C5x7 extreme tyre wear at rear

[Ceenine]

My camber appears to have increased. It looks way out. Can you tell me what the correct tolerances are please.

[Paul-R]

See post 2 of this thread.

[Ceenine]

Thanks Paul, brain and eyesight now in play. All I need to do now is to do some basic measuring.
Don

[aerodynamica]

Hi, I'm revisiting this thread because my rear tyres are so badly worn that they're in danger of failure. It is booked in to get 2x tyres but I really would like to fix this bad camber problem.
Svod. Do you still have your modified rods available?

I assume the reason the camber goes so bad is that all the rubber bushes have compressed and the lower ones stretched and that it all adds up. But I'm concerned that you changed them all and it still had bad camber.

[Svod]

Hi, I still have few of them. I'll contact you by PM

[aerodynamica]

Returned this evening with new rear tyres but the fitter warned that they'll not last due to the crazy camber.

I'm looking at replacing the upper suspension arm. I just removed a rear wheel to look at the access to the fixings screws. They seem reachable but I'm concerned about the condition of them and whether the ones that screw into the alloy hub upright and the subframe will actually come out.
The torx head screws are rusty and there's no way they'll take the fitting of a torx bit.

Anyone know the technical reason these screws have such a large flange head?

Most worried about screw no. 16 in this drawing, there's nothing to grip by the look of it.

Also screws 15, 16 & 17.

Are these screws available to buy ? I think some will be destroyed on removal attempt.

Any help greatly received.

[aerodynamica]

Now I think of it, probably the reason the screws have a large flange is to prevent any rod detaching if the rubber fails.

I found there is a lot of free play at both ends of this rod

So regardless of the upper arm, this one will need to be changed.

Just realised the one circled is no. 16 screw that does have more than just a button head screw as it looked in the drawing.

[aerodynamica]

Anyone know where I could get these screws? I never contact citroen dealers but perhaps that is the only source for these.

[aerodynamica]

Found a part number for screw 16! 5132 78. 3 per side. Need 3x of screw 17, 1x of 18, 5 of nut 71. For one side to change everything.

[aerodynamica]

Found them:
16 - 5132 78
17 - 5132 80
18 - 5132 79
71 - 6936 65

[Svod]

I’d definitely recommend replacing them—they tend to break.

[KennyW]

Graeme,

Item no 8 on the drawings is an adjustable tracking arm, but prone to rust together will need replaced. This will sort your camber problem.

Had this problem on my C5.

Kenny

Further on that arm are tiny screws which are supposed to be slackened to make the adjustments, these are usually rusted together and fall apart when a screwdriver is applied to them.
Did the tyre fitter not mention this arm (No 8) as the my local company did and said this is where they make the adjustments
I hope this helps you

[aerodynamica]

Graeme,

Item no 8 on the drawings is an adjustable tracking arm, but prone to rust together will need replaced. This will sort your camber problem.

Had this problem on my C5.

Kenny

Further on that arm are tiny screws which are supposed to be slackened to make the adjustments, these are usually rusted together and fall apart when a screwdriver is applied to them.
Did the tyre fitter not mention this arm (No 8) as the my local company did and said this is where they make the adjustments
I hope this helps you

Hi Kenny, yes I have this adjustable rod pair on order. Also have a pair of item no. 3 because I found the bushing at the hub carrier was shot (turns out this is what's letting the hub move the most). I also will replace item no. 2 but I'm going to fit Svod's modified version.
I checked the rear wheel alignment last night and it's way out. If it's supposed to be 0° 30' , it measured at -1° '20 .... no wonder the tyres were getting chewed. So these rods and rubber bushings are totally shot. The handling is terrible too at the rear where it feels like it 'tramlines' at the slightest bump.

I would like to replace these bolts but couldn't find them. They're all M12x1.25 so I could probably source them non- dealer.

[aerodynamica]

I have changed the control rods no. 3 and no.8 and found an initial improvement. The rearmost control arm was remaining as I was waiting on delivery of special adjustable rods made by a guy in Czechia, to fit to this position. These arrived and allow adjustment of the length of the arm no. 2. That allows the camber to be altered. I've set these lengths to the same length at the standard non adjustable arms. 440mm. The replacement rods no.8 in the diagram, were pre set to the correct length, 277mm, and that allowed them to fit straight on. Checked the tracking of the rear wheels with the track ace and they were toe out by -0° 15' which is an improvement on the -1° 30' toe out they were to begin with. I adjusted the rods to set it to 0° while waiting on the adjustable no.2 arms to arrive.. with these fitted now, at their stock length of 440mm the rear tracking was then measured at -0° 30' so, tow out a bit again but this was expected because the old no.2 arms had rubber bushings that were quite saggy, the mild toeout isn't too bad. I went for a spin, returned checked the rear tracking and it was similar. I shortened the front rods, no. 8, by one face of the hex to toe in slightly and rechecked on the track ace to find the reading was exactly the same! -0° 30'. So I guess that was too small an adjustment and I ran out of time and my little gas heater for the garage ran out of gas so it was time to call it a day! I think it's all a lot better. The rear wheels are visibly less cambered now although checking their angle off vertical with a spirit level shows they're still cambered too much. The short drive shows a marked improvement in the road feel although the steering wheel is now a bit off straight when travelling straight. I suppose I had adjusted the front tracking while the rear was wayward and now it's off because the rear is more symmetrical... I'll fix the front tracking after fitting the new front control arms I have waiting. The rearmost rubber bush of the arms is shot despite me only changing it 3 years ago. This time I just ordered a full replacement arm with the bushes already fitted.
But for the rear, see the photo of Svod's excellent adjustable rods

Meticulously adjusted to be 440mm circle to circle.

Fitted:

I'll leave the lot to settle in place and recheck the tracking after some time. If I'm going to adjust the rear arm length to reduce the camber further, I suppose that must be done first then readjust the tracking as the tracking will change (go further toe out) if the rear rods are shortened to reduce camber. But with time it should adjust well. I have not changed the upper arms No. 1 yet but likely will do in the near future. So, lots of bits done and an OK improvement. Have to revisit this soon.

[KennyW]

Graeme,
Wish I knew you were needing Item No 2 has I have a pair brand new in box QH make, obviously non adjustable.

I would take the car to a good independent tyre specialist who has a 4 wheel tracker and suspension system. I'm fortunate have a good one in the next village.I would get a print out everytime I had the car on the system.

Hope that's it sorted..

Kenny