45C cracked shaft

[elpescador47]

Hello,

I have a 1989 45c that I purchased a few years ago. I have noticed some slight performance issues with the port engine over the past few years: slightly higher fuel consumption than the starboard engine, more black exhaust on port than starboard, and then most recently I started having vibration issues on the port side. A mechanic checked both engines and the alignment and told me he thought that the port prop shaft was slightly bent.

So I pulled the boat last week. The yard rolled both shafts and said the port was bent, so they sent it out to Wilmington Iron Works (I'm in Los Angeles) who evaluated the shaft and discovered that it is not only bent, but it is cracked. They say that the shaft has "short keys" instead of the tried and true "long keys," and mentioned that they've been seeing this more frequently. They think this may be related to shaft failure. They've quoted me $4800 for a new prop shaft.
They've recommended that I send starboard shaft in to check for cracks. The starboard shaft is already back in the boat (after it was rolled at the yard and found to be straight). The yard is quoting me $1000 to remove the shaft, send it to Wilmington Iron Works, and put it back in. At this point I'm leaning towards not doing this as I have not had issues on starboard and it was rolled already (and found to be straight).
This is my first time dealing with something like this. Any advice from the forum?

Are these reasonable prices?

What about a used prop shaft?

What questions should I be asking?

Thank you!

[Pascal]

What size are your shafts? What material, AQ22HS or a lower grade? $1000 to pull a shaft that was just installed seems expensive since the coupler will obviously come off easily

If one is cracked, i would get the other one magnafluxed, maybe done in place

A few months ago, i had a 3 1/2" aq22hs shear while cruising in 22' water in the Bahamas (84' lazzara). Took two days to find the 40" veem... when we hauled out back in miami i had the other shaft pulled and magnafluxed, it was cracked too...

Cost for each 3.5" 126" AQ22HS shafts was $6300

[motoryacht lover]

I agree with Pascal $1000 to pull the shaft seems expensive. I have been through the cracked shaft thing and if I felt comfortable spending the money I would have the other shaft pulled and checked. There is a dye test that can reveal cracks maybe that is called magnafluxing. Apperantly these shafts fatigue over time and most of the problems occur at the taper and also ask if they radius the key way. It is a pretty big safety issue if the shaft breaks underway and is thrown up and into the bottom of the boat. Shop may have quoted you high ask if they would be willing to do it time and material.

[Cricket]

I don't think $1000 is excessive to remove and replace the shaft plus delivery and pick up from where it's got to go for inspection.
Remember we're talking California costs, not Florida.
If it was me I would replace both shafts now, especially since the key way is not proper.
Or, maybe they can re-machine the key way???
Btw, we check our shafts with dye/magnaflux every time we pull the props.

[Westfield 11]

I don't think $1000 is excessive to remove and replace the shaft plus delivery and pick up from where it's got to go for inspection.
Remember we're talking California costs, not Florida.
If it was me I would replace both shafts now, especially since the key way is not proper.
Or, maybe they can re-machine the key way???
Btw, we check our shafts with dye/magnaflux every time we pull the props.

Do you have them check the entire shaft or just the business end by the taper and the key way?

[elpescador47]

Thank you for all of your responses.

I went to the machine shop today. The crack is pretty impressive, especially with the magnaflux on it (I tried to attach a picture). The guys there think that is the key itself that is too short, not the keyway. They're going to make new keys (for both shafts) that are the appropriate length.

In light of all that, as well as your comments, I am going to send the starboard shaft in to the machine shop to be evaluated. The yard is going to charge me labor time, and thought it would about 5 hours given that everything was removed last week (and should be relatively easy to get out). So less than $1000.

I found a new "old stock" Hatteras 45c prop shaft online. A guy who has a marine surplus sort of store bought out of the inventory of a Hatteras dealer when they went out of business a few years ago, and that was part of the inventory. With shipping, it's going to cost me about $1350. The guy doesn't know much about the shaft, but it's in a wooden box that says Hatteras 45c (hand written in pen) on it, has an inspection tag on it that says Hatteras 45c, and the inspection tag dimensions (2" x 12' 9") correlate with my shafts' dimensions. It's a bit of a risk given that I can't check it out, but I think I'm going to do it. I'm going to have it shipped the machine shop so that they can inspect it before I have it installed. Shipping, by the way, is ~$500 because it's over 12' long and the seller lives in some rural area.

I'm assuming that a shaft sold by a Hatteras dealer should be high quality. Any thoughts on how reasonable it is to assume that?

At the same time, the machine shop has already ordered the stainless steel to fabricate a new shaft (AQ 22HS). They seem to have no problem if I don't have them fabricate a shaft for them--they'll just stick it on the shelf and sell it to somebody else. Hopefully not to me, although we'll see what the starboard shaft looks like.

45c cracked shaft.jpg

[Fanfare]

I think you need to know exactly what the shaft steel is. AQ22HS is the strongest there is, last time I checked.

I have 6V-92TA engines at 550 hp driving two inch shafts. The naval architect who supervised my installation 25 years ago said that AQ22hs was the only steel to use. There is a lot of stainless shafting out there. Given the cracking you already have I would not consider an unknown shaft with only a handwritten notation on the box. These engines came in two horsepower ratings, probably 550 hp and maybe 450 hp. What if you have the wrong one?

Maybe your shaft shop can test the hardness for you. But I don't think I would take the chance.

[Pascal]

I may be a little cheap sometimes but not when it comes to wheels whether on the road or in the water. On the road I look for the softest possible rubber to get max grip. In the water, trying to save a few bucks on shafts is a gamble too. Have a good prop shop donthe calculatuons to see which shaft material will work for your boat. Maybe standard AQ22 will be fine or even lower. Maybe Hatteras can confirm what material they used back then

By the time you pay for the labor, etc the extra $ for the best possible SS stock makes little difference

Raising a 40” wheel from 22’ without tanks after a two day search isn’t something I want to do again

[Cricket]

Do you have them check the entire shaft or just the business end by the taper and the key way?

We added shaft tubes so we can only see from the aft strut to the end.

Also, your keyway is not "spooned" at the end of the keyway, makes a big difference in protecting the keyway from cracking.

I'm with Pascal on the shaft in a box, not knowing what the material is. sometimes the boat builders don't always purchase the best materials, yes even Hatteras. Sort of like "dealer" or OEM tires for cars....
When the shafting material is made the foundry tests the batches for actual breaking strength numbers, the machine shop should be able to select from a list when they purchase. Can make a big difference for a borderline application.

[Toolsntoys]

I recently had to do the research on props and shafts for my repower. I can tell you that’s it’s important for you to know your materials and the safety factor for your shafts. ABYC recommends at least 5.0 safety factor. Do you know if the props have every been resized? If so that can dictate what material shafts need to be to not lower you safety factor