C5X7 Ride Height

[mikez12]

Hi everyone,

I recently had to change the steering rack as per the usual reasons on a 2011 C5 2.0Hdi Exclusive 160 Hydractive suspension. I took out the front subframe to clean off the rust and re-paint it but during the process the mounting bracket for the ride height sensor got bent slightly from it's original angle so in a highly scientific manner I bent it back to roughly where I thought it should be.

After reassembly the ride height seemed slightly higher at the front than usual. I measured the distance from the front jacking points (on the sills) to the ground and it was 160mm. The same measurement at the rear was 140mm.

I have read the posts giving correct procedures for setting ride height etc but I don't have a lexia and even if I did I think it would to be quite difficult to accurately find the centre of the wheel and then accurately measure its height above a point on the subframe.

As a more simple solution i'm thinking that since I did not alter anything to do with the rear suspension, then the 140mm height from the rear jacking point to the ground must be correct and therefore I should adjust the front height down to 140mm also.

Does anyone know if those front and rear jacking points should both be at the same height above the ground, and if so is 140mm the correct height? I think the tyres are 225/55 R17 (will double check tomorrow) so if anybody has a similar vehicle I would be really grateful to know what the front and rear heights are on your car. I have attached a badly drawn diagram to try and show where I was measuring from.

Thanks very much,
Mike.

[GiveMeABreak]

The full procedure is here: The calculations are there because the values entered into the diagnostic tool get converted, so are not equivalent measurements, which is why it's a bit drawn out. But this is the only correct procedure. You could improvise on some of the tools though. Major adjustments are done using the mounting and the fine tuning on the diagnostic tool.

But if you are just after a ball part measurement, then I'm sure somebody may be able to confirm their rear height - but of course won't be 100% due to potential differences in wheels / tyres ground etc.

viewtopic.php?p=559127#p559127

But if it's not practical, then the dealer should easily be able to do this for you.

[mikez12]

Thanks for your help Marc and the link.

I could probably manage it by finding the centre of the wheel from the outside (where you can see the centre point of the little badge) then clamping a level piece of timber on to the wheel along the centre line, then taking a level from the end of the timber back under the subframe so I could then measure the distance from the subframe measuring point.

However at every part of that process there is potential to be out by a mm or two so by the time you get to the end of it the level of accuracy may well be questionable - add to that a concrete floor which although level is subject to slight bumps and hollows in the finished surface which adds another bit to the potential for error. Having said that I probably will go through the whole workshop manual process when I have a bit more time and better weather.

In the meantime I have now adjusted the front ride height down to 140mm clearance at the jacking points and I now have 140mm at all four jacking points.

I would be grateful to hear from anyone who could clarify the following questions or supply some measurements from their own cars which might confirm that I am at least in the right ball park.

Basically what I need to confirm is :-
(a) Am I correct to assume that the front and rear jacking points should both be at the same height above the ground at the normal ride height setting?
(b) If the answer to (a) is yes, then does 140mm clearance at those jacking points seem to be roughly around the same ball park as for other similar car owners here.?

Sorry for the long winded post and thank you very much to anyone who may be able to help.

Mike

[mikez12]

PS to Marc,

My local dealer charges Euro 27.50 for a bottle of LDS, so I am a little reluctant to enquire about how much they might charge to adjust the height settings!!!!

[GiveMeABreak]

They have the tools as they are used fo all other vehicles too, so shouldn't taken them that long, no more than 30 mins I would of thought