Rigid front suspension C5 X7 3.0 V6 HDI

[silientshy]

Hello everyone,

VIN:VF7**************[VIN obfuscated, can be read by forum staff]
Just to note - my C5 have 19" wheels with 245/40 tires as per instruction.
When I bought this car ride was very smooth and gentle.

Recently I've noticed that front suspension is rigid and very sensitive. It happened gradually and today I'm felling like front is driving at highest position. I can reach all 4 positions so height correctors are fine (link could move more smoothly but it isn't bad - already purchased new correctors with links, I'm planning to check them on later date manually and eventually replace them).
Some more about this stiffness - even small bump on the road is uncomfortable to pass, rear is doing its best but I think that front shake is making it harder for rear to pass smoothly. Note that i can very easily tell if my wheel drove over horizontal signaling arrow on road. It's showing even more when I'm turning on intersection and the road where I'm going is slightly higher (approx 1-2 cm) - it feels awful.

I think that it is a symptom of used spheres. Front stud spheres are aftermarket as they don't have OE markings (don't know about others) on them and mileage written on them suggest that they were replaced on ~ 163000 km. (I already have ~ 219000 km) I think that 60k for aftermarket (especially when new ones can be under pressured already) is enough.

Things I've already done:
- Wheels are balanced and aligned, pressure in tires is monitored
- Suspension height is within norms
- I've vented LDS tank (without tank cap: highest position -> lowest position -> highest with turning wheels from lock to lock)

Things between upper and lower part:
- I've changed bushings of wishbone but I'm going to look at them as well and other mechanical parts of suspension

Things that I'm going to do:
- Depress suspension and check exactly level of fluid
- Calibrate heights of suspension and align axles once more

If nothing is going to show up I think that I'm going to buy from I.F.H.S:
- 2x C550FH
- 2x C550RH
- 1x C570FR
- 2x C552RR

And just pray that they will fix issue for sure.

Can I do something more? Any new information will help as I am desperate to bring that smooth ride back!

Thanks for reading that, I hope that you will have a nice day.

[GiveMeABreak]

I think you've pretty much done everything practical to check so assuming the spheres are aftermarket, you're probably doing the right thing changing them. Personally I would have fitted original spheres for longevity though.

[silientshy]

Personally I would also fit OE spheres as they have different internal structure to my knowledge. After rest of my checks I'm going to check with ASP if they could obtain new ones with OEM markings - but I've heard that they used later Eurorepar (PSA/Stellantis brand) which is rebranded I.F.H.S (Original Manufacturer). As people say Eurorepar had highest chance of getting exact pressure for new ones (probably stricter QC than I.F.H.S aftermarket).
With fast check of the web in my country I can get freely I.F.H.S sets, some Eurorepar (I'm going to check if I could make set out of these) and just two with OEM markings - maybe more if I dig deeper.

Of course there is option to get regenerated OE spheres but I don't know if I want to trust them...

[Kees]

Hai, for the center sphere in front, you can also put the 75 bar.
About the brand of the sphere's, i used also the ones from IHFS, because the originals are almost 3 times the price.
Greetings,
Kees.

[DHallworth]

My 3.0 HDi was very harsh at the front when I got it.

I removed the front spheres, pressure tested them both and found 1 was down on pressure and 1 was ruptured with no remaining pressure in it at all.

Replacing both got the ride much better. Make sure it's not riding too high at the front either as that'll have a huge effect on the ride. The little plates that bolt to the wishbone where the height sensor links attach get thin and crispy with age and weather and can bend causing the ride height not to be correct.

[silientshy]

Yeah, I know about them. The front is within spec, but the rear is a little bit off, as it looks like the rear left link is rusted, so there is a height difference between the two wheels on the axle. I've loosened it just for this week, as in the next week I will be going to my garage for service. LDS level is okay (no yellow tint, so spheres didn't puncture). As it was rainy this weekend, calibrating suspension wasn't possible due to that, and I've just noted that with rainy weather conditions (so there was some humidity/ dew), the ride was noticeably gentler, so maybe something is crispy?

This week, I will go to the vehicle inspection station to look at joints and bushings.

Either way, I will replace all links, to check the smoothness of all height sensors, and replace them if necessary. Meanwhile, I'm going to prepare some covers for links from dirt/dust/traffic (3d printed).
The struts are okay, with no noticeable leaks - just the cushion is aged, but it shouldn't make that much difference, even if the replacement of studs is so straightforward in this car that I can do it under the cloud without a garage.

I think I will grab a set of spheres and chisels for an impact hammer, just to be prepared for everything. First, change links with or without sensors and some mechanical parts. Drive it after, and if I'm not pleased with that, I will just replace the spheres.

[GolfMk1Vr6]

Any updates @silientshy?