slight knock on braking

[marinaman]

Hi all

When i come to set off an dhold on the footbrake as soon as i release and re apply very gently there is a very slight knock, like tapping on a window sound, seem to have it also now and again as the car goes over some surfaces as well.,  as there seems to be a vast amount more bushes and links under there compared even to a heavy car like the Sharan we had. this as you all know is in a different league
Any ideas as to which may be the culprit with symtoms described, have located only one slight bit of movement in drivers side track control arm at bottom which is felt and seen when grasping wheel at 9 and 3 and moving.
Thanks

[X5-D-Sport]

The Front End of these machines can hide a multitude of sins, slop & slack joints.
It is not unusual that an X5 can pass an MOT with drastic issues with suspension joints at the front.

Take it as gospel truth, that if you can jack the vehicle & find slop by hand, then it will be 10 times worse when you pull it to bits.

The design & set up keeps all the joints pulled tight, making issues difficult to detect easily, but rutty roads & pot-holes will show up the failed parts as a judder or shake thru the steering & the noise when you clout a pot-hole.

[themoog]

Agreed. Mine has horrific steering wheel shake when braking at anything over 40. There are only two parts left to replace - track arms/ends and if that doesn't cure it, discs. I don't normally get above 40 where I drive but recently I have been doing longer trips and its become more apparent.

[marinaman]

wonder then if may as well replace all, there is a kit on Ebay for £130 with every joint and link bar for the front included,  it seemed cheap compared to the seperate prices of each bar but wondered about the quality.

see here
http://www.ebay.co.uk/itm/SUSPENSION-TR ... Sw5VFWO~Jd

there are other full sets on for nearly £500  makes you wonder

[Greydog]

The X5 bushes have a hard life and generally are toast at about 80k. I used Ebay sourced kits front and rear over 2 years ago with a little (well quite a lot) muscle supplied by my sons we changed front and rear set ups completely. The worst job is changing the front lower ball joint in the hub they are a true Beeech of a job. Everything else is straight forward, a tip make sure you have the front suspension under load (on ramps in my case). If you tighten up the main brake reaction arm bush with the suspension extended when you put it down the bush will be twisted and it will fail early. Guess how I know that !! All done and 4 wheel aligned over 2 years and no odd tyre wear knocks or rattles and handling is great.

[marinaman]

Thanks for the advice,  the knocking seems to come and go at moment and hard to pinpoint,  just been out and sounded more like exhaust knocking under floor.  when i go over speed bumps everything is silent, front and back,, very hard to track down.

[X5-D-Sport]

I fitted that same kit to mine, cured every clonk on the front end in one go....
Expect to spend a long afternoon/day working under the vehicle... but it is so worth doing.
Almost like driving a new car afterwards.
Make sure you have 2 "Substantial" axle stands & a good trolley jack to ease bits into place by applying pressure here n there...

[marinaman]

Thanks for that, will have to wait for the weather as im a roadside mechanic these days, sad we have a small hotel with no parking.
are there any methods you found best to do, usually after doing one side you find it easier on the other after you have made the mistakes,  any sequence, or just unbolt everything and replace in the best way possible.
Is it best to rest on the stands rather than just trolley jack, read somewhere about needing the weight on the suspension to nip some joints up.

Thanks

[ianst0028]

always put it on axle stands when the wheels are off ..... if your under it and the trolley jack gives way it'll be messy and if you do survive youll be upset at having to replace your freshly bent discs
id recommend getting a decent (bloody huge) hammer for the ball joints in the hub and take the hub off the car to remove them (heat also helps but mind the abs sensor)
do everything up then do the final tightening with the wheels on and the car on the ground
once youve finished swearing and cursing at your beloved car get the tracking done (especially if youve replaced the trackrods and ends)

[ianst0028]

also should add spray all the bolts with wd40 or such like for a couple of days before you start the job (unless you have a good impact gun in which case make sure your batteries are charged)
and get new hub nuts for the drive shafts the old ones will be knackered after you take them off to remove the hub 

[X5-D-Sport]

Re WD40 treatment for a week prior to starting is a MUST do...

The Axle stands are a MUST also.... you will not survive long enough to squeal if one of these cars drops on your ribs or head....

Re order of doing stuff.... some bits may be easier to do with the car on its wheels, such as loosening ball joints if you can access them... the vehicle weight will secure the ball most often & allow some bolts to ease off easier.
Anti roll bat joints may well be easier on ramps...

Then roll off the ramps, jack & secure with axle stands & pull it to bits a piece at a time.

Personally, I like to do the matching parts each side as I go to make sure all the bolts are done up tight.

[ianst0028]

I've just looked at your ebay link .... the kit doesnt include the inner tie rods
my track rods were seized onto the inner ones and i ended up having to replace it all

you might be lucky 

[graemeX5]

Also it's worth trying something called plusgas.

Its a releasing agent and ten times better than wd40 and is great to soak sticking nuts and bolts in then go back in an hour aor so or overnight first and and hey presto

Graeme

[marinaman]

Many thanks for help all

[Upex]

I had a similar knock, only now and again, and only when breaking or turning. Turned out to be the big bash plate bolts. 1 was finger lose spinning, when tightenEd back up, solid as a rock and no more knock (I know they should be replaced, but tightening it up was all I could do then and there, and it solved the nick, so left it alone now)