there is a problem with my car and i dont know whether its the gearbox or clutch, basically if i change into first it sometimes wont let me and there is a loud thud heard then through the other gears the changes arent smooth it feels as tho 'pushing through a gate', earlier on i had to force it into first and then second because it was really stiff, the reason why i dont know whether its box or clutch is because the bite appears higher than before and if changing into second its almost non existant. please help