Prop Shaft Alignment Yearly Maintenance Item

[gregski]

I performed this alignment this weekend. It didn't go as smoothly for me as it should have. The whole concept/procedure here is quite easy but if things aren't moving freely, it can be a real PITA.

1. I think that you can simply loosen the coupler bolts to check for alignment but if you need to adjust (or by more than "just a little"), I would suggest removing them at that point. One problem I had was that by not removing them, the bolts and the "lip" of the flange would interfer with proper measurements/alignment. I chased my tail for a while here.

2. I needed to adjust the "yaw axis" but the engine mounts would not slide freely on the trunnion pins. Age and corrosion were certainly part of the problem here but I suspect that the trunnion pins are somewhat "locked" in a parallel horizontal axis. After a few bashed appendages, I needed to change course. I was also going to need to make a vertical/pitch axis adjustment so I released the locking nuts and made some adjustment there. Then, things finally started coming together and I was able to move things more freely horizontally on the trunnion pins. So my take away here is that you need to release the locking nuts to allow the trunnion pins to turn a little about their "yaw axis".

I hope that from here on out, I'll mostly just need some minor vertical adjustments, in which case this will be a piece of cake!

[trayson]

After breaking a shaft, I had to of course do an alignment. (because being out of alignment was undoubtedly the cause of breaking the shaft in the first place).

it's certainly like an upside down geometry puzzle on a v-drive. It was way easier on my direct drive! My front pins were so seized that I literally bent my prybar. But I was able to get all the necessary adjustments on the rear. I was starting to get disheartened thinking I'd never get anywhere close to that magic 0.003" but I started to get close after a while and once I got within spec, I STOPPED messing with it and locked everything down.

[hans]

Hi I want to check the shaft alignment on my boat. I found this video on youtube: https://www.youtube.com/watch?v=5UqniaiggKA.

In this video the guy says that the clearance between the shaft and the shaft log ( where the shaft goes though the hull) must be checked.
So do I have to remove the dripless shaft packing to be sure that the shaft is in the center of the shaft log or just by removing the coupling bolts the shaft will be in its natural position and automatically there will be a clearance between the shaft and the shaft log?