gear lever doesn't engage smoothly

[ugabulldog]

Clutch pedal is adjusted correctly according to owners manual, tractor has 280 hrs, I have had for about 50 hrs and it has been this way since I bought it...... When I shift main gear lever or shuttle lever, sometimes there is resistance. It will shift and doesn't grind but doesn't go into gear as smoothly as a car. Also, when I shift the dual range lever (high/low) from neutral to slow, (and main gear lever and shuttle shift lever are in neutral as they should be) sometimes it won't go and I have to shift main and shuttle levers into gear, then back to neutral to get dual slow lever to engage. Do these conditions sound normal or what could be the issue? The only other tractor I have had was an old 245 before this and it was the same way except you could hear the grinding in the gearbox.