Alternator re-assembly

Oct 26, 2008
6,311
Catalina 320 Barnegat, NJ
:( Ok, I'll be the first to admit that I take things apart and then have trouble putting them back together because I always think it looks simple enough that I can remember the procedure! Then I find out I can't exactly remember! In this case, I'm pretty sure it went back together the right way but I have one nagging concern.

Alt diagram.jpg


I attached the curved bracket at the bottom of the alternator and closed that pivot stud finger tight to make it seat firmly against the engine part. Then I pivoted both the alternator and the bracket, expecting them to mate snugly. Instead, the bracket wouldn't cleat the flange of the alternator and I couldn't make the bracket mate with the hole for the bracket stud. I could swear that was the way it was put together (the only thing I wasn't sure about was whether the bracket stud was installed with the head on the front side and the nut on the backside or vice versa). I spent a lot of time trying to figure out if the bracket was mounted in some other way, but all my conclusions pointed to the way I have it.

The only way to make it fit was to loosen the bracket pivot stud a little so that there would be enough play in the bracket to get it to clear behind the alternator flange. Eventually, that's the way I put it together and then just tightened everything down. It's all very snug and tidy, but I am left wondering if that mismatch was intentional so that there would be compression on the two parts as the studs were tightened down or if I missed something that would make the fit more exact. You can't see the curved part of the bracket in the photo as it is behind the alternator flange. Sorry if my part descriptions aren't technically correct!

Reason's why I loosened my alternator:
1. The belt loosened and I had belt dust all over. I changed the belt.
2. I had to get access to the negative stud to install a new cable going back to the negative bus bar. In the meantime, @Maine Sail (and others) suggested that I shouldn't have 4 AWG cables attached to the alternator studs, so I installed 6 AWG cable running to the top of the compartment. From there, I will run the 4 AWG cables that I already have.
3. I installed a new washer that hopefully will provide a better grip on the alternator bracket. The original washer was significantly thicker than a normal washer, but this new "Grip-it" washer should provide a better grip hopefully!

Finally, with everything in place, with covers in place!

Alt cover.jpg
 

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capta

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Jun 4, 2009
4,956
Pearson 530 Admiralty Bay, Bequia SVG
Your phone or digital camera is your very best friend when you are disassembling things. Especially those you don't do often, but those you do often as well.. Start a scrap book.
 

DArcy

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Feb 11, 2017
1,773
Islander Freeport 36 Ottawa
I'm just wondering if the "thick washer" on the "Alternator pivot stud" is on the right side of the bracket. Moving it to the other side might give you the clearance you need. It really shouldn't be forced together.
And yes, take photos while disassembling! I take lots when taking things apart and they often come in handy when putting stuff back together.
 
Oct 26, 2008
6,311
Catalina 320 Barnegat, NJ
I'm just wondering if the "thick washer" on the "Alternator pivot stud" is on the right side of the bracket. Moving it to the other side might give you the clearance you need. It really shouldn't be forced together.
And yes, take photos while disassembling! I take lots when taking things apart and they often come in handy when putting stuff back together.
I did think about that but it can't be the case. First, the bracket has an offset to the rear side of the alternator and it doesn't make sense that it would have that offset and still be set to the front side. It would need a spacer that is at least an inch thick, and I know there wasn't anything like a spacer of that size. Secondly there were only 2 thickened washers and they only fit the alternator studs. There was no other place to put them. The hole size isn't large enough to fit the bracket pivot stud. I accounted for all the studs, washers and nuts and didn't lose any parts. I agree that it doesn't seem like it should be forced together. But I recall that I did have to take out both the bracket stud and the bracket pivot stud in order to move the alternator. I couldn't get it to pivot until I loosened and removed those studs, so it must have had pressure binding the two parts together. When I think about it, the way that it was put together and tightened, the pressure should discourage the alternator from pivoting and loosening. I still can't help but feel that something was off, though, but I don't see it so far.
 

Ward H

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Nov 7, 2011
3,795
Catalina 30 Mk II Cedar Creek, Bayville NJ
@Scott T-Bird
The thick Grip It washer goes at the slotted end of the alt bracket, under the bolt head. It should be in front of the bracket helping the bolt to clamp the slotted adjustment bracket to the block or what ever is behind the alt bracket. You don’t need it at the pivot bolt or at the end of the bracket where there is just a hole, not a slot.
How‘s the pulley alignment? I would guess a new thick washer, the Grip It washer, being placed under the bracket would throw it out of alignment or bend the bracket out of alignment.
 

NYSail

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Jan 6, 2006
3,148
Beneteau 423 Mt. Sinai, NY
I have to say, the yanmar covers look real nice however on my past two boats that was the first thing I removed. They make it a pain in the neck to check anything......I like instant gratification when I look at how she is running and I tend to check often.
In regards to your install, how does she run? You will find our real quickly as a little misalignment and the engine will scream and let you know and/or the belt will dust. I would take the cover off and observe. Washers are typically intentionally put on the brackets in different sizes to assist in alignment so using the previous washer set-up may be important.

Good luck!
Greg
 
Oct 26, 2008
6,311
Catalina 320 Barnegat, NJ
@Scott T-Bird
The thick Grip It washer goes at the slotted end of the alt bracket, under the bolt head. It should be in front of the bracket helping the bolt to clamp the slotted adjustment bracket to the block or what ever is behind the alt bracket. You don’t need it at the pivot bolt or at the end of the bracket where there is just a hole, not a slot.
How‘s the pulley alignment? I would guess a new thick washer, the Grip It washer, being placed under the bracket would throw it out of alignment or bend the bracket out of alignment.
Right, that is where the Grip it washer is installed ... at the back side of the bracket where the nut fastens to the bracket stud as shown in the picture. You can't see it behind the alternator. There is nothing between the back side of the alternator flange and the slotted end of the bracket. Those 2 faces are mated together with nothing in between.

When I initially pivoted the bracket and the alternator together for the hole to align with the slot, the bracket failed to clear the alternator flange by maybe just 1 or 1.5 mm - less than 1/16". The bracket is pretty rigid so you can't simply bend it into place by hand. That's why I had to loosen the bracket pivot stud (see photo) just enough to wiggle the bracket into place. With the alternator pivot stud in place (see photo) there is absolutely no way for the alternator to flex or move out of alignment. I'm guessing that the bracket must bend slightly (1 mm or so) for all the surfaces to mate properly when tightened with a wrench. My question is if this is intentional or not. There is no way to place the Grip it washer in any other location than the proper location without being grossly out of alignment.

I was only a little uncertain about the placement of the 2 thickened washers. They only fit the 2 studs that secure the alternator. You can see there is a cover bracket that is secured to the alternator pivot stud. This stud has a built-in spacer to offset the bracket. One thickened washer is used at the end of the spacer to bring the bracket in better alignment with the belt that it covers. The only other location where I could use the other thickened washer would be under the nut that secures the slotted end of the alternator bracket to the back of the flange on the alternator. This washer is now replaced with the even-more robust Grip it washer.

@NYSail I won't know how she runs until she is in the water, and I don't have any plans to put her in the water yet.
 
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Ward H

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Nov 7, 2011
3,795
Catalina 30 Mk II Cedar Creek, Bayville NJ
I'm sure you tried this but how about a washer on the bracket pivot stud to move the bracket forward the 1/16" of an inch?
Right, that is where the Grip it washer is installed ... at the back side of the bracket where the nut fastens to the bracket stud as shown in the picture. You can't see it behind the alternator. There is nothing between the back side of the alternator flange and the slotted end of the bracket. Those 2 faces are mated together with nothing in between.
That sounds right.

When I initially pivoted the bracket and the alternator together for the hole to align with the slot, the bracket failed to clear the alternator flange by maybe just 1 or 1.5 mm - less than 1/16". The bracket is pretty rigid so you can't simply bend it into place by hand. That's why I had to loosen the bracket pivot stud (see photo) just enough to wiggle the bracket into place. With the alternator pivot stud in place (see photo) there is absolutely no way for the alternator to flex or move out of alignment. I'm guessing that the bracket must bend slightly (1 mm or so) for all the surfaces to mate properly when tightened with a wrench. My question is if this is intentional or not. There is no way to place the Grip it washer in any other location than the proper location without being grossly out of alignment.
If the belt is tight, the pulleys are in alignment it sounds like you are good to go.

Do you run your engine before launch to make sure it starts? I use a 5 Gallon bucket with water and put the intake hose in the bucket.
I feel better knowing it will start when it hits the water.

I'm picking up the lug crimper today. I be down to the boat again on Friday and will get it to you.

'
 
Oct 29, 2005
2,363
Hunter Marine 326 303 Singapore
You know how car workshop collect so much spare bolts and nuts? There's always something left behind after work is done. If it still work after box up, toss the remainers in the collection bin :)

Ken Y
 
Oct 26, 2008
6,311
Catalina 320 Barnegat, NJ
I'm sure you tried this but how about a washer on the bracket pivot stud to move the bracket forward the 1/16" of an inch?
No, because it needs to go back 1/16" but it can't. Putting a small washer in place would push the bracket forward and make it worse … and it wouldn't clear at all unless the bracket pivot bolt was really loosened and the bracket would then need to bend even more when all the studs are tightened. Remember, the bracket fits behind the alternator flange. It seems to be the only way possible.

Sue and I are coming down Saturday for sure. I don't know if I will get there on Friday or not, yet.