Another driver turned in front of me the other day and my F2 SD4's OSF quarter got quite a bit of damage. List of intended repair from the insurers includes a new OSF alloy and tyre.

I've got all terrains on which came with 10mm tread and they are down to around 5.5mm tread now. Will 10mm on OSF and 5.5mm on NSF mess up the front diff or gearbox, or anything else, or is that OK? will it handle strangely / dangerously?

Anyone had experience of thissituation, and insisted on two new tyres to keep things balanced and safe?

Thanks for any info

You are caught between a rock and a hard place.
The repairs shouldn't make the car any worse than it was before the accident - on that even the insurers agree.
The car shouldn't be better than before the accident - that is the insurers take, fitting two new tyres means that you have a car in "better" condition than before the accident, as the originals were 50% worn.

Now you can accept that you will fork out to replace one part worn tyre early, but are getting two new ones for that price - overall not a winner, but not a loser. Or you can take the stance that all the repairs are down to his insurers, morally correct, but for £100 - £150 you are possibly going to be without a car for a week or two while the insurers mess you about, and trust me they WILL snatch back any hire car that you have while the discussions are taking place - been there, 40 miles each way in Taxis for two weeks last year.

Unlike the Freelander 1 fitting one mismatched tyre will not cause the diff, PTU and viscous coupling to instantly eat themselves. But two mismatched tyres on the rear axle may confuse the haldex system, I have done it on several occasions with the FL2 just to get me home, without any obvious damage.
Did it once on the FL1, drove from Wigan to Buxton, and by the time I got to work the car was trailing smoke from the rear diff, where it had boiled the oil and ejected it from the breather. Tangiers Orange - gone, missing her
Replaced by Ewok what a mistake - now a happy Disco Sport owner

Thanks.

I've asked LR customer services and they said they recommend even tyre tread across all corners. I'll see what the insurers say, its a no fault claim so not sure if that makes a difference.