shaft alignment

Picking up on a thread I started a while ago...

Mark, I tend to agree with what you said before that my alignment issue was not because of the way the boat was blocked. Here's where I am and wanted to get some input. I'm supposed to go in sometime this weekend.

When I hauled the boat, the port side shaft was almost touching the bottom/right corner of the shaft log. It wasn't "actually" touching, there was no evidence or vibration/noise last year. The cutlass bearings are both tight with no play. Over the winter, I replaced the stuffing box and hose on each side and cleaned up and re-bedded the shaft logs. When I disconnected the side in question, I could see it was off by a lot. Once I got into it, I also noticed that the left front trunnion engine mount was only about an 2" from the end. The Crusader spec is 1" exposed and I'm at an 1.5"

The off center shaft log/shaft relationship has been bugging me. In order to get it more centered, I can do the following:

Loosen the clamps on the stuffing box hose and shift it to the left about about a 1/4". By doing this, the end of the hose doesn't sit exactly flush with face of the shaft log on one side now. There's still plenty of hose on the log no issue there. BTW, these are "self-aligning" spud style stuffing boxes.

I called Buck Algonquin and they said this was actually a good idea and would save time in "wearing" in the new stuffing box. I guess the SS shaft does wear into the bronze after some time to find its "spot". I can see that if I look at the old one. This part could actually be good news and once it goes in I can do my final alignment.

The downside is now there's a slight gap on one side of the cutlass bearing because I've shifted the shaft over. At some point, I assume it'll wear into the other side and eventually cause a vibration. It really wants to be more to the right because I'm sure it's been that way for years. It rotates fine, it's not binding up but is slightly tighter in this position than where it was. I guess that's to be expected.

The million dollar question is can I run it a season in this new position? I just don't know how quickly these cutlass bearings wear and how many hours in before I have a potential issue?

I know I can get the engine aligned doing it this way but probably need to replace the cutlass bearing and/or change the strut alignment. Again, no play now but a slight gap that wasn't there before. I could probably put it back the way it was but I just don't like the idea of the shaft being so close to the log, not much margin for error if it shifted out of alignment.

I'm trying to make this decision now while I can still see under the boat.

thanks,
Bob

BOb,

This is a well versed and pointed question and I WISH I had pearls of wisdom to offer . I did read that the cutlass bearings should be squarely aligned to facilitate lubrication and minimize wear. Ours were certainly loose and sloppy but there was no affect to the shaft regarding wear and having had the struts off to replace the backing plates, we aligned (hopefully) to the shaft log and coupler. Our shaft logs were so worn that had it not been for the MEDIOCRE hose attachment to the stuffing box, we clearly would have had a major problem any day. Truly the ticking time bomb.

I know this alignment thing is a BITC# because you apply some major labor in tight places (ours is a v-drive) and poorly aligned drive components cause vibration and wear. Of all of the systems on our boat that have been seriously overhauled....THAT one remains to be viewed (by me) and not really 100%....close but no cigar. Tough choice ahead and after all you have done....I wish you luck

I guess the SS shaft does wear into the bronze after some time to find its "spot". I can see that if I look at the old one.

Click to expand...

Bob - I've never seen a correctly done installation where there was any metal-metal contact on the driveline. The flax will "seat" on the shaft but none of the metal components of the stuffing box or the logs.

As long as you can rotate the shaft by hand, it should be sevicable. As long as there is no radial play in the cutlass bearing, it should be serviceable. If the rubber is in good condition and the shaft is clean, you should be able to make it thru the season.

You want to keep the concentric components on the same centerline - log and stuffing box in particular. When the stuffing box gets "tilted" too much, you'll find the flax will require much more attention. If Buck's staff endorsed your concept, there should be any major concern.

If you wanna go boating and can afford the potential "extra maintenance time", then lauch her. if you have no surplus time, I'd suggest getting it right, now, as it will minimize any "lost opportunities" to enjoy the time on the water. (Probably be cheaper in the long run, too.)

thanks guys... I have a guy (hopefully) coming by tonight to take a look. The cutlass bearing are in excellent shape and so is the shaft. I'll see what he says tonight and then make a game time decision about tomorrow.