L405 2018 4.4
I have a noise that I cannot find the source of. I am a past technician and have my own small workshop including a 2 post ramp.
The noise is very difficult to describe, I often get a sort of gentle double clunk/thump from the rear when setting off for the first trip of the day, it is a soft thump, not rotational, I have now tuned into it and can hear it most of the time. You would think it is suspension related as it seems to correspond with the ride. It almost seems like a body panel type resonance if that makes sense?
I have;
eliminated the sway bar / ARB
eliminated the Rear shock absorbers
Transfer case double oil change and calibrate
Rear diff oil replaced (don't think its connected but was done as part of servicing)
Rear Brake pads / discs replaced (again, don't think its connected but was done as part of servicing)
All joints inspected
Thorough inspection of the underside / exhaust etc.
Rear tailgate adjusted
Inspected every item I can find that could possibly move like the spare wheel, jack etc

This really is driving me nuts! any ideas would be appreciated no matter how obscure they may be 2018 4.4 TDV8

If the rear diff is an e-diff, try recalibrating it.
My recently-acquired MY21.5 gives an initial thump or 2 so I'll be trying a recalibration. L405 D350 SE Carpathian Grey D5 19" rims

Isn't there a TSB relating to a thump sound from the fuel tank?

possibly this,


https://www.fullfatrr.com/gallery/albums/u...d%20~1.pdf ... - .- -.




Y. O. L. O.
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Thank you for your suggestions, the only option on the latest GAP tool is to self test the diff, which it passes. I don't believe it is the fuel tank problem, it is not affected by the amount of fuel, nor by accelerating / decelerating, side to side etc but more with suspension / body movement, on a smooth road it's OK, but more noticeable on a less 'smooth' surface 2018 4.4 TDV8

Is there a later rdcu s/w version? I read on another thread of such an update.

I feel that mine's e-diff is too aggressive, judging by the instrument cluster display of the extent of activation. eg gentle acceleration from very slow after turning a sharp corner, the rear e-diff is showing about 75% engaged up to 75 kph. L405 D350 SE Carpathian Grey D5 19" rims

According to the GAP tool, mine is on the latest version 2018 4.4 TDV8