C5 X7/mk3 2.0 Hdi Exclusive: Tyre/transmission Noise

[mikevybiral]

Sounds like excessive tyre noise. Increases with road speed. Almost absent on new smooth road surface, extremely noisy on e.g. new tarmacadam (grit on tar). Doesn't vary with gear, steering from left to right and back, acceleration, braking. Sounds as though it's coming from front or f/o/s. Tried different tyres (Fulda > Michelin) - made no significant difference. Drive shafts probably worn but no sign of play. On an undulating road, the noise increases slightly (or maybe different noise) when the car moves up slightly on the suspension. Can feel more vibration than I would expect through my foot when pressed on floor next to clutch pedal. Sounds like a worn wheel bearing but the note doesn't change with direction or braking (as I would expect,) nor is there any play. It's like the vibration from the road surface is exciting a non-flimsy, non load-bearing component, but what could that be? Front struts are leaking slightly. Could it be o/s intermediate drive shaft bearing (but no play)?
Any other ideas?
It's really annoying and spoils an otherwise very smooth car!
Thanks fro your time.
Regards to all,
Mike
(2008, 160k, hydraulic suspension, saloon)

[Bick]

It could be many things like you say but to answer your question yes it could well be the inner bearing on the o/s driveshaft. Also the inboard c/v joints can go dry and cause the same kind of problem you have got.

Is there any way you can get the o/s up on an axle stand and run it up though the gears whilst listening. You could do the same with the n/s also. Remember if one of the front wheels are rotating and the other one is not (eg on the ground) the wheel that is turning will be turning a lot faster than the speedo suggests ( well thats what i was taught at college all those years ago)! Anyways what i mean is be very careful testing this way.

[mikevybiral]

Many thanks for your reply.
Will try your suggestion when I have a chance.
It's also been suggested it could be brake callipers.

[Stickyfinger]

My road noise reduced greatly after I found the lower joint had fallen apart.

[mikevybiral]

Thanks for this.
Do you happen to know which lower joint? I think there's quite some choice!
(My C5 tracking report is bang on for toe in and camber but slightly out, equally both sides, for castor).

[Stickyfinger]

http://www.frenchcarforum.co.uk/forum/v ... ower+joint

Also check the lower wishbone bushes as these are reported to fail quickly for some, I think these can give similar noise as a result

[Bob L'eponge]

After wheel bearings and the drive shafts have been eliminated as suspects, the lower joint that most likely to lead to a road noise, rather than a knocking on braking or turning, is the FRIP joint that secures the bottom of the hub. This is effectively a roller bearing (although it uses barrel-shaped rollers so as to be able to accommodate small variations in alignment) and so if it fails you will get excessive metal-on-metal play, which could conceivable 'rattle' around on rough surfaces. Most of the other joints, such as those in the lower suspension arms, are fitted with rubber bushes which are more likely to produce a clunk when worn, mainly on braking, accelerating or turning.

The lower FRIP joints usually - and apparently pretty commonly - fail due to water ingress. Main issue when changing them is that the inner race of the bearing will stay tightly fixed to the lower boss of the hub when you pull the joint apart. Because of this it is necessary to carefully prise the seal away from the body of the FRIP joint with a small screwdriver BEFORE the joint is separated, otherwise the inner race will pull through the lips of the seal destroying it. I'm not sure that the seal is available as a separate part. (The part shown in the Citroen documents - number 3623-26 - is a shield that presses into the hub casting itself, so providing a smooth running surface for the lips of the FRIP joint seal.)

If the joint is OK and could in theory be reused, but the seal is damaged and needs replacing (and is available...) then you would still need to get the inner race off the hub boss without damaging it. This requires the use of a bearing separator as there is no room to get the 'feet' of most arm type pullers under the race. (A small puller with thin or ground-down 'feet' might also work.) If the joint is scrap, then one way to get the inner race off (apparently, it is often very tight, if not seized to the hub boss) is to very carefully grind down one face of the race until it can be split.

Another issue is that the pressed-in stainless steel cover that the lips of the FRIP joint seal run against might be marked by any ham-fisted attempt to remove the inner race or any remaining parts of the seal. In either case the damaged surface would give a poor seal and would be likely to damage the lips of the new seal, so allowing water in and so necessitating repeating the whole job after a very short time. The answer is to pay close attention to the condition of the surface the seal will run against, polishing it up with a Dremell mop and some polishing compound, or replace the part.

It is easier to do all this if the hub is removed after splitting the upper ball joint that secures the top of the hub. (Something like a Facom U301 2-legged puller is perfect for this.) You might decide to change this top ball joint as well whilst everything is in bits, but to do this you need the right splined socket, which is much larger than the one used to do the lower ball joints on older Citroen models. If you can get one the genuine Citroen tool - Number 9780Q7 - would be best and these are also much better quality and (amazingly) cheaper than some of the aftermarket alternatives. (Of these the Sealey version is perhaps the best, but I think it only comes as a kit of 2 - Number SX-0271.) This joint need to to unpeened to remove it and peened on fitting, and I have read reports of the alloy thread in the strut stripping when the old, seized-in ball joint is removed, requiring the purchase of a whole new strut at around £200.

The Torx bolts the hold the FRIP joint in place need to be fitted with Locktite and torqued correctly - I have read some reports where these were done up with breaker bars and still came loose / were lost after a time!

This is not a difficult job for a competent DIY mechanic and given the faff potentially needed to do a really good job - as with polishing the surface of the hub that the seal of the lower bearing runs against, I can imagine that not all garages would do a better job than a DIY mechanic in any case.

[mikevybiral]

Is this the one?
http://i.ebayimg.com/00/s/MTIwNlgxNjAw/ ... d/$_57.JPG

[Bob L'eponge]

P.s. In the light of Stickyfinger's post it might be a good idea to get a genuine Citroen FRIP joint assembly so you can be certain of getting the best-sorted design variant. (I have just checked and some aftermarket suppliers actually charge more than Citroen.) Also, if it is not correctly pressed into place in the hub boss or is damaged, the guard (Number 3623-26) which provides a smooth surface for lips of the seal to turn against.

The genuine FRIP bearing is a special made by SKF for PSA, so if an aftermarket part carries the SKF markings and looks like the Citroen part (and is certainly NOT just a standard roller / ball bearing pushed into the housing as in the photo of the 407 part that Stickyfingers links to in his post) then it is almost certainly the same bearing as SKF supplies to Citroen. Obviously, checking this prior to purchase with an aftermarket part bought on-line might be difficult!

I have seen that some aftermarket suppliers claim that poor quality replacements can be identified by other design differences, such as a lack of the cross-shaped grooves cut across the bolt holes that are to be found in the original part. (And which supposedly are used to lock the arms of the FRIP joint into the proper orientation.)

The part I used was part of a kit carrying the Sidem brand name, and this both had the correct SKF bearing and a housing that looked identical to the original Citroen one in every way.

[Bob L'eponge]

PPs. A few more thoughts after looking through the links that Stickyfingers gave.

First off, it is clear that this design has been used for a while on PSA vehicles and that some important modifications have been done in that time. Hence, when looking at older threads what one sees may have little bearing on the design details of a later model.

After a bit of further research I have found that the FRIP joints used in the Peugeot 407, Citroen C5 and Citroen C6 have always used SKF's special self-aligning 'barrel roller' bearings, as show on the left in the image below. However, there are some other aftermarket bearing around that use standard ball or roller bearings, as pictured on the right in the image below. It appears that these have never been fitted by the factory and simply don't meet the specifications of the original.



The main modification that has been done with these 'FRIP' joints relates to the running surface for the seal. It seems that the older 407 design did not use a separate metal insert or 'shield', nor did the first Citroen C6 cars. The result was that any pitting or rusting of the surface of the hub would destroy the seal, so allowing water to enter and destroy the bearing. In turn the damaged surface would do the same to any new bearing / seal that was fitted. Here is a picture of a Peugeot 407, showing a particularly bad example of this problem.



I am almost certain that the C5 has always used the later design with the separate stainless-steel insert, which is pressed into the hub boss at the factory, so providing a smooth running surface for the lips of the FRIP joint seal. (In the photo it does look a little as though the shield has its own rubber lip, but this is just a trick of the light and that this 'shield' is all-metal, which makes sense given that its function is not to give any sort of extra seal but to provide a running surface for the lips of the seal proper.)



When I changed this bearing in my own 2009 C5 I didn't notice any separate shield, or an obvious joint-line between any insert and the hub casing. However, thinking back the total lack of corrosion in this area and the high sheen that appeared when I polished the area up leads me to believe that this shield was there, correctly pressed into place all the time, and when I thought that I was cleaning up the surface of the hub casting, it was actually the stainless-steel, pressed-in shield that I was polishing. On reflection, it would have been a relatively simple mistake to assume that this shield was not fitted and mistakenly try to fit a second one. Given that the bearing is designed to allow some vertical play, who knows, it might even have proved possible to reassemble the joint without noticing this error!

Of course, there is a possibility that some very early 'X7' C5's didn't have this separate shield / seal running surface fitted, but I can't see a note of such a change in the documentation.

If one were 'missing' on a car that had previously being messed around with by an incompetent garage, then it is possible it had simply been damaged / removed and then not refitted because getting a new one would have required making a special order. Without this seal running surface fitted, the bearing would probably not lasted very long at all due to water ingress past the lips of the seal and I notice that Stickyfingers, who said that this part was not fitted to his car, had already had new FRIP joints fitted twice in the past (at just 35 and 61k). Perhaps this is the reason why!

(I have just changed one of these on my car which has 180,000 km on it, and it actually wasn't in bad condition, with just a few water marks on the bearings. I only changed it because I had one 'in stock' after buying it a while ago in anticipation of having to do this job at some time, and I already had the suspension in bits because I needed to change the lower arms.)

[Bob L'eponge]

I see that SKF have a detailed technical guide to the 'CARB' bearings used in these FRIP joints. They are pretty sophisticated!

http://www.skf.com/binary/68-125948/6102_I_EN.pdf

Does anyone know the number of the seal used with these joints, just in case they can be sourced as a separate part? Knowing this might be useful if someone wanted to replace the seal and repack the joint on an otherwise sound bearing.

[mikevybiral]

Many thanks for excellent help thus far.
When the weather warms a little I reckon I need a diagnostic phase to eliminate some of: cv joint, intermediate drive shaft bearing, brake calliper, the range of bushes, lower swivel bearing, wheel bearing. Quite a list!
Mike

[Bob L'eponge]

Hope that you benefit from our experience when you do tackle the job!

By the way, as you probably know the C6 uses pretty much the same suspension set up, and looking on the C6 forum much the same issues have arisen with the C6 as well. It seems that, as with the first Peugeot 407 models, on the first C6 cars the FRIP joint seal did actually run directly against the hub, with pitting due to corrosion having the expected effect on the lips of the seal. Citroen then (around 2007) brought out a modified hub with the stainless steel insert. As the C5 came out a couple of years later than the C6 I think that the C5 benefited from this modification from the off, although I might be wrong.

Some C6 owners have also reported the effect of fitting really those cheap aftermarket FRIP joints without the high-tech SKF self-aligning bearing, as shown in my earlier post. The results were predictable with the now totally rigid lower joint groaning and over-stressing the whole system, and even triggering fault codes in the electronic suspension monitoring system. I can't imagine owning a C6 and then trying to save £20 by fitting some Chinese pattern part that in no way matched the specification of the original!

It might also be worth going for a part supplied directly by SKF, so by-passing the mark up made by Citroen and the after-market parts suppliers. The SKF part number for the lower joint is VKD 13501 (as ever, confirm the right part for your particular car before ordering) and this outfit (it is a mirror site of a German parts supplier, although I can't vouch for them as I have never used them) are offering them for under £38, plus shipping. That said, it seems that Citroen put a smaller mark up on this part than some of the after-market parts suppliers do, and my local Citroen parts counter is usually happy to give some discount.

http://www.bestpartstore.co.uk/17523

[AndrewH]

Thankyou Spongebob for this detailed analysis. I think I have the same problem - symptom is road noise especially at 70 or so on the open road. My C5 Tourer has done 138k miles and I suspected a wheel bearing.
My garage told me it was wonky tyres but I don't think so.

[melj]

Hi All,

I know this is an old post but as it was recently resurrected by AndrewH I might as well add my experiences here.

Like many others my first impressions of the C5 X7 Exclusive Tourer with 19" low profile alloys was that road noise was bad. I heard it clearly when I test drove the car with 90k miles on the clock, but having owned a Mk1 C5 for many years which was far quieter I assumed it was something mechanical that could be fixed. It sounded solidly mechanical like worn joints. But, despite having new front joints in all positions, including FRIP joints, I couldn't fix it. I was commuting to work 25 miles each way into Bristol along Somerset country roads and it was annoying the hell out of me. Eventually I spotted some Citroen 17" steel wheels for sale on Ebay complete with nice fat tyres so I bought them. Problem solved, the road noise was as good as any other car I have owned. The steel wheels with their plastic trims looked distinctly downmarket but I didn't care for my daily commute, it was bliss. I assumed that the fatter tyres had solved the problem. I could always fit the 19" alloys again if I needed to look cool again.

Eventually I spotted some 17" alloys with high profile tyres for sale on Ebay and bought them, thinking that they would restore the look of the car a bit and be just as quiet as the steels. They were not quiet, the noise was back as if it had never been away. OK, so it must be the tyres that made the difference so at the next tyre change I bought the same tyres that were fitted to the steel wheels but it made no difference - doh! I have stuck with the 17" alloys as they are not prone to catching the kerb like the 19" ones were. I used to dread going into the entrances/exits of tight multi-storey car parks as it was so difficult to keep the 19" alloys off the kerbs. The 17" alloys are fine as the rubber hits the kerb first. But the noise - arghhh!!!

Anyway, I can think of no reason why the C5 X7 is so noisy with alloy wheels fitted but the solution is clear - fit steel wheels, put on some sunglasses and loud music so that you can't see or hear passers by commenting on your lousy wheels.

Just relating my experience on the issue and presenting the solution that nobody will want to hear.

Cheers
Mel