E35-2 Prop Shaft Replacement

[bradh]

I am Atomic 4 powered. At end of season haul out, the prop shaft looks bent. 3/4" diameter shaft, but it looks like a 1" opening in the through haul. I plan to change out the stuffing box, new Cutlass bearing, and larger diameter shaft. Anyone done this fix and have thoughts or things to watch out for?

Thanks,

Brad

 

[Afrakes]

Why upsize the shaft?

Don't see any reason to go larger with the shaft. If it truly is bent then there is a specific reason for that. Does the shaft extend too far aft of the bearing causing the shaft to "whip". Is the prop the correct size? Find the root cause of the bend and then just get a new 3/4" shaft, cutlass bearing and stuffing box, if the existing one can't be cleaned up and reused.

 

[dt222]

Wouldn't a larger shaft mean a larger/different strut?

Don

 

[bradh]

Rationale

Al,

I am basing the change off 2 items: our yard mechanic when he looked at it said it looks rather small to what he would expect for the boat and also when I was researching the boat a couple reviews (http://www.boatus.com/boatreviews/sail/Ericson35.asp) mentioned it as being undersized: Though I would expect those are relative to a shear failure (not a bend).

As far as root cause - I am unsure. At no point in this season do I remember ever feeling like we struck anything and there is no other sign of a strike.

Brad

 

[bradh]

Whip and Strut

Good point on whip. I will get some dimensions and check them.

As far as the strut, Yes I may need to do that to fit in an larger cutlass bearing. It looks close.

Our yard had good locations for straps and they are very good. I was at the haul out, so I am almost certain they did not get a strap across the prop (the bend is not overly severe either).

So I am getting the feeling this is not a "standard" change.

Brad

 

[Emerald]

I'd do some more checking before going to a larger size shaft, but thinking about the bend. I would expect a lot of vibration if you had been running with a severe bend, which brings back the question of a sling or something snagging it at haul out.

 

[bradh]

Sorry - to be clear, it's not severely bent. You can just pick up the bend by looking at run-out between the shaft and hull through hole (simarly at the stuffing box).

Brad

 

[Christian Williams]

But there is vibration?

 

[Afrakes]

Shaft

Assuming that the shaft might be as old as the boat maybe: Some time in the past a PO let the cutlass bearing wear to the point that "whip" did develop. Simply replacing the c-b might have masked the problem enough to ignore. My former A-4 powered 73' E-27 had some vibration when I got her. I pulled the shaft and found that it did have a slight deflection as well as significant wear at the bearing and stuffing box location. In addition, the coupling was well out of alignment. I had a local machine shop fabricate a new shaft. After replacing the shaft, cutlass bearing and realignment I still had vibration but it was much less.

 

[bradh]

Plan

The amount of vibration was not really above any level of significance.

Hmmm - so it sounds like a tear down and inspection before any decisions. That's the direction I will head.

Thanks all for your input.

Brad

 

[Rocinante33]

AFAIK all Atomic 4 powered boats have 3/4" shafts. I'm not certain about it, though. You might ask about it on Moyer's web site or news group.

 

[Afrakes]

1" shaft

Some boat manufacturers did use a 1" shaft with the A-4s. I purchased an A-4 out of a Tartan 30 that was fitted with a 1" shaft. I still have the coupler sitting on the shelf if anybody needs one.

 

[Sethro310]

E35-2. Prop shaft question

Was diving on boat to clean bottom and noticed thread on prop shaft is corroded away badly. Live few miles away from Minnie's and am looking at the inventory of 3/4 prop shafts . Any chance anyone would know approx. length of shaft? Boat is a E 35 - 2. 1971 hull# 179. A 4 power . Any info. Is appreciated.

 

[bradh]

Reprop.

I'll try and answer a question and then ask a bunch of new ones. I just pulled mine (72' 35-2 Atomic 4 under the dinette). 46 1/8th in.

Now for the question.....

I pulled my shaft because at haul out, I could see what looked to be run out between the shaft and the hull (where it enters at the water). When I removed it, I noticed about 5-10 degrees of slop/backlash at the coupling (Is that normal or excessive?). The key way on the coupling looks to be distorted. Also the detent location on the shaft for the coupler set screw looks a little beat up (see picture). When I put the shaft on a granite surface plate, I only get about a 0.010 in of bend (is that excessive?). I am wondering if the shaft is not really bent all that bad and the run out I observed was just due to slop in the key way caused by misalignment?

So I am trying to decide how carried away to get here....
1) new coupling, cutlass
2) new shaft, coupling, cutlass
3) new bigger 7/8 shaft, coupling, stuffing box, cutlass, reprop with an Indigo

I currently have a 3/4" shaft, with a Michigan Saiiler 2 blade 12-7. Option 3 comes down to how great is an Indigo on a 35-II and how much does it add drag under sail?

Brad

 

[toddster]

Been shafted before...

I fell into a cascading trap of repairs on the driveline before, as discussed here. It seems that if you try to replace or upgrade one item, you end up replacing everything. $$$$$

The length of the shaft seems to depend on issues such as the hull clearance for whichever prop you select. The kibitzers on the thread linked above were aghast at the amount of shaft behind the strut, but I've seen similar amounts on other Ericsons.

I did go with another 3/4" shaft, but it wasn't easy to get. Every place on the West Coast told me "they don't make them like that any more" but I got one without much issue from an East Coast place.

Oh, that shaft end looks OK to me, but most of my experience is with farm equipment. Sometimes they get a little banged up because somebody in the past used a key piece that was too small - sometimes the correct one doesn't look like it will really fit.k.

 

[bradh]

Toddster

Great post title. I actually did not have much "overhang". Only about an inch between the strut and the prop. Great read on your drive line fun. Thanks for reminding me about Moyer's Forum. I went ahead and posted this there also.

Brad

 

[Afrakes]

7/8" shaft, No way

If you go to a 7/8" shaft your problems and cost will really be compounded. You'll need a new strut, stuffing box, coupling and probably a new shaft log. Stick with 3/4", replace the shaft, cutlass bearing, stuffing box packing and go for a split coupling. The prop should not overhang the strut by more than an inch.

 

[bradh]

I don't think I will need a new strut. The current strut has a 1 1/4" ID and there are 1 1/4" OD x 7/8" ID Cutlass Bearings available. The shaft log is 1 1/4" ID through also. I would need a new stuffing box. Let me know though if I have missed something.

Thanks,

Brad