Alternator on B7100?

[Bluelick]

Hi All,
I have been thinking about winch options for my B7100. A logging winch running off the PTO would be great, but very expensive ($3000) for the amount I would use it. This gets me back to electric winches, but then I am stuck with the wimpy dynamo on the tractor. An alternator would relieve that issue and make it possible to add other electrical goodies (lights) also.

I have read about adding the Kubota alternator to other B-series tractors, but it seems it does not fit the B7100 and is pretty pricey at around $200 (OK, that's a lot less than the logging winch).

I saw mention of using an automotive alternator that might be small enough to fit in the engine compartment and could be a used item at the junk yard (now we're talking).

So, has anyone done this?

Many thanks!

 

[KennyV]

I posted this a couple years ago...
The least expensive would be to get a rebuilt Hitachi 14231 Alternator from NAPA, Advance Auto, Auto Zone or O'rilies. See if it will mount and fit. It should. If it does not they should have no problem with you returning it.
That little alternator is used in a lot of applications. I believe it was originally used in the 80's Nissan pickups. Has been used in a lot of Japan motors since. And many conversions.
It is an internally regulated 40 amp very affordable, very reliable, should be LESS than $50.00.
You can wire it as a single wire alternator if you want. So hook up is very simple. KennyV.

 

[Craig Clayton]

If your B7100 has a wimpy dynamo then the designed battery for the machine may not be the largest ( not sure )??. If you purchase a larger alternator and plan on running a winch,think of this. Mount a truck battery as part of the electric winch so the load will be supplied by the bigger battery, and the alternator only has to keep it supplied. They make battery isolator switchs for use when you do not want to drain the main battery.. When you are finished with the winching you switch back to the probably smaller onboard battery.
As KennyV suggested do not shop in the junk yard for electrical.
Craig Clayton

 

[Bluelick]

Thanks for the lead on the Hitachi alternator. I'd love to hear from anyone who has done this on a B7100 as far as the physical mounting in particular.

 

[Egon]

Does your B7100 have a freestanding alternator or the one that is integral with part of the water manifold?

 

[Bluelick]

Mine is an early B7100, around 1984. The dynamo is inside the housing that the fan is mounted to, connected to the water manifold.

 

[Egon]

That set up may need a little work to switch over as the fan has to be kept in operation.

 

[Bluelick]

I'm thinking that maybe the dynamo, and fan, can just stay there, but not be connected to the electrical system, and the alternator could go where the idler pulley is. Perhaps someone has done this?

 

[Craig Clayton]

That is a tight fit, so I guess the Big Block V 8 option is off the list. Lets look at the other places there may be a shaft, can you drive off the front of the engine, Rear pto ,mid PTO. Any big loads will kill the small alternator if it tries to keep up.
Craig Clayton

 

[Bluelick]

There is a splined shaft at the front of the engine, I've been curious about that. I believe it is a hollow tube with splines on the outside, seeming not so robust as a pto shaft. Anybody know what that's for?

 

[Craig Clayton]

That should be off the front of the crank shaft and operate at the same rpm as the engine. You could connect your atl from there but that could be a pile of work.
Craig Clayton

 

[LHoyer]

The small shaft on the front is the PTO and is used for running various implements. My snowblower runs off of this with an electric clutch. The problem with this shaft is that it takes a wierd spline that doesn't seem to be available from any current source. Many people have tried finding it. I think there is almost enough room where the idler is located, leaving everthing else intact and disconnecting the existing dynamo. Might have to run with the left engine side panel off though, to maximize room for the alternator.

 

[KubotainNH]

Mr. Paul added a power steering pump seen in the thread below. With a bit a modification you can add whatever you want.
http://www.tractorbynet.com/forums/kubota-owning-operating/104139-p-s-b7100-7200-a-5.html

 

[Bluelick]

I found this thread, which is from some time ago (2005), and the original poster seems to have not continued to participate on this board. He had installed a D850 motor in his B7100 to replace the original D750.

http://www.tractorbynet.com/forums/parts-repairs/56184-b7100-dynamo-alternator-change.html


From what he says, it seems that the timing cover from a d850 would fit on a d750 motor and then it would accommodate both an alternator and a water pump, which would be a nice thing also. However, he does not address the issue of fit within the engine compartment. He was mostly concerned with how to wire up the alternator with his existing harness. Interesting.