MK3 rear suspension bump steering help!

[kaspian]

Went out last night on a cross country drive on twisty B roads for the first time since buying and came across what I could only describe as the back suspension steering this way and that when loaded on a bend if you hit any kind of bump or series of bumps.
I had experienced this 'shimmy' from the minute we picked up the car from new but this was when hitting bumps on A roads a couple of times on the way home . Last night this was only at 40-50 mph and does feel as though there is too much compliance in the bushes at the back allowing the track to go out and effectively steer from the rear.
Has anyone else experienced this effect or is it just a sign of a poor suspension design ? I suppose this could also partly explain strange tyre wear seen on some new shape Berlingos? PS car has all the rattles that everyone else seems to comment on -as if something is loose underneath or poor isolation of suspension from car body. I know its no sports car but the last time I experienced this sort of car handling was 30 odd years ago with rear wheel drive and knackered shockers!!!

[philip]

You get a shimmy from most cars with an axle beam at the back when going over a bump, i get it on mine as well as other cars i had with rear axle beams.
Regarding the noise from underneath the car it could be Link rods mine is going in tomorrow for an inspection.

see this link
http://www.berlingoforum.co.uk/showthread.php?tid=763

[Baldricks Pilot]

Thats an interesting one kaspian as I am aware of something like that having had mine for about a month now (XTR110, 33,000 miles). I am not sure I would identify it specifically as back end steering though but it does feel a bit weird. I have had two previous shape Multispace, both with beam axle and not had that kind of feeling. I had wondered about tyre pressures? Only joined the Forum recently hence the reply now.

[scotsron]

I had exact same experience last week, again twisty Highland hill road I use frequently ,road frost damaged and uneven - felt rear squirming side to side as i took bends - road bone dry but as I said very uneven.

[Baldricks Pilot]

I dont press on like a rally driver so when I have experienced this it is not at break neck speed. I had wondered if it was a characteristic of the tyres fitted? I shall check but I think that I have tyres on the back axle that are not identical ie; different tread and manufacturer.

[Baldricks Pilot]

By the way philip, the rear end of a new Berlingo is not a beam axle as such, being trailing arms from I believe a torsion bar as I cannot see shock absorbers when I have a quick shufty under the rear end. Will look closer. A beam axle has the wheels mounted on the ends of a beam and, as such are not independent in movement. The previous Berlingos also had the same arrangement.

[Baldricks Pilot]

No, not a torsion bar as it has standard shockers. I eventually got under and checked!!!

[Mart7792]

Hi,
hope this helps, i have experienced the exact same thing , when cornering and hitting bumps or uneven road the whole back end would skip sideways towards the outside of the corner. sometimes so much that a bit of opposite lock was required to correct it and i was not driving fast or like a rally driver. The old berlingos and partners (pre 2008) had independant rear suspension as such the training arms pivoted on the beam wich was connected to the chassis. so, if one wheel hits a bump the other wheel is unaffected. much better for handling and cornering. Unfortunatley citroen have gone cheap with the new berlingo and gone back in time with the suspension set up. the rear suspension is one complete solid beam. Both wheels are connected by this solid beam which pivots on bushes connected to the chassis. if one wheel hits a bump, that wheel has to move upwards to absorb the shock and because both wheels are connected by a solid great piece of steel the other wheel which is not going over a bump deflects upwards also. This causes the unpredictable sideways skip of the van under cornering on uneven roads. It cannot be cured. The whole setup of the rear suspension is cheap and a huge leap backwards in technology, but it will prevent the old problem of the trailing arm bearings failing. Me i prefer the old stup any day it trumps the new one hands down.
Thanks for readimng this if got this far.
Martin......unny: