Hi I have a my2010 auto fl2.

Yesterday when I started to move in reverse, there was a loud clunk and jolt from the rear diff, then when pulling away forward there was a louder jolt/clunk. Any movement even without throttle now results in further jolts/clunks.

Can is at useless dealer and waiting to be moved to an independent specialist appointed by the dealer. They want to drive it there because they dont have a recovery truck, but I am really concerned that it will cause more damage.

There was no noisy bearings or anything before the failure, so has anyone any idea what may have failed?

there was a loud clunk and jolt from the rear diff

It seems you have already diagnosed the problem area ? If car is under some sort of warranty just let them get on with it. If not I personally can't follow the logic of your posting. FL2 MY10 TD4 GS traded in at 2 years
FL2 MY13 TD4 GS Current

I have diagnosed the problem area, which is fine, but I am trying to preempt the potential cause, options and costs.

My warranty appears to have a £500 per claim limit so I am a bit concerned!

Any help appreciated.

Lost cause then as £500 is a good towing bill and never going to cover the repair of major components on one of these. My EGR valve done on the cheap was £500. If the diff needs replacing search on here what others have paid out to ensure no one loads your claim. You could ask Bell Engineering what a exchange diff currently costs and also ask cost of fitting. Once armed with that info you have a yardstick if it needs diff work to hold the price in the right area.

Maybe its just a broken track control arm at a few quid.  FL2 MY10 TD4 GS traded in at 2 years
FL2 MY13 TD4 GS Current

Have you checked that it's not a problem with the parking brake shoes coming loose or something like that? Mine used to go clunk sometimes when I had not driven the car for a few days and they would stick when I reversed and then let go. If a spring or one of the locating pins has broken you could get this sort of symptom. 3 x FL1 2 manual + 1 auto
5 x FL2 4 manual + 1 auto
Now Discovery Sport P250 MHEV SE

Good point dorsetfreelander, I tend not to think about that due to having the EPB system.

Going back to the £500 warranty looking at that list of repairs on your strap line you would need £5,000 to keep going.  FL2 MY10 TD4 GS traded in at 2 years
FL2 MY13 TD4 GS Current

"you would need £5,000 to keep going"

Probably an understimate, only one of my FL2s had no warranty and that cost over £1k . The rest were on LR extended warranty and I wouldn't want to own an FL2 without one. Running older and more complex cars like the FL2 will become increasingly problematic I suspect. Remember that when you buy an old car you are buying someone else's problems. 3 x FL1 2 manual + 1 auto
5 x FL2 4 manual + 1 auto
Now Discovery Sport P250 MHEV SE

Not quite true as all our cars over the last 15 years traded out have all been in A1 condition and only let go when I could get a new already built car well below book. The current FL2 is still here as its better than what is on offer new from LR or it seems any other make and the longer we keep it with decreasing trade up value LR will eventually loose our custom (or until I kill the mother in law ). FL2 MY10 TD4 GS traded in at 2 years
FL2 MY13 TD4 GS Current

The point I was trying to make is that I doubt if modern cars will last as long as the older ones, not so much because of rust or mechanical wear but rather that it will become harder to find someone with the right diagnostic equipment to pinpoint faults. Add to that the difficulty of obtaining spares so that they can pass the emissions tests and so on. I saw someone yesterday looking for a Mazda MX5 on Autotrader with a budget of less than £3k and there were lots of 02 reg cars available and I wondered how a 15 year old FL2 would fare eventually? I guess that the Mazda would be a lot simpler to maintain and emissions tests would be less arduous. 3 x FL1 2 manual + 1 auto
5 x FL2 4 manual + 1 auto
Now Discovery Sport P250 MHEV SE

I have also had the brake clunk noise but in my case it soon went away once the wheels had freed.