Reassembly lower unit stuck at 1/2" to go Alpha 1 gen 1

[BCreech]

Changed my water pump impeller on my alpha one-Gen 1. I am trying to put the lower unit back on the upper. I have got it almost on but there is a 1/2" to go. (See pic) I feel like its getting stuck on something. I assume the driveshaft but I can't see anything. Could be the shifter. Does anyone have advice on how to get it to go that last little bit. Has to be a way to get it on there without taking off the upper. Thank you for any help!!

 

[Scott06]

Is it in gear hold the prop counter clockwise to keep it from popping out of gear and rotate prop shaft likely splines on drive shaft aren’t synced up with splines in upper

 

[BCreech]

I got it on there. Just had to rotate the prop a little bit. Thanks!

 

[Rick Stephens]

I would recommend you always take the entire drive off. It is too easy to damage seals lifting the lower up onto the upper. And it is SO easy with the lower slid into a slot made from plywood or 2 x 4s or whatever, to drop the lined up upper down and not hurt anything. Besides, annual maintenance includes inspecting and greasing u-joints, gimbal bearing and bellows, none of which can be done with the upper left on the boat. Taking the outdrive off is a under 15 minute job.