Your alignment tool is made up of three precisely sized shafts. The smallest fits exactly into your coupler. The next is sized small enough to pass through your bearing with room to spare, and is long enough to allow the first shaft to engage the coupler 1/2 inch before the larger shaft, sized to exactly fit the gimbal bearing contacts the bearing.
You should feel it bottom out when you slide the bar in. You want the alignment bar to slide in with very little effort and you want spiline marks to be equal all the way around the tip if the bar.
First thing you need to do is make sure your gimbal bearing is set.
Using your alignment bar insert it through the gimbal bearing and just so it starts to go into your coupler. (approx. 1/2 inch)
Using the palm of your hand, give the alignment bar a couple of "whacks" on the top,bottom and both sides of the bar. This will ensure that the gimbal bearing is at the correct angle to your coupler.
Coat the 1st 2 inches of your alignment bar evenly with grease.
Put a mark on your alignment bar near the handle so you can keep your bar in the same orientation when inputting and removing it from the coupler.
Slide the bar into the gimbal bearing and into the splines of the coupler and without twisting the bar pull it out.
You should see spline marks evenly around the end of the bar.
Are the even?
Turn the engine over 90 degrees and check again.
Keep turning engine over in 90 deg. increments. This ensures that your coupler is centered and true. Ater the engine has turned 360 degrees go ahead and tighten and torque down the front motor mount top nuts. Check alignment once more just to ensure that the engine has not moved while tightening.
Are the spline marks heavy on the top or the bottom?
If they are heavy on the top you need to Lower the front motor mounts half a turn and check again. Keep doing this step until you achieve the results listed above.
Put marks on the motor mount nuts to make sure you turn them both in the same increments.
If the heavy spline marks are on the bottom you need to Raise your front motor mounts half a turn and check again. Keep doing this step until you achieve the results listed above.
Here are some videos to help you along.
This one is showing you when its not aligned. Notice how he uses his hand to smack it in.