A friend taught me this method and I have used it several times now. It works like a charm. Turns an agonizing procedure into a 5 minute job. Make sure the bush on the drive gear is easy to rotate and put some "three in one" light oil on it. Install the gear with the "master spline" located at the two o`clock position when standing at the side of the engine. Advance the gear as you drop it in as it is aligning on a skew gear. Check that it is at the correct position. Using a pair of long needle nose pliers, grip the inside of the drive gear and with a bit of a twisting motion, move the gear up and down without disconnecting the gear. At the same time put a thin screw driver or a piece of wire inside the screw hole so that is just touches the drive gear bush. As you move the gear up and down the bush will rotate and you will soon feel the hole "arrive". Do not let the bush bottom out or the hole will not align, keep it just slightly of the bottom position and install the grub screw with a bit of loctite. Do not over tighten or you will bind the bush.Remember, there is a small oil hole opposite the grub screw hole on the bush. Not the hole you are looking for.
Brett
Series 3 88 Diesel Soft Top
Ex-Mod 110 Tdi