Alternator Bracket

dlochner · Oct 8, 2022

Does this remain in place? If so how is it secured?

I installed a Balmar Belt Buddy last year and a slipping belt is no longer an issue.

Belt Buddy: UBB - Balmar

Belt Buddy Kit; Includes the Universal Adjustment Arm (UAA) and Belt Buddy Mechanism (BB). To utilize only the adjustment mechanism with an existing adjustment arm, purchase part number BBU. Caution: This approach sacrifices some “travel” in the existing adjustment arm so the BBU mechanism can...

balmar.net

sailcapt340 · Oct 8, 2022

I like your modification. It’s a much more practical device. No rush, but could you tell us the thickness of the bolted ends? My 2000 340 has a bent bracket adjusting arm for the alternator. It holds well, as slippage has never been a problem.
It‘s the adjusting that is an issue. I have to loosen the alternator front top bolt (12 mm), then open the side access panel in the aft compartment, then use a different socket (10 mm) attached to an extension arm, loosen that. Then back to the front of the engine, insert a screw driver in the slot, tension the belt, tighten the top front bolt of the alternator. Go back to the side access panel, switch sockets and tighten that bolt.
It’s a process. And I never get it right on the first try. And really, why 2 different size bolts?
I‘m not sure if your straight bracket would work for me given the thickness of it. But I love the “tie rod” style adjustable aspect of it. That’s for me. Thank you for your help.

dlochner · Oct 8, 2022

The attached photo shows an alternator jack I built a few years ago. Once the alternator is in close to the correct position, the jack will can increase the tension until it is correct and hold the alternator in position while the bolts are tightened. If the alternator is slipping, try using a double thick fender washer under the adjusting bolt head. This increases the friction and can reduce slippage.

Jack is made from a piece of scrap oak and ⅜" threaded rod. Once tensioned the jack is removed.

Tedd · Oct 8, 2022

dlochner said:
If the alternator is slipping, try using a double thick fender washer under the adjusting bolt head.

A "belleville" washer will also help resist loosening from the vibration.

dlochner · Oct 8, 2022

Tedd said:
A "belleville" washer will also help resist loosening from the vibration.

That would also work, the washer would keep tension on the threads. When I installed a new high output alternator I added a serpentine kit and the Balmar Belt Buddy. Easy to set the tension and it holds.

sailcapt340 · Oct 8, 2022

Dave, I like your idea. You’ve given me a nice rainy afternoon project. Thank you.

Tedd · Oct 8, 2022

It's easy to make your own adjustable link like the one in @RoyS 's picture, if you're so inclined, at least for a link to fit 3/8" bolts. It so happens that the inside diameter of 3/8" x 0.083" wall aluminum tubing is just about exactly the right size for 3/8 UNF thread. So, cut a piece of it to length, tap one end right hand and the other end left hand, thread a 3/8 x 3/8 rod end and jam nut in each end and you're ready to go.

Be sure to file the ends smooth and check perpendicularity to the axis using a square. Perpendicularity is important.

You can get everything you need from McMaster-Carr, including the taps. If you're thrifty, the "Economy Carbon Steel Taps" work fine in aluminum and are much less expensive. Or, you can get the material from Metal Supermarkets and the taps from any industrial supply house.

SycloneDriver · Oct 9, 2022

RoyS said:
Yes, remains in place. Secured by same fasteners that old contraption used. Old contraption was approximately 1/4” thick, while this device is 1/2” thick. You may want to use slightly longer fasteners. On my Yanmar all fasteners for the alternator and bracket are m8.

This is exactly what I need. My old adjuster are is too short with the new alternator and I could eliminate 1 spacer washer. They are easy to find 3/8 hole ends but not nearly as easy with 5/16. What did you use? Where did you get it?

SycloneDriver · Oct 10, 2022

RoyS said:
Caution SycloneDriver, your 5/16” fasteners may actually be m8 size as mine were. I searched for a local source but had no luck. Eventually I found a guy in England who supplies custom Heim joint adjustment rods. He has a Facebook page but I am not a user. He has an email address and is easy to work with. Payment through paypal. His email address is oilphiluk@yahoo.co.uk

You are correct, my fasteners are m8. I was just trying to simplify things, 5/16" m8 are very close.
I might just have a friend of mine make me some bushings and live with 3/8.

jaysweet · Oct 13, 2022

Tedd said:
A "belleville" washer will also help resist loosening from the vibration.

I bought a very thick, machined washer that Mainsail used to sell on his site, meant to solve this very problem. As I recall, he had them made specially for his business. It worked quite well to eliminate slippage.

I also use a standard belt jack that I inherited from my dad. It works great to set the tension, while you secure the bolts. Lots of people (including me) use a pry bar or mallet handle when the belt jack isn't handy.

dlochner · Oct 13, 2022

SycloneDriver said:
You are correct, my fasteners are m8. I was just trying to simplify things, 5/16" m8 are very close.
I might just have a friend of mine make me some bushings and live with 3/8.

Close but not close enough. Bad things happen when they are mixed up.

Richard19068 · Oct 13, 2022

dlochner said:
Close but not close enough. Bad things happen when they are mixed up.

I remember Mainesail / Compass Marine sold a sleeve you could use to to make a 3/8" bolt fit snugly in a 10mm hole. Used to adapt 3/8" mounting bracket to a 10mm alternator foot. Or was it the other way around? It worked well for mounting an alternator I got from him.

SycloneDriver · Oct 15, 2022

I measured the distance from center to center today I need to be able to shorten it down to at least 2 & 3/4 inches, max length of 3 & 1/2 should work. That's probably too tight for a 3/8 heim joint, so I'll have to find 5/16" or 8mm.