Done loads of reading so apologise if the info is already on here.

I have an annoying, what only can be described as a shoogle, like a rear shock is knackered and not damping properly when going over an undulations on the road. If only 2 wheels hitting the undulation moving the car left and right it shoogles like its under damped. (difficult to describe)

The more I read the more pops up with all manner of possible issues including the ARC/ACE system

Looking for a replacement shock I see they come described as with CVD and without CVD. What is CVD? I am guessing its the ARC/ACE system equipped car?

Car seems a wee bit tail happy going round left hand bends so guessing (not had it on my ramp yet) that the right rear shock is the culprit. X5 40d

CVD is constant variable dampers. It means the dampers are controlled by a controller that signals to the dampers to adjust their damping behaviour depending on the terrain/road conditions/driving style.

Have a look at the top of your strut assemblies under the bonnet. If you have an electrical connector, you have CVD.

As you have an SDV8 with ACE(old term)/Dynamic Response you will most likely have CVD. Kev

2014 L405 RR Vogue SE 4.4 SDV8 in Corris Grey
2010 L320 RRS HSE 3.0 TDV6 in Stornoway Grey

Thanks for that. Most informative X5 40d

Rear CVDs have an extra oil chamber attached to the lower part of the shock, facing inwards. Check that both are still attached as they can get knocked off if they've hit something. If one is missing then that shock won't have any oil left so will be totally useless.

Thanks for that. Should be an easy enough check. X5 40d

knwatkins, you were correct  X5 40d

Believe it or not, the oil reservoir canister is actually glued to the shock not welded, go over a bad pot hole and the sudden increase in pressure can just pop the reservoir off...!!! Pete
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2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand Sold
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Sold
2002 L322 Vogue 4.4 V8 Epson Green (Fatty Offroader) Sold
-Click for Project Fatty off roader-

I note you're from Scotland and thus more rust! Ive changed quite a lot of rear dampers with rot holes in the shocker reservoir... Quite normal...

Thanks lads, seems a very poor design.

What's the score if aftermarket shocks, anyone used them?

Aerosus is one company that keeps popping up. 2 for £450 with 2 year warranty. There are cheaper at around £350 for rears X5 40d