Bravo 3 propshafts and propellers!

[William Miller]

As part of a larger project, I pulled the drives last year.
I replaced the propshaft seals and I'm glad I did.
I found one of the outer shafts (tube) was scored at the seal. Possibly from the seal that was rusted.

I also had a ding and chip in that propeller. I filed it out and ran it.
All good but found my stbd drive lube needed refilling. After a hour or two run, I would come off plane and the low oil alarm would buzz. Late in the season so I kept a bottle on board to take care of this as it came up.

Pulled the boat in November for the winter. No sign of a bad leak. I assumed the oil was cold and thick.
Went back down to the boat on a warm day last month to pull the props and take a look.
Its leaking at one of the seals. Just a hint.

Pulled the carrier and can see the scored area in the big shaft.
Ordered new shafts, seals and carrier needle bearings.
Pulled the lower drive off yesterday brought it home hoping the parts show up Monday.

So I start thinking as I lie in bed. What caused this?
My other drive is fine.

So here are my three thoughts:
Did the old seal rust and swell up and score the shaft?

Did the shaft bend when the prop got the ding?

Is the prop out of balance enough to force the shaft into the seal? I guess filing it down could have done this. There is no perceptible vibration.

What do you guys think?

I'll get some pictures a little later

 

[William Miller]

The ding was about 1/4 of the size of a dime. Smaller now because straightened and filed the edge.

 

[scoflaw]

Stainless shafts score over time, normal. That little prop ding won't do it. That's why they make sleeves

 

[William Miller]

Stainless shafts score over time, normal. That little prop ding won't do it. That's why they make sleeves

Sleeves?

 

[scoflaw]

Speedy sleeves. They're paper thin and get pressed on the damaged area where the seal rides.

 

[William Miller]

Where to get?
I have a set of new shaft coming but I'd like to see that.

My daughter will be working at the National Seashore this summer.
I hope to come up a few times this summer.
Will need some local knowledge!

 

[scoflaw]

Google it "speedi sleeve" Mc Master Carr is one source

 

[William Miller]

Google it "speedi sleeve" Mc Master Carr is one source

Thanks!
Learned something today!

 

[William Miller]

New shafts delivered today.
The large one came with the bearing and seal installed. Also the thrust bearing.

Took measurments of the seal area for reference.
1.5" for the small shaft
2.5" for the large one
I saw they do make the speedi sleaves for these sizes. Ill look up the part numbers.

Cleaned up the props yesterday.
I should have cleaned out the water intake and exhaust sections of the housing BEFORE i pulled out the carrier.
I did that on the boat because it held it solid while unscrewing the carrier.

REVERSE THREADS

 

[William Miller]

 

[Scott06]

Not that this helps you now but if you ever get into it again these guys repair the shafts and chrome the wear surface which is harder than the original shaft at the seal surface

http://www.jrmarine.com/products/bravo3_prop_shaft_seal.htm

also highlights that what you experienced is not uncommon.they also buy core shafts if you want to recoup a few bucks with your old shafts

 

[William Miller]

Some pictures from yesterday's project.
This is my simple outdrive stand. Has lasted a few seasons.
Great in both vert and horz orientations.

Made a bracket for my dial indicator. It was stiffer than it looks.

 

[William Miller]

Not that this helps you now but if you ever get into it again these guys repair the shafts and chrome the wear surface which is harder than the original shaft at the seal surface

http://www.jrmarine.com/products/bravo3_prop_shaft_seal.htm

also highlights that what you experienced is not uncommon.they also buy core shafts if you want to recoup a few bucks with your old shafts

I saw this and it looks like a good alternative.
Was it about $350?
The second is the sleeve which is about $60
First I guess is a new shaft. $1250 or more.

Scoflaw suggested the sleeves which I might test with my now "spare" outer shaft.

 

[William Miller]

checking to see if outer shaft is bent. I rotated several times and the needle stayed between the two pointers.

 

[William Miller]

Inner Shaft:

I forgot how to read this meaning , what range is the indicator measuring? How many zeros after the decimal point?

Also, my setup is not measuring the difference between the two shafts.
If the outer shaft is bent, the inner one will show it as they both are turning at the same time.

At least, whatever is not straight It is minute. Can someone read it for me?

 

[William Miller]

Bad news, Good news.....
The set I bought on ebay was not correct.
Correct outter shaft with the "THICK" thrust needle bearing.
It also had the inner bearing and seal already installed.

Bad news is that I think what is supposed to be the inner shaft looks like its a Bravo 1 or 2 single prop shaft.

Fortunately my inner shaft cleaned up like new with a few whipes with 1000 grit paper

 

[William Miller]

Installed the lower unit yesterday...All good so far!
Two quick questions:
1. Should the pitot tube "adapter" connector have an o-ring in the part that sticks down into the lower leg? I found the adapter fitting in the parts diagram. There is no separate part listed and I cannot see an o-ring on the picture because of poor quality.

2. Does the vertical drive shaft live in gear lube? When I first split the leg, the "spacer" stayed with the top part which seemed strange. There is an 0-ring at that joint, but there is nothing to seal the shaft. So my guess is that the drive shaft IS surrounded by gear oil. But then why is the little hole and seal needed? Anyone seen a diagram of this?