90 hp Mercury, gear shift rod coupling on long shaft engine

Recently changed the water pump on my 90 hp Mercury, 2008. On re-installation, I cannot seem to get the
gear shift rod coupler to make up tight. I took it the launch not knowing and the motor just spun in forward and
reverse. Took it back home and that is when I realized that the problem was the long shaft gear rod coupler.

How exactly is this coupler made up once it is taken apart.

thanks

You'll need to drop the gear unit again.Put the control in fwd,rotate the shift-shaft in the lower unit until you find the gears,three clicks close to one another.The middle is neutral,one clockwise is forward,put it in forward.Both control and unit must be in the same gear.To check,turn prop,it should lock in one direction and ratchet in the other.If it locks both ways,you are in reverse.If it spins,you are in neutral.

thank you haventaclue. I was a bit loss on what was what when on the gear rod coming from the lower unit, but I did put it in gear and it does lock in one direction and ratchet in the other. When you turn the prop it also turn the long rod from the water pump going into the cowling. I will report back the next time I drop the LU.. Also, what about the coupler that is supposed to connect the gear rod from the lower rod to the upper rod? I don't seem to be connecting it correctly as it still remains loose with play when the lower unit is all the way tightened up. This was the first time I attempted to fix my water pump and I was satisfied when I restored good water pressure, but now I'm second guessing myself on this other issue with the shift rod and coupler.

The coupling should match the splines on the shaft in the lower unit.If it is loose/rattling about,it is either damaged or is missing the bottom shaft altogether.
I should have asked if this is 2 or 4 stroke/cycle and if you post the number or have a look at the engine diagrams tab at the top of the page,find your engine and see if you have lost something