Evening all, when leaving Silverstone after ford fair last Sunday on my long drive home to the isle of wight the gear box started to make a very strange noise, instantly thought box had given up to select 4th and all very quiet. Gearbox is a CTS re con box done 8,000 miles in a 170 brake series one. There is still drive in 5th but it makes a nasty grinding noise when in that gear. So got it on a ramp today and pulled the end casing off and all looks fine nothing fallen off all where it should be, not pulled 5th of yet, any ideas what it can be that's failed.? The box drives as new in all the other gears with no issue, can select 5th easy as well. What do I try next? Pull the box apart. On idle it also makes a rattle noise from the far side of the box. The rattle goes when I put the clutch down. Thanks in advance guys