Masthead Sheave Replacement tips / suggestions?


Allen W.
 

I’m getting ready to replace my original masthead sheaves with the Garhauer Ball-Bearing Sheaves.
But Garhauer doesn’t sell a complete ‘kit’.
 
Catalina Direct has a Masthead Rebuild Kit that includes two 1/2” x 2” Axle Pins and 5 Bushings (7/8” OD and 1/2“ ID).
I’m wondering if the bushings are just ’spacers’ that are used to center the sheaves.
 
The stainless steel Axle Pins are likely fine, but I’d like to take bushings up with me as well.
 
Does anyone remember if they re-used their bushings or if that’s something that should be replaced as well?
 
Any tips or photos greatly appreciated!
 
 
I’m loving Tom Soko’s mast step idea, I’m probably going to do that as well!
 


- ALLEN

C400, 1999 Mk1, #154 San Diego, Ca


Boris Keselman
 

I replaced all four sheaves directly with Garhauer ball bearing sheaves no bushing required at all.  Used existing pins.

Boris,
C400MKII #234 ARGO




-----Original Message-----
From: Allen W. <wrenchaw@...>
To: C400@Catalina400-445.groups.io
Sent: Thu, Mar 24, 2022 2:23 pm
Subject: [C400] Masthead Sheave Replacement tips / suggestions?

I’m getting ready to replace my original masthead sheaves with the Garhauer Ball-Bearing Sheaves.
But Garhauer doesn’t sell a complete ‘kit’.
 
Catalina Direct has a Masthead Rebuild Kit that includes two 1/2” x 2” Axle Pins and 5 Bushings (7/8” OD and 1/2“ ID).
I’m wondering if the bushings are just ’spacers’ that are used to center the sheaves.
 
The stainless steel Axle Pins are likely fine, but I’d like to take bushings up with me as well.
 
Does anyone remember if they re-used their bushings or if that’s something that should be replaced as well?
 
Any tips or photos greatly appreciated!
 
 
I’m loving Tom Soko’s mast step idea, I’m probably going to do that as well!
 


- ALLEN

C400, 1999 Mk1, #154 San Diego, Ca


4speedfunk
 

Any advice on accessing the masthead?  Looks like there is a removable plate on top of the casting.  I would love to see some pics of what’s inside.

I am replacing my standing rigging and my manual states that the upper shrouds have eye fittings.  I assume they are somehow captured by a 5/8” pin inside the casting but I have yet to crack it open.

Boat is a 1997 MkI (#096) with a conventional z-spar rig.


Allen W.
 

I think this is where I was lost…
I think the Cat Direct ‘parts kit’ is a generic sheave with bushings for different axle sizes.
 
The 400 has a 1/2” axle and the Garhauer sheaves have a 1/2" internal ID, therefore, no ‘bushings’ needed.
 
Because I haven’t been up there, I thought the ‘bushings’ were some kind of spacer to keep the sheaves from moving side-to-side.


I'm going to try to get good photos of the process for future reference


keithsugg@sbcglobal.net
 

I have hull #100. I replaced the plastic masthead sheaves with Garhauer ball bearing sheaves before launching. I cannot recall all of the details, but my experience was that until it was apart and measured I did not know the dimensions - despite what Catalina or Garhauer said.

IIRC (and my memory is iffy at best - especially back to 2009) my first set were too narrow for the halyards. So I had to re-order sheaves in mid-commissioning. Then hubs of the second set were just slightly too thick to fit into the opening. Due to time constraints I chose to machine them down to a narrower thickness rather than re-re-order

The first photo shows the dark gray masthead casting atop the mast. It lifts off after removing the two through bolts secured with the black nuts on the sides.
The second photo shows the casting pulled "up" just enough to clear the mast cutouts and gain access to the axles and sheaves, with one of the too-narrow ball bearing sheaves sitting in place. With adequate time I'm sure Garhauer could have manufactured and delivered sheaves that would have fit w/o mods.
Third photo - another view.
Sorry I cannot help with the shrouds.

Carefully measure axle diameter, sheave thickness and the thickness of the space in the housing before ordering. Then measure what you receive.

I hope this helps, and Good Luck.

Keith Sugg
s/v Rendezvous #100

On Friday, March 25, 2022, 12:49:25 AM CDT, 4speedfunk <wilsonmech@...> wrote:


Any advice on accessing the masthead?  Looks like there is a removable plate on top of the casting.  I would love to see some pics of what’s inside.

I am replacing my standing rigging and my manual states that the upper shrouds have eye fittings.  I assume they are somehow captured by a 5/8” pin inside the casting but I have yet to crack it open.

Boat is a 1997 MkI (#096) with a conventional z-spar rig.


4speedfunk
 

Ahhh.  Pic is worth a thousand words!  Thanks Keith!

So it looks like I can change all the standing rigging without removing the masthead casting.  I can see in photo #1 that the two upper shrouds enter the mast via the windows and exit out the top of the masthead casting.  It appears there is a cross-bolt (or pin) that captures them above the surface of the top plate.  I assume I can swap those out without taking the masthead off?  Thats great news, as I was not looking forward to doing this 65-feet above the water.  Also, I can see the two backstay connections...looks like if that piece of aluminum was not there, you could pull the stemballs out thru the top of the casting (one is partially sticking out).  Thanks for posting.

I will be replacing my main halyard sheave with a ball-bearing unit (its the only one that sees use).  But, I think that can wait for the next time I pull the stick.   Looks like that would be difficult to do at the top of the mast.


Allen W.
 

Can anyone comment on changing sheaves with the mast up?
There have been a few comments about replacing Masthead Sheaves being easy, but I’m not sure if they were talking about with the mast up/in place, or when it was taken off the boat during winter.
 
I sent a drone up to take a few pics and I don’t seem to have the 2-screw cover other people have.
 
I looked up the masthead on the Sparcraft website, and it looks like I have the 
MAST HEAD RIG - TAPERED as can be found HERE.
 
It looks like the Masthead Rig has a welded top and the entire thing is a cap.
I’m not sure of some of you have knocked the axle out in place (with the mast up)
or if you’ve waited until your mast is down and then removed the cap like Keith Sugg #100 did.


Allen W.
 

Here’s a pic of my masthead taken with my drone,
as well as an EXCELLENT photo showing my drone piloting skills…
which are almost as good as my sailing skills...






4speedfunk
 

I can see this thread going all wonky because I think we are talking about several different mastheads.  My MkI (#096) has a Z-spar masthead and it looks like Keith’s (#100).

Allen’s Sparcraft masthead is definitely a different design.  Also it looks like the upper shrouds attach directly to the mast, while on the Z-spar they pass thru a window in the mast and are attached at the very top of the casting with eye fittings.

Sailboats are probably responsible for more drone crashes than any other object.  Ouch!


Tom Sokoloski
 

Allen, 
I'm 99% sure that you do NOT have a tapered mast. Your mast looks similar to mine, and in keeping with CY philosophies, they would have installed a straight, sturdy, no-frills mast. I haven't studied my masthead in quite a while, but in looking at your pix, unless you can attach a substitute forestay and backstay (below the masthead), and disconnect the forestay and backstay, I'm guessing you will have to wait until you unstep the mast to replace the sheaves. But.....I've been wrong many times before!

Tom Soko
Juniper #307
Noank, CT

Bummer about the drone. I crashed mine into the side of our house, but it survived with only a few scratches. 

--
Tom Soko
Juniper #307
Noank, CT


Allen W.
 

I think you're right Tom, I don't think it's tapered.  But I don't seem to have the Masthead Cap access plate like some boat do.

I went up the mast over the weekend.  It looks like the aft sheaves can be replaced with the mast up.
But I seem to have the same situation as Keith #100.  His photo showing the 'too small' sheave is the same thing I'm experiencing.
The 'too small' sheave doesn't seem to be wide enough for a 1/2" halyard.

Unless I can find someone with their mast down that's willing to send me they OEM removed sheaves,
I'll have to have a rigger come out, take the OEM sheaves to Garhauer (who is nearby my house),
wait for them to make a set, and then have a rigger return to install the new Garhauer sheaves.

attached photos show:

  • Aft masthead cap and Sheave Axle with cotter pin and access to replace with mast up.

  • Straight on view of OEM sheaves (note: axle cotter pin, starboard side).

  • Rough comparison of new 'too small' sheave compared to OEM sheave.
    (Note:  the new sheave is closer to the camera.  It appears a bit bigger due to the camera angle)


- ALLEN

C400, 1999 Mk1, #154 San Diego, Ca








 




Tom Sokoloski
 

Allen,
The pic you sent with the new and old sheaves together is tough to judge, as they are 90 degrees to each other. Did you try placing the 1/2" halyard in the new sheave at the deck to see if the line fits or not?  Also, the last foot or so of the halyard (near the shackle) is larger because of the splice. If the new sheave definitely doesn't fit (maybe it was made for 7/16" halyards?), then you should go back to Garhauer with your problem (especially if they are near you!!!), and I'm sure they can come up with something easily. I don't think you need to take your OEM sheaves to Garhauer to duplicate them. They REALLY know Catalinas. If you explain that the sheave they sent you looks like it is for another model, they might just pull the correct sheaves out of a parts bin and you can be on your way. You should have an accurate measurement of the sheave diameter, line diameter (1/2"), and hole/pin diameter. 

Tom Soko

--
Tom Soko
Juniper #307
Noank, CT


Allen W.
 

Hi Tom. Yes, tested the sheave width with a 3 month old 1/2” line on the deck before going up.
At the factory, they also gave me a wider sheave that likely is too wide for the slot.
They said the one they gave me should be the max width that would fit, but there are quite a few masthead cap configurations out there, as well as a possible documentation error someplace.
 
A friend just mentioned to me the Catalina Direct OEM style Plastic sheaves that I’m sure aren’t make by Garhauer.  I’m going to measure the ’too skinny’ sheaves and compare to the plastic specs off Catalina Direct.
 
 
BIG mistake on my part is not taking calipers up the mast with me... 


Allen W.
 

Found a discrepancy between the plastic and ball bearing sheaves on Catalina Direct.
 
From the listed specs, it looks like the Plastic Sheaves are:
 
1/8”  larger diameter and
1/16”  larger width
 
I’m not sure if 1/16” is enough to accommodate the 1/2” line, but likely better than the skinny sheaves.
I’d still like to have my old one out for comparison.

 
from Catalina Direct:
 
Plastic Sheave dimensions:
 
• Outside diameter:  3-3/8”  (LARGER on Plastic Sheaves)
• Inside diameter:          7/8”     (likely different due to generic bushing kit)
• Width:                          5/8”     (LARGER on Plastic Sheaves)

 
Ball Bearing Sheave dimensions:
 
• Outside diameter:   3-1/4” (different from Plastic sheave)
• Inside diameter:     1/2"
• Width:                     9/16”   (different from Plastic sheave)


keithsugg@sbcglobal.net
 

For what it’s worth… I have replaced my standard double braid halyards with New England Ropes VPC lines.  Not too exotic or ridiculously expensive, lighter so less weight aloft, and still stronger even at a smaller diameter. Could solve the issue of the sheave fitting the halyard diameter. 
Keith


On Apr 7, 2022, at 12:13 PM, Allen W. <wrenchaw@...> wrote:


Hi Tom. Yes, tested the sheave width with a 3 month old 1/2” line on the deck before going up.
At the factory, they also gave me a wider sheave that likely is too wide for the slot.
They said the one they gave me should be the max width that would fit, but there are quite a few masthead cap configurations out there, as well as a possible documentation error someplace.
 
A friend just mentioned to me the Catalina Direct OEM style Plastic sheaves that I’m sure aren’t make by Garhauer.  I’m going to measure the ’too skinny’ sheaves and compare to the plastic specs off Catalina Direct.
 
 
BIG mistake on my part is not taking calipers up the mast with me...