Another (and hopefully final) update: After two fluid flushes and the dealer's outreach to LR's Tech Assistance and corporate for approval, the rear differential has been replaced. It took a few weeks to get the part from the UK and then a few days to install them.

Thus far, the sound is gone, as is the sound/vibration that became increasingly more apparent at low speeds (towards the end you could feel the vibration if sitting in the back seat). I've driven it for several days and a couple hundred miles: so far, so good, unlike right after the times when they did the fluid flush and the sound came back the next day.

My car has ~37,000 miles and ~4 months remaining on the warranty. The major part used was LR135862, which appears to have cost between $4,000 and $5,000 alone. I have no idea how many hours went into the repair, but I'm confident it was substantial.

I appreciate everyone who previously posted about this issue and the TTB and provided some guidance. I love this car, and knowing a relatively well-known issue across many LR models has been addressed is reassuring.

 

Glad you got it fixed under warranty as it should have. Hope you never encounter this issue again.

 

Wait. Did these boneheads double flush the TRANSFER CASE and not the rear differential?

LR019727 is indeed the locking rear diff fluid
IYK500010 is indeed the transfer case fluid

I guess the question is, why would they have double flushed the transfer case. Something is fishy here because there are also no part #'s for the drain and fill plugs on the rear diff, which per the TSB must be replaced. They should be on the invoice. Either way you're sorted but... seems like this was not the correct action anyways a few months back by the dealer based on this document?

 

2022 HSE. Thanks to all the invaluable contributors on this thread.

Yep. I got the 'thumping' now. Started a few months back with an occasional slight lurch when I drove away from a halt. Now it's a thump, mainly on hard turns. Even had it on a straight line.

I'm now driving with the diff info screen on and I can see that it happens when the diff lock turns off (ie the diff icon goes to a lock symbol). It's livable, but never having one before, I don't know how bad it can get.
So I've printed out the service letter (SSM7589) and will show it to my dealership next month when I get my 3rd year service. Will post how it goes.

 

Count me in. Thumping and judder on incline coming from rear. Going to dealer for this and a loose steering/knock in bumps in about 10 days. I hope they can reproduce it.

Francisco

 

They could not reproduce both thump in back and loose steering. I drove with tech and did not hear thump (but again noticed it today). My second visit with the same complaints. Very frustrating. I will wait until my service is due in about 4 months. Luckily I have warranty until 2026.

 

I noticed a thumping after my diff was serviced on my 2020. I don’t think it was there before. It’s been consistent ever since, usually happens once when I first turn/really press on the gas after being parked for a while. I took it to the dealer a while ago and they recorded the problem and it coming as a result of having the oil flushed, but couldn’t replicate. I’m not worried about it, so long as it doesn’t blow up. Not something worth losing your head over IMO. Most rear diffs will have some quirk to them…

 

Thank you for your balanced perspective. Mine does exactly that. Soft thump on LEFT turn incline, normally after cold start then nothing for miles. I have a job that requires a bit of obsessive behavior and I am happy to listen to your input.

Francisco

 

Yep, every car I’ve owned with a diff has made some type of noise. There’s no way around it. The service guys, who I believe are actually competent at my dealership, weren’t concerned.

 

I have this, too. I had my rear diff flushed, and my friend who did it also put in some Ford Motorcraft differential friction additive. It fixed the problem for about a month, but now I can occasionally feel/hear my rear diff clunk, but not as often as it was before the flush. I spoke with a friend of mine who has experience with tis problem, and he said that other than the clunking sound, there isn't anything to worry about, and he hasn't seen any differential failures caused by this on any D7 platform vehicle. I also spoke with another friend who is an engineer for JLR in the UK and he said not to worry about it. I'm going in to have the harness overlay for the keyless entry replaced next week, so I'll have the dealer flush the rear diff again, but after talking to several people with experience with the rear diff, I'm not that concerned about it anymore.