Still grinding gears :(

Hi all, I posted on here a while back about the gears engaging but grinding on my P38. when I slip the gears in to low N, then let the lights and beeping stop then select drive. It moves and sounds like it's in low but a lot more grinding. Stop and then move gear selector to high N, let lights and beeping stop and select drive and again it moves but still sounds like it's in low with excessive grinding. It worked perfectly fine before I got recovered to a garage In west wales.
I got recovered because the RR went into neutral on its and when I got under her there was no oil in the gearbox. They filled in back up and when I drove off it was in Low and wouldn't move out. Since this I have replaced the motor on the back in the transfer box (with box set to high, motor set to high and ecu set to high).
Sorry this was long winded but I'm really struggling to get my beauty back up and running fully a smooth like she does

HELP!!!

Was it towed for recovery? If so was fuse 11 put in? If not and it's auto, box may be fecked. Have you checked for oil in the transfer box?

sounds like t/box isnt selecting or is broken ie epicyclic gear set

No oil in the gearbox ? that may be a clue !!

Not towed for recovery no it was up on a lorry.