Correct Prop Nut Install Procedure for 2002 Sundancer 380, 8.1 V-Drives

[Pseudomind]

I have been informed that the procedure in the manual has been changed, does anyone have the latest procedure, bulletin number, etc from Sea Ray for replacing the prop nuts?

Thanks

 

[Petep]

I don't know about "service bulletins" but i do know how I do it- It is BIG nut THEN LITTLE nut, then new cotter pin. Never "jam" a block of wood as it can throw off your newly scanned blades. Would love to hear more!

 

[Vince_nj1]

I don't know about "service bulletins" but i do know how I do it- It is BIG nut THEN LITTLE nut, then new cotter pin.

:thumbsup:

My props were installed with the little nut, then then big nut. I removed them last fall and sent them out to be scanned. I had a conversation with the owner of the prop shop and he told me that the correct way is the big nut, then the little nut.

 

[Petep]

It's been sort of an "ongoing" argument....I think I believe the logic from my sources that show big nut-little nut. I have heard both sides.

 

[Pseudomind]

It's been sort of an "ongoing" argument....I think I believe the logic from my sources that show big nut-little nut. I have heard both sides.

So have I and I am planning on having my props done, and want to insure they are put back correctly. :huh:

 

[Jimmy Buoy]

Michigan Propellers - Inboard Prop Install Procedures.

1. Push prop snugly onto shaft taper WITHOUT key in either keyway (prop or shaft)

2. Make sure prop is snug and there is no side to side movement by gently moving prop back and forth.

3. Make a line on the shaft with a non-graphite marker at the forward end of the prop where it stops up against the shaft taper.

4. Remove prop.

5. Put key into keyway on shaft taper with radiused or chamfered corners (down) in shaft keyway (if prop shaft keyway has radiused corners).

6. Put prop onto shaft taper.

7. Check to see that the prop moves back to the forward line made in Step 3. If it does, skip down to Step 8. If not, perform the following:

a. Remove prop from shaft
b. Place a file on a flat surface area or work bench.
c. Run opposite end of chamfered key back and forth over file (to remove any burrs) with a downward pressure on key until side being filed is clean.
d. Install cleaned key in shaft keyway with chamfered corner side down in shaft (the cleaned, filed side up in keyway).
e. Replace the prop on the shaft and fit snugly on taper. Check to see if it reaches the line as made in Step 7. If it does no, then repeat a-e.

8. When propeller hub moves to correct position, install prop nut on shaft and torque to seat the prop. Install the torque jam nut also, if your shaft is so equipped.

9. Install cotter pin at end of the shaft.

Note: The nuts must go in order but the method I have found effective is to draw the prop up with the large nut, then replace the large nut with the small nut and "jam" the smaller with the large nut. Also, never "block" the prop to immobilize the shaft (you'll bend a prop blade). Instead place a pipe wrench on the shaft and block it using a piece of wood between it and the hull.

I've used this method without any issues. :thumbsup:

 

[dpmulvey]

What Jimmy said. Skinny nut then fat nut. Has to do with stress on the threads and potential for stripping.

 

[randerson]

What Jimmy said. Skinny nut then fat nut. Has to do with stress on the threads and potential for stripping.

I just removed my props and will be installing re-scanned props this weekend. Both my owners manual and the Michigan Prop manual say the same thing, skinny nut then fat nut. That's how I am going to do it!

BTW, when I pulled my props off, they were backwards, apparently the marine mechanics don't know either!

 

[FireIsland1]

I don't know about "service bulletins" but i do know how I do it- It is BIG nut THEN LITTLE nut, then new cotter pin. Never "jam" a block of wood as it can throw off your newly scanned blades. Would love to hear more!

here is how I can best explain what's happening and why there are two different size nuts. After the prop is placed on the shaft and the key is in, the thin nut goes on and is tightened to hold on the prop. now the fat nut is put on and tightened down tight. when the fat nut is tightened it takes the load off the thin nut by compressing it against the prop. the load is now on the fat nut and not on the thin nut. you always want the load on the most threads. there is a reason that the nuts are not the same. If they were the same amount of threads they would share the load equally. that would allow them to come lose. if you did this in the opposite the thrust load would be on the thin nut and it could fail to hold and come lose. that's it, end of discussion.

 

[Southpaw II]

I can't speak to the mechanics of this, but I put mine on 3 years ago....big nut followed by small. Just made sense to me at the time. Then the cotter pin. They're still there. Next time maybe I'll do them each differently.

Don