You have a good point there

colalowe wrote:

It does feel like the rear shocks work ok in reverse when they hit the bumps first and the ride is acceptable vs driving over front wheel s first when it just crashes over the bump. (there was just one or two bumps/imperfections on the road, if the whole road is bad then I don't think it will show because once the fronts hit the shocks all stiffen up)

If anyone gets a chance have ago and see if you get the same feeling if you reverse over the bumps (I did it around 5-10mph)
It could just be a placebo effect as I'm thinking now the front shock are the problem

This is interesting. If the working theory is correct in that the fronts are ‘fooling’ the rears to stiffen up, then yes it makes sense that the rears would be soft when reversing!?!?

I will give that a go at some point soon and will report back.

Also, yes the placebo affect could be a big factor!  Currently driving: 2012 L322 SE Overfinch 4.4 tdv8

Past rides:
2014 Audi Q7 3.0d (good riddance)
2010 L322 Autobiography 5.0 Supercharged
2011 L320 HSE 3.0 sdv6
2014 Jaguar XF-RS 5.0 supercharged
2007 BMW 535D
2005 Mini Cooper S

https://www.fullfatrr.com/forum/topic59478.html

I can’t wait for Sam to fit some new front shocks and hopefully solve the mystery  Gone to a good home: 2011 4.4 TDV8 Vogue SE Buckingham Blue with Ivory and clear glass = "Rory"
2025MY Defender D350 90 in Silicon Silver on coils
1974 Series 3 Lightweight = "Millie"
Many, many other Landies over the years
My preferred specialist: www.glenrands.co.uk
--------------------------------------------------

And this is what I don’t understand, or my logic is wrong….

If the fronts crash over a pot hole, should the rear not soften so you don’t feel it when the rears go over it… or at least feel it less?

And if it’s supposed to give best of both worlds, I would have thought the shocks only stiffen during cornering/acceleration/braking…. To combat the weight shift and resultant body roll….. as has been measured on the icarsoft previously.

Why are we thinking the fronts being stiff would force the rears to be stiffer than normal?

Do we think the ECU can determine between lateral forces with body roll and lateral forces with the body flat… ie shocks already stiff? Do we think that’s what it uses the height sensors for? Or is that bit used to determine if you are off roading and not muck about with the shocks?

Just thinking aloud…

 2011 Range Rover Vogue SE 4.4 TDV8

Previous cars :
2003 Range Rover Vogue TD6
1999 Discovery Td5 ES
1995 BMW M5 3.8 6 speed
1992 Range Rover 3.9 Efi Vogue
1992 BMW M5 3.8
1988 BMW 735i SE
1989 Ford Sierra XR4x4 2.9i
1981 Ford Fiesta Supersport

The shocks can change stiffness many times a second during compression based on individual wheel rate and extent of articulation as detected by analysing the signals from the CVD height sensors along with many other inputs such as vehicle speed, rate of acceleration in all directions then can change many times again during extension over the same bump.
Unfortunately I no longer have a copy of a LR engineering paper detailing CVD operation that I once had.

Where did you get the LR Engineering paper? And what happened to it? That'd likely be exactly what we need right now! Sam's Motor & Machine YouTube Channel: https://www.youtube.com/channel/UCgNSRjY0I9FCzsi9ku3ccbw

Home of the 'Cheapest 4.4 TDV8 Range Rover"

Sadly I don't feel I have an answer to the question/ theory of why a bad shock causes the system to flat out fail at doing its job but I am now fairly certain the answer lies in a faulty shock as opposed to a faulty sensor based upon mine and coopss experiences successfully resolving this issue.

There may be other L322s out there experiencing a hard ride caused by a failed rear shock absorber as opposed to front but I know ffrr lover replaced an obviously knackered rear shock with no improvement.

It will be interesting to see landymansams results of front shock replacement and perhaps ffrr lovers too.

In other news I've been Pming coopss to put a deal together on the rear shocks he's wanting to sell so will report back here once I have those fitted to let you all know if I feel its worth replacing the rears also.

I’ve also replaced a knackered rear shock and seen no change. Put 2 new Bilstein units on.

The system is obviously pretty clever….

I wonder if it is doing something with the rears, as it “thinks” the fronts are soft, as that’s the signal it’s sent to them, but it’s getting inputs it doesn’t expect, as the fronts are actually stiff as faulty….

Either way… as long as we find some sort of common solution, all will be good.

I’m guessing my fronts will be originals and done 96k.

 2011 Range Rover Vogue SE 4.4 TDV8

Previous cars :
2003 Range Rover Vogue TD6
1999 Discovery Td5 ES
1995 BMW M5 3.8 6 speed
1992 Range Rover 3.9 Efi Vogue
1992 BMW M5 3.8
1988 BMW 735i SE
1989 Ford Sierra XR4x4 2.9i
1981 Ford Fiesta Supersport

That’s great information, so I think my fronts are firmer than they should be and I guess the valve is not opening when demanded, so when they hit a bump the accelerometer senses a force greater than what it would normally be, this then stiffens the rear to prevent bounce or roll. This will then continue and cause the harsh ride.

But that’s all assumption and guess work as I’m no expert in these systems.

Do I believe the theory enough to shell out on a pair of new front shocks though, only to be bitterly disappointed if it isn’t the cure?

if you can get hold of a Icarsoft V2 you can monitor in Realtime the voltage and NM value of each damper.
in theory if you see the voltage drop, but the NM value does not it would indicate the valve on the damper may be stuck or the fluid in the damper has past its best or leaked away (you cannot detect a leak on the fronts unless you take the air bags off)

just a thought 2012 Vogue 4.4 TDV8 - Current
2014 Navara V6 - Gone
2004 Vogue TD6 - Gone
Grand Cherokee - Gone
Discovery V8 (LPG) - Gone
Discovery TD5 - Gone

Just to update

when i engage drive the shocks get a voltage of 1.5 volts this drops the NM value from 899NM to 250NM on the rears.
I will try to plug in and take some pics of all four to give people a baseline to work from. 2012 Vogue 4.4 TDV8 - Current
2014 Navara V6 - Gone
2004 Vogue TD6 - Gone
Grand Cherokee - Gone
Discovery V8 (LPG) - Gone
Discovery TD5 - Gone

There are a few icarsoft V2 on the bay of e, but I’m not sure if they all cover the same modules, some just say ABS, SRS etc… don’t want to look at one and then it not do it.

Does it get an actual NM reading or is it just calculated from the voltage? I thought communication to the damper was 1 way only?… could be wrong….

 2011 Range Rover Vogue SE 4.4 TDV8

Previous cars :
2003 Range Rover Vogue TD6
1999 Discovery Td5 ES
1995 BMW M5 3.8 6 speed
1992 Range Rover 3.9 Efi Vogue
1992 BMW M5 3.8
1988 BMW 735i SE
1989 Ford Sierra XR4x4 2.9i
1981 Ford Fiesta Supersport

I’m curious about that too… there are two wires to each strut so how does it supply both the volts/amps needed and get the NM value back?
I suspect it’s calculated as I see no way it can’t be.

Happy to be proven wrong.  Currently driving: 2012 L322 SE Overfinch 4.4 tdv8

Past rides:
2014 Audi Q7 3.0d (good riddance)
2010 L322 Autobiography 5.0 Supercharged
2011 L320 HSE 3.0 sdv6
2014 Jaguar XF-RS 5.0 supercharged
2007 BMW 535D
2005 Mini Cooper S

https://www.fullfatrr.com/forum/topic59478.html

MarianaWestminster wrote:

It will be interesting to see landymansams results of front shock replacement and perhaps ffrr lovers too.

It’s going to be a little while longer for me. My less than a year old Delphi control arms need replacing so will be putting in genuine like I should have done in the first place.  Currently driving: 2012 L322 SE Overfinch 4.4 tdv8

Past rides:
2014 Audi Q7 3.0d (good riddance)
2010 L322 Autobiography 5.0 Supercharged
2011 L320 HSE 3.0 sdv6
2014 Jaguar XF-RS 5.0 supercharged
2007 BMW 535D
2005 Mini Cooper S

https://www.fullfatrr.com/forum/topic59478.html