Originally Posted by TrioLRowner

Here is a picture of what Sarek is describing within the rear ediff, for those interested......... I do not know for certain if Magna is manufacturer which JLR uses; but, I expect they are.

https://www.magna.com/docs/default-s...rsn=6949b18f_2

Enjoy !!

Originally Posted by sarek

This type of bulletin brings me back to my dealership days. Under investigation....Change the oil 2x. . The differential in the rear locker equipped vehicles utilizes a torque on demand design. This uses a PWM drive motor and ball ramp with clutch packs. This design allows variable levels of locking requested by the ECU. There is a special type of friction modified synthetic fluid used in these type of torque on demand units to help promote friction for the clutches. Over time, these clutches and ball ramps wear and the clutch material contaminates the fluid. We have seen excessive wear of these units for no real reason. Fluid type and quality is crucial for these units. Non locking rear diff equipped units are just a conventional differential with not much service or complex components.

Originally Posted by Ericlockheed

Is this why you have been messing arnd with arb lockers?

Originally Posted by Gullywasher

My P400 2022 110 SE had the clunk complaint as above, but was not in the group of Vin numbers for the service bulletin. I did convince the dealership to do the transmission flush procedure and it did help. There is no more clunk. I had this done before 50,000 miles, so they did it as warranty work as they should. I felt pretty strongly that they should address this.

Originally Posted by mrmihai

I recently passed 50k miles on my 110 P300 and had the transfer case and center+rear diff oils changed (oils were dirty and cloudy already). Shortly after leaving the service shop I noticed a low thud/clunk noise coming from the rear/center of the vehicle, exactly where the rear-diff is. It is not a repeating thud and now happens rarely when pulling away at slow speed but is more likely to happen after a cold start. I can't seem to reproduce the sound on my own (manual gear selection, different stop/start behavior, etc.) and there is no CEL or code being thrown.

I took it back to the shop to assess and as is tradition we couldn't reproduce, even after letting the car cool off a bit. They raised it up to look underneath and no visible issues either. I also was watching the the 4x4i screen and there is no correlation of the thud with the lockers engaging/disengaging.

Any idea what this can be? I read it could be the incorrect oil or wrong quantity used but this was done at a trusted Land Rover shop and they verified with the dealer that they used the correct spec. I know when changing transmission fluid the computer has to recalibrate overtime or you have reset it manually, but apparently that is not part of the procedure for diff change.

Appreciate any insight or help here!