Install new packing before shafts go back in or after?

[Unchained]

Hi everyone, I'm in the process of installing the driveshafts back in my boat, after replacing the cutlass bearings (as well as many other things) and was thinking it might be easier to install the GTU packing material ahead of time. Both engines are out of the boat and I have new couplers already fitted to the shafts, so I was going to slide them back in from inside the boat. Is this not a good idea? The shafts are clean and smooth and I was going to lightly thread on the packing nut, maybe two threads. Also, what should I lube the cutlass bearing with when sliding it in...soap, vaseline? Any tips or suggestions would be great.
Thanks,
Mike

[prowlersfish]

I would install the packing after you install the shafts . Its the only way to size it to fit . soapy water to lub the cutlass .

[Big D]

+1
If you install fresh packing first then slide in the shaft, you may end up cutting, pushing, or distorting the packing. Ensure that the packing is in and the nut is snugged up in place (not too tight) before you check alignment. Final tightening of the nut should be done after launch so you can tighten only enough to stop a steady stream. A slow drip is normal. There are a lot of posts here on the subject of what is an acceptable drip.

[Unchained]

Thanks guys, it does make sense to pack afterwards. I did read posts on adjustment, so I should be good there.
Mike