and the wishbone. bast checked by jacking up the car and checking for play in the tyre, by rocking it side to side and up and down(you might have spotted an mot inspector do it).

 

if you feel any play try getting someone the rock the wheel while you watch and feel the balljoint(squeese the rubber with your fingers and try to feel if the knuckle is moving apart)

 

p.s. if your going under the car make sure u support it with an axle stand(not saying you wouldnt do that anyway but its best i said)

 

dave.

Edited January 13, 2007 by davev

[M@tt 77]

right well i "think" i might know what it is

 

i went round and rechecked all the mounting bolts were done up nice and tight, some needed a bit of nipping up still but it still didn't cure the clunk. and in the process i managed to shear off 2 crappy bolts that i'd used in the battery tray so then had to fanny about drilling them out and fitting new ones

 

i then gave the drivers side driveshaft a good tugging about and found i could feel a small amount of movement if i tried to rotate the shaft forwards and backwards by hand. It would produce quite a faint clunk clunk noise as i tried to rotate it back and forth. It would move probably less than a mm at a guess however i imagine the torque the gearbox would be putting through it it would amplify this greatly and is therefore proabably producing the noise.

 

Therfore swapping a driveshaft i think is the next task although i've got a feeling i replaced one of them when i rebuilt it but it might have been the passenger side one. i tried the same back and forth rotating on the passenger side driveshaft and didn't experience this movement so hopefully its this

[M@tt 77]

after pushing it somemore i have found that i can also move the driveshaft left and right (ie towards wheel and back towards gearbox

) if i grab it and pull it.

 

The hub nut is torqued up nice and tight and i can't make the wheel move if i give it a good shake when its jacked up off the ground. Could the side to side movement indicate faulty wheel bearing? i had 2 new bearings put in but i was not 100% happy with the monkeys that did it, they seemed a little too rough for my liking putting the new ones in and so could potentiually have damaged one

Edited January 13, 2007 by M@tt

[Alastairh 47]

To test your wheel bearings:

 

Jack the car up, and push and pull the wheel at 12 and 6 o clock and see if theres any movement. Despite it being a loudish mi, can you hear any whining that changes pitch when you turn left or right at 30 mph?

 

But the drive shaft, sounds like its worth a swap to tick off the list, but im surprised your being able to pull the shaft away from the hub towards to the intermediate bearing, so maybe deffinatly worth a swap.

 

Alastair

[davev 1]

driveshafts will move in and out a bit as the bearings/cv joint will have to move when steering. its the free play in rotating that usually causes noise. although i have saw alot of driveshafts that have a bit of free play and are quite.

 

could try putting full lock on and pull off to see if it clicks constantly. usually does if cv joint is dead.

[pug_ham 242 3 Cars]

after pushing it somemore i have found that i can also move the driveshaft left and right (ie towards wheel and back towards gearbox

) if i grab it and pull it.

Thats normal imo, they won't be solid to allow for suspension movement.

 

You can check the balljoint without jacking the car, get a screwdriver between the wishbone & hub & try levering between the two. Any vertical movement shows play, just try to see if the pin is moving at the top of the hub or just the wishbone is moving independently.

 

Or remove the bolt, drop the wishbone out of the hub & see how easily the pin can be moved, if they are dead you can feel the movement easily. (jacked or on stands obviously)

 

Graham.

[Edp 67 3 Cars]

I agree with Graham, there should be some play in the driveshaft from side to side. If its a wheel bearing you should here a low rumbling noise when driving.