[C5 X7] Strange intermittent 'knock' from front when going lock-to-lock.

[aerodynamica]

I had a steering clunk at low speeds that turned out to be the steering rack mountings were loose. The garage had not tightened them properly after the rack was changed. It was a clunk felt next to your left foot. Worth a thought. Can get someone to rock the steering while looking at the rack through the wheelarch. You'd need a deep socket to tighten them though because the nuts are recessed up in the front sub frame.

[KennyW]

Just had similar knock but I had the bottom axle bush nut and bolt I didn't tighten up to the torque setting. Tighten up no knocking.

Kenny

[MattBLancs]

I'm going to order a pair of 90° grease nipples and new FRIP.

Nippled FRIPs!

Close up

Probably next weekend job, weather and other stuff wanting doing dependent.

90° M6x1.0 grease nipples. Off eBay (and remarkably similar to the ones in a box set I'd forgotten included 90° variants that I came across again after the eBay order...)

[MattBLancs]

The new lower bushes I ordered were "arriving Saturday between 7:25 and 11:25AM" only they didn't!?

Hopefully tomorrow, or at least at some point this week please postie!

[the-termin8r]

Just want to post a quick update. I think I got the issue sorted, it was much, much, more terrifying than a ruined fripp joint. Took it to a place that is supposedly Citroen-authorised near me for this and a couple of other issues. Needless to say they were just as incompetent as all the other first-party ones I've been to and pretty much failed to reproduce and/or find any of what I told them about. Despite my detailed instructions and offer of being there with the mechanic during the test drive.

Anyway, I had them MOT it while it was there and that's when they found what we both assume is the cause of the knock and the vibrations I've been feeling above 85MPH. Turns out whoever last worked on the car somehow didn't thread the screw through the bottom end of the driver's-side strut and it was just flapping in the breeze. The garage said this was absolutely human error as the nut and bolt were there and so was the ARB drop link on the other end. And since the 'eyelet' on the strut was still intact there's no way it could have just popped or slid off the bolt. It just wasn't reassembled properly the last time it was worked on.

I've been driving like this for at least a year. The weirdest part is that I couldn't feel a single change in the driving characteristics of the car. Handling felt normal, ride quality felt normal, it was completely planted at speed as always. I have no idea how it didn't manifest itself as something other than the knock and slight vibration at high speed (which I chalked up to iffy wheel balance). My dad who was the owner of the car for 8 years before I took it off him couldn't feel anything either (he's driven it a few times since I became the owner). My only guess is that the strut was jammed between the bolt and the big vertical metal piece that the bolt is mounted onto and that was enough to give the same characteristics as if it had been mounted properly.




Now the most concerning thing is that last year I had a front wishbone and sub-assembly changed, but it was on the passenger side. Off the top of my head, the last time the driver's side was changed was 3 or 4 years ago. I highly doubt that car has been driven like this for 3 or 4 years while passing MOTs. But then again, it also passed last year with the apes I suspect broke it in the first place. The only reason I can see them disassembling that corner last year would be maybe as a reference for the other corner because they couldn't read the schematics or something, I don't know. My first thought when I got the news was to pursue this legally, but I honestly don't know if it's worth the faff or if I even have a leg to stand on given that I can't prove it concretely and it's been a year since the assumed wrong-doing. Anyway, I got the place that found it to check the other side and it was fine.

For anyone finding this in the future, if you hear a knock from the front, make sure your suspension is actually assembled properly.

[MattBLancs]

I'm amazed to be honest!

Markup

A = the nut that's supposed to hold the strut (anti roll bar drop link on other end of this)

B = driveshaft which it's can't have sat against in service (as would have worn a grove in it with the load it would have seen!)

Quite baffling!

Me, in May!!

Probably next weekend job, weather and other stuff wanting doing dependent.

Err that's tomorrow's job! Time flies, and other priorities overtook that job!

[the-termin8r]

I'm amazed to be honest!

Yeah, me too. All they had to do was replace the ARB drop link, strut was fine apparently. I'm just thankful it didn't let go at any point. I drove it up Snake Pass in the Peak District with my 4 closest friends in the car a couple of months ago. The amount of people that were unknowingly endangered over the last year is not something I want to think about.

[Stickyfinger]

Well that is a strange one....like Matt, I cannot see how this would not hit the drive shaft....and change the driving characteristics or ride height on that side..............very strange

[MattBLancs]

Just for completeness, FRIP with grease nipple installed today:

Described profusely here:
viewtopic.php?p=782201#p782201

[the-termin8r]

Here's a condensed version of a long-ish update I posted that got deleted with my account, but didn't come back with it.

Got the knock sorted, wasn't a fripp joint. Instead it was my front right strut not being attached at the bottom. The place I took it to somehow missed it when I asked them to look for the knock, but found it when doing the MOT (no idea what they were doing during the troubleshooting). They said the only way it could be in the condition they found it in was if a human hadn't reassembled it properly. I had taken it to a different place for a wishbone replacement a year prior. But they only worked on the left side of the car. I can only assume they disassembled the right as a reference guide and didn't reassemble it properly. That garage is the only one to have ever suspension work on the car. That means I've been driving around like this for a year. The even more terrifying option is that I've been driving around like this for 3-4 years because that's when the right was last replaced, but it hasn't been knocking for that long.

Pretty insane that the car felt completely fine to drive to me, my dad (who drove it for 8 years before me) and the mechanic. The only issues exhibited were the knock mentioned in the OP and some slight vibrations above 85 MPH which I assumed was just iffy wheel balance. I think I was able to drive it because the strut was likely wedged between the bolt it was supposed to be mounted on and the vertical metal piece through which the bolt is threaded.