New Alternator Problem

dactura

Member
I put a new alternator on the 8N, but have a mechanical problem. The guys at Napa auto parts swapped the pulley so I could put on the tractor pulley. They told me that they could not tighten it because they didn't have an allen wrench. This seemed odd to me, because the port in the center used to hold the axle was one of those torex fittings. No problem, I have them and tightened the new pulley. Then I installed the alternator on the tractor and started it up.

After a short while, it began to scream. That fan thing on the alternator was not tight against the axle. I turned it off and tightened the nut more... and then stripped the torex fitting. The fan thing still spins freely... and screams.

I am no longer a fan of torex fittings.

I have two questions:

1.) Is that fan thing really necessary?
2.) How will I ever get the nut off so I can fix the fan?

9207.jpg
 
(quoted from post at 07:02:01 01/18/18)
You have the wrong pulley and the wrong belt...
You need a 98-NAA5825 pulley.
You can keep what you have its always going to be a problem and never fully charge the battery as it should be... BTDT a pulley is cheaper than buying battery's...

http://forums.yesterdaystractors.com/viewtopic.php?t=1326598&highlight=pulley

You are God's angle Hobo! Your help in getting the electrical straightened out has given me years of faultless ignition. I have no idea how you can look at that photo and know the pulley is wrong - but I do know you have high level healing powers for the 8n, so I've ordered the pulley.

The linked belt on the tractor is 5/8". https://www.amazon.com/gp/product/B006SJK3V8/ref=oh_aui_search_detailpage?ie=UTF8&psc=1 It has worked well for over two years. I read most all of the debates about the use of linked belts. I opted for the linked belt because it's easy to install and it allows for "wobble". I do not know why, but there is a slight wobble in all the pulleys. It may likely be the alternator setup.

I read that to install a new belt (conventional belt) I have to remove the water pump. I believe that involves taking off the hood assembly, gas tank and all of that - which I really don't want to do.

BTW, I thought my battery was going dead all the time because of parasitic discharge. I read the articles on this forum on the subject and carefully playing with my meter (I hardly understand how the thing works) I was able to find the problem. I've had the new alternator on for several days and have been delighted to see that when I'm done with my tractor ride the voltmeter ( I think you suggested dumping the amp meter for a voltmeter... or some guru) shows a slight increase in voltage rather than my typical decrease! After my latest charge of the battery I decided to try out the "Is the alternator bad?" feature to discover the alternator is bad.
 
(quoted from post at 10:56:57 01/18/18 )

I read that to install a new belt (conventional belt) I have to remove the water pump. I believe that involves taking off the hood assembly, gas tank and all of that - which I really don't want to do.

i know we put a new belt on mine without removing the hood. i'm trying to find out if the guy who helped me remembers any more details. i do know for sure that we did not remove the water pump.
 
Dactura,

What hD6gTom said about the shim seemed perfectly or [i:b1c6e45d17]painfully [/i:b1c6e45d17] obvious! :)
 
(quoted from post at 11:47:52 01/18/18) Dactura,

What hD6gTom said about the shim seemed perfectly or [i:ea87f18db7]painfully [/i:ea87f18db7] obvious! :)

Yes, in retrospect, I probably should not have trusted the guys at napa but took the nut off and looked at how things went together. I ran the tractor yesterday and it didn't scream so I didn't work on it... but I suppose I will have to get to it sooner or later. It's raining today, so it's going to be later.

I don't know how important that little fan thing is. No one seems to have an opinion; but if they put it on, I suppose it was for a better reason than marketing, so I won't just take it off and toss it.
 
(quoted from post at 14:15:13 01/18/18)
(quoted from post at 11:47:52 01/18/18) Dactura,

What hD6gTom said about the shim seemed perfectly or [i:e7a3bdaeae]painfully [/i:e7a3bdaeae] obvious! :)

Yes, in retrospect, I probably should not have trusted the guys at napa but took the nut off and looked at how things went together. I ran the tractor yesterday and it didn't scream so I didn't work on it... but I suppose I will have to get to it sooner or later. It's raining today, so it's going to be later.

I don't know how important that little fan thing is. No one seems to have an opinion; but if they put it on, I suppose it was for a better reason than marketing, so I won't just take it off and toss it.


The fan is for cooling cause like all things friction inducing, heat is a primary debilitating factor shortening component life. Might even help with the armature's running balance. :)
 
P.S.
More importantly current produces heat of course and excessive current = excessive heat detrimental to windings etc.
 
dactora,

By the way, there's nothing exotic about the "shim",
it's just a very thin washer.

T
 
(quoted from post at 14:45:25 01/18/18) dactora,

By the way, there's nothing exotic about the "shim",
it's just a very thin washer.

T

Yeah... :) a $5 word for a 50 cent idea: thin washer.
 

I ran a N for years with out a fan on the alt it also had the same pulley you have. It uses a spacer behind the fan and one between the fan and pulley. Its a selective process to get it set up correctly are you can use different width spacers to move the pulley in and out. That's why I have thru the years saved every spacer out alternators.

I started to have low weak battery issues so put a new battery in it. A few weeks later the same deal. I then got down and dirty checking it out the belt was slipping on the pulley. With a new pulley and new belt it worked out well after the belt wore are the pulley the belt road to low in the pulley not truing the alt as it should.

If It had had a fan on it I could have just pushed on the fan and know the belt was slipping even tho the belt was tight... I then ordered up the pulley in my post and put the fan back on it that ended my charging system issues...

Link belt I guess it has its place but not on a alternator... I don't understand why you cannot put a regulay belt on it...
 
(quoted from post at 15:53:52 01/18/18)
(quoted from post at 14:45:25 01/18/18) dactora,

By the way, there's nothing exotic about the "shim",
it's just a very thin washer.

T

Yeah... :) a $5 word for a 50 cent idea: thin washer.

Not really just a washer..
Tom was right in calling it a shim.
I was just explaining to you that it looks like a washer.
A big washer with a big hole wouldn't naturally be paper thin.

I have a big jar in my shop, marked "[b:93419b9c41]Special Washers[/b:93419b9c41]".
that's the first place I'd be searching if I needed a pulley shim.
 
Thanks guys!

JMOR's suggestion of the impact wrench worked like a charm in taking the nut off and then putting it back on. It didn't spin. For me, magic!

Hobo's suggestion of using the right pulley worked wonders! The belt doesn't slip anymore - and the fat shim that came with it allowed me to tighten up the fan so that there is no slipping and I get a nice charge on the battery each time I use the tractor. Nice!
 

Back in the early 80's A guy stopped by with a charging system issue on a ford Granada he had replaced everything starting first with the alternator. I did not fix it I tried my best on a Saturday about quieting time I told him he would have to leave it that was a no-go, He stopped by one day to tell me the fix. The pulley was not thigh on the alt the fix a impact gun... Its funny how you don't forget chit like this just encase you run across another one but that has been a no-go but I am still not giving up hope...
 

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