How do you get the drive to slide back in? How do you keep the shaft from dropping once the universal slides through the hole?

Go to the long Island Boaters Club web site, http://www.liboatersclub.com. The have a vidio that shows how to pull the B3 off and put it back on.

I'm thinking he means speedmaster 3 with no gimble bearing. I've seen string or tape attached to th input shaft and held up from the inside

I've used zip ties on the u-joints to hold the shaft so it sticks out straight, then slid it in the spline and pulled the drive back just enough to cut the ties and remove them. Still took an hour!

My trick is to get the cardan joint in just the right position so you only have one hinge trying to flop instead of two, and help hold the shaft up with a long thin screwdriver as you insert it in. I usually use a shop crane, and park it so it wants to swing in on its own. That gives you one less thing to do. Once inserted, you have to usually turn the propshaft a little to get the splines to engage. Sometimes it takes a half hour, but I've gotten lucky and stabbed them on the first try too.

Don't forget to grease the splines. Nothing worse than getting it fit up and having to take it right back off.

I know this sounds bad but I used duct tape on the u joints works fine and now has 102 uses...

Yep, but we used masking tape. Just have to get all the grease off the joints so it will stick.

Tried that, but in my application I couldn't get the shaft straight enough.

http://www.mercruiserparts.com/Show_...PAGE+1+0F+2%29

There is supposed to be a spring on the end of the female coupler that helps guide it in. Is that there? It also helps to hold the inner bearing race on, so best to not remove it.