Some diagrams of the system, so you can see where the noise is coming from: BWI ASBS

Similar to PDCC in the Cayenne (although they don't appear to source the whole system from one supplier).

Thanks Trommel, I had the car inspected today at the dealers and they found play in some bushes so it has been booked in to have these plus a revised or updated ARC, They didn't give much info but seemed positive that what they planned to replace would solve the issue.

Make sure they are replacing the valve block with the latest one with the dampers. Just replacing the ARC bar or any other suspension component will make no difference, the knocking will come back after a few hundred miles.

They always seem positive it will fix it. What else would they say?

Thank you I will call and ask tomorrow.

5.0 - hi, interested to hear whether the fixes are working. I have just taken delivery of a petrol Autobiography and, after about 350 miles, now, I can start to feel and hear the knocking that's been described in this thread...irritating!

Any news/guidance gratefully received, thanks.

400 miles on from the last fix and all is still well. Have just done a 240 mile drive to Devon and the car was super smooth on all surfaces. Pleased that I also got 24mpg average in spite of moving quite briskly

5.0, this is so far so good...'super smooth on all surfaces'..wow, fingers crossed.

So on this particular fix were all the parts on your initial post actually changed?

Valve block with dampers yes, updated software yes, was another ARC bar plus link rods and air springs fitted?

I ask because my dealer has the new valve block with dampers on back order. If you had all the parts fitted in addition to the new valve block, should I insist on the same in order to make sure of success?

If the improvement is down solely to valve block and software, then that is good news and economic sense.

Doodle, the new valve block and software is what makes the difference. I did have all the other things done as well as they were part of other TSBs so as they were taking it to bits anyway I thought I may as well have all the latest bits put on in one shot rather than decide later it needed them and have to take it apart again.

I have returned from my holiday and all is well with the latest ARC updates .

I have done my first long journeys in the car over the last couple of weeks and I am very impressed now everything is working properly. The car is epic for long motorway journeys. My old 2010 S/C was very good as well but the L405 feels much more comfortable at high speeds. Particularly when you need to slow down quickly it sheds speed effortlessly where the L322 always felt like you were trying to stop something very heavy indeed. Fuel consumption is very good, I did Salcombe to West London in just over 3 hours and averaged 25mpg. My 2010 would have done 18mpg on the same journey at the same speed.

The great thing is that when you get to the countryside and off the motorway the L405 is a joy to drive fast on twisty lanes. I never used to bother driving the L322 fast in anything other than a straight line as it just wasn't pleasurable for me or my passengers.

My MY14.5 Vogue S/C went in for the knocking today. Lets see what LR say.

Update: The dealer are following Land Rover's technical bulletin for handling "front suspension knocking sound" and will start with replacing the lower control arm bushes. I think this might take a while...

Pieter, maybe you should point them to the forum and read this post. Would be worth as they wouldn't have to waste time bringing your car in again and again But then main dealers don't like efficiency for some reason that I fail to grasp. MY 2010 5.0 SC Galway green and sand interior!!
Have the Faultmate MSV2 Extreme to be tinkering with the settings etc. !!

Car went to Dealers today for suspension mods after showing the dealer this post in the forum,
They were supposed to be having the parts to update but apparently Land Rover have now told them there
is currently no fix and no updated valve?, just wonder if there are only a few of these updated parts around
and only going to some of the dealers,
not a happy chappy as I have been living with this knocking for the last 7 months now hoping for a solution sooner
rather than later...
Would be interesting to know which dealers are currently getting the parts for this mod....

Chris

Mine went in last week for investigation! Told needed updated part, the dealer had the TSB attached to work card, told me part available for today and car going in tomrw for remidial work, asked to keep it for two days. Strange thing, when drove it away and upto Scotland... No knocking and transformed ride! Although has reverted today!!

My car was in for a complete "anti-roll bar assembly replacement" on 24/04/2014 (4th warranty visit). It came out transformed and I was happy for about six weeks before the noise started to creep back in. At the dealers on Thursday (7th warranty visit) and they were authorised by JLR to replace the front suspension "bushes". Last replaced on 06/01/2014 (2nd warranty visit). Car delivered back to house by dealer. A courtesy, or just because as soon as I drove the car there is clearly no improvement. Back to the dealer next week for this defect of design which they appear clearly no nearer resolving. "Not fit for purpose" springs to mind. FFRR user since 1974. RR No. 10 (2021MY P525 delivered Nov 2020)

have them replace the valve block... L/R dealers have a TSB to replace with 'new design' valve block, mine was done, as well as couple of mates and so far (touch wood) all ok....