stiff gear change td5 disco

hi guys, i'm have trouble putting into 3rd gear mainly going down the gears. ANY THOUGHTS???
I had a reconditioned gearbox put in as mine developed a chipped gear, it fixed the problem but a couple of weeks later there was a rattle on the forward facing gears, 1st,3rd and 5th. i took it back to the garage that fitted the box and it turned out to be the 2 springs on either side of the gear lever to centralize it. they said it was the springs had worn quite away into the gear stick and was rattling. so they fitted a new one which fixed the problem. but now when im going into 3rd either up the box or down i have to rattle the gear stick from left to right slightly for it to locate ... has anyone came across this problem before, the nylon ball was badly worn on the gear linkage he took off. I'm fairly sure its not the box, just the lever, does it need ligning up for directional travel?? ANY IDEAS GUYS. CHEERS

the springs are positioned by the bias plate behind the lever you can either slacken the four bolts and move it a little so the springs hold the lever exactly in line with 3rd 4th or tap the the top of the tab over a little to achieve the same, i usually just weld the grooves in the stick up and grind smooth