Hi all I'm new on here, me and my wife have just brought a FL Td4 with 75k on it, it's got full service history and had most of that by landrover, tonight she noticed that when changing from 4th to 5th there is a whining sound, oly for about 10 second after selection, then disappears, no pressure on lever and clutch seems good, it appears to be coming through the head lever, I only picked it up on sat, it's still under the standard 3 month warranty I'm just scared that it's something major, anyone else had the same problem or know what it can be, please help