Replacing alternator on Case 580k - do i remove the fan belt wheel ?

rdavison39 · Jun 20, 2020

Hi there - i've attached a picture of the alternator that i just removed from my case 580k.

I'm looking on amazon for a rebuilt one (btw, any opinions on this?).

My question is I am assuming that i need to remove the wheel that the fan belt would wrap around and turn. I did try to remove the centre bolt but its not coming off easy as the fan belt wheel is turning in the vice. I don't want to ruin the fan belt wheel by crushing it in the vice so asking if this would normally come with a new alternator or if I'm expected to remove and put on the alternator. Thx in advance

mitch504 · Jun 20, 2020

Never tried Amazon for a rebuilt alternator.

It depends on the alternator you get whether you have to change the pulley. I would just wrap a rag around it and use an impact wrench, but if you don't have one, I think you can stick an Allen wrench in the end of the shaft. If you stop by about any auto shop they ought to knock that nut loose in 30 seconds

rdavison39 · Jun 21, 2020

Thanks Mitch - i was able to get the nut off with the impact wrench as you suggested. The pulley doesn't exactly slip off. I've tried prying it off with a screwdriver but it isn't budgeting. Before I go all out I was wondering if this pully is threaded so i have to "unscrew it" as well or if its just an arbor and it *should* slip off albeit with some force given its probably got some dirt and rust build up

DB2 · Jun 21, 2020

Has a tapered lock bushing. They can be tricky. Do you have an air hammer ?

Tinkerer · Jun 21, 2020

The pulley is pressed onto the shaft and it has either woodruff key or a straight key in the shaft.
There are special tools to remove the pulley.
Purchase your alternator from a vendor that sells them with the pulley on it. Most do. Any auto parts store will likely have one.
Yours looks damaged already.

rdavison39 · Jun 21, 2020

Hi - I do have an air hammer...but not sure what to do with it.

The fins are damaged because i was trying to remove the pully - but i think the pulley is intact. I do see a slot in the bushing that looks like you can insert something. I'm looking for alternator with pulley on it but don't see any.

edgephoto · Jun 21, 2020

Most alternators come without a pulley. Some you even have to change the clock position. Unless Case down something different than any automotive/light truck alternator I have seen in my nearly 40 years in the service business the shaft is not tapered. It uses a key. The slot you see is the keyway. Most likely your pulley and shaft have rust holding them together.

Good luck finding an alternator with the correct pulley on it from the aftermarket. Your best chance for that is the Case dealer. Even they probably swap the pulley over.

You damaged the fan on your alternator so you will need to replace that too. Why not bring the alternator to a rebuilder and let them rebuild yours. If you were hitting the shaft without the nut on it you may have done enough damage to the shaft that it is no good. You have damaged the core and many place won't give you credit since it is no longer fixable without replace the stator assembly.

A rebuilder will have pulleys, fan and can make that one working again.

DB2 · Jun 21, 2020

This is what I think it has. The shaft is straight but it uses a tapered bushing in the pulley.

If it’s in fact the case I screw the nut back on flush and hammer on the face of the pulley until it separates .

I agree with the others that you should find a shop that does them for a living.

edgephoto · Jun 21, 2020

That style pulley is different than anything I have dealt with. I would do exactly as described above. Thread the nut on loosely and hit the pulley. It should pop off.

I do not mean any disrespect but take it to a shop before you do any more damage.

are you positive the alternator is the issue?

DB2 · Jun 21, 2020

Was popular on Cummins with serpentine belts for what ever reason. Maybe to support the extra width of the pulley due to the belt? Can be stuck pretty tight sometimes.

rdavison39 · Jun 21, 2020

Thanks for the help guys. Sorry for what is probably a naive question but just trying to understand why I would thread the nut on loosely and then hit the pulley - why wouldn't i leave the nut off ?

DB2 · Jun 21, 2020

It depends on how you support things but for me it’s just so the alternator doesn’t go flying.

Tinkerer · Jun 21, 2020

The Case parts book shows four variations of alternators for the 580k's.
Depending on which model k you have.
You do have the tapered bushing and like the one in your image you posted. Also a woodruff key, not a straight one
https://partstore.casece.com/us/par...3e458ad0&sl=EN&currency=#epc::mr54946ar957937

melben · Jun 21, 2020

Just take a punch that will fit outside the center wedge and hit it a couple smacks with a hammer and it will loosen up and the wedge will slide off, not keys to worry about, put it on the new alternator and use an impact and tighten it holding the pulley as another suggested, very easy have changed dozens.

yamiacaveman · Nov 19, 2020

Hey melben, do you mean to put the punch on the Pulley and wack it a bit. I'm just confused about your "center wedge" from the diagram above is that part 28?
I'm not there yet but have a feeling I will be doing this in the near future.

Thanks for any help.

melben · Nov 19, 2020

Yes, outside of the slotted piece, as pictured it is a wedge and as soon as you knock it loose from the pulley the wedge will slide right off. Maybe you could get a socket that will fit in there without contacting the center wedge and hit on it instead of a punch, they do not come off hard at all.

yamiacaveman · Nov 19, 2020

Thanks, when the time comes I will give it a try.

melben · Nov 25, 2020

yes, the pulley just takes a little shock to let the wedge separate from it, the wedge when released will slide right off. You could probably drive something into the slot in the wedge to expand it if it is rusted but I have never had to do that.

Replacing alternator on Case 580k - do i remove the fan belt wheel ?

rdavison39

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mitch504

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rdavison39

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DB2

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Tinkerer

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rdavison39

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edgephoto

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