I Have a 1986 2.5 na diesel that i have had a problem with the vacuum pump drive snapping off in the scew gear, i have bought a new vac pump drive and scew gear i have take the pump off and the oil filter housing removed the 4mm grub screw and drawn the scew gear out all went well not i have put the new scew gear back in but cant for the life of me work out how to line the hole up in the scew gear to get me back on the road does anyone have any tips or can anyone help?