Alternator Pulley Shaft Size

[19963.4lsr5]

I'm sure the difference would be the same outcome as it is rpm based, I guess you could've tried the slightly larger 53mm pulley so it did'nt quite charge as much, Nothing wrong with charging at idle though, especially for my plow truck.

You mentioned a few numbers
157mm x 53mm, I think it's 15.7mm ID X 53mm OD x 14mm 4 rib belt width, it would make sense it would be 15.7mm ID to fit a 15mm alt shaft.

Do you no what the cold weather 80 amp Alt shaft size is off hand if someone tries to repeat what you have done. I think all the Canadian 4R's have the larger alt, I know my 99 has a 120amp Alt fuse under the hood.

I’m pretty sure it’s 17mm. I’m looking for a 17mm ID 48mm OD for my 80a.

All I have to do is just touch the gas and the voltage goes back to 14v.


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[Malcolm99]

I forgot you mentioned OEM is 53mm, sounds like the 50mm OD put you in the perfect spot especially if you run fogs and markers and a few other items. I think the 48mm OD would make it charge even more than you'd need/want.

Sounds like I might be looking for:
17.7mm ID x 50mm OD, x 14mm 4 rib

Thank you for the info!

 

[ArmArak]

Well I removed the pulley from my 70a Alt and got disappointed.

Shaft size is 15mm and I measured the pulley OD as 53mm. Plus it looks exactly like the picture I posted.

When I said the factory pulley is 55mm I was going by the specs on a website for a replacement Alt.

So I think my hopes are dashed. I haven’t found a 50mm pulley with a 15mm shaft size.


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Hey by any chance do you still have this old original pulley? If so could you please take a measurement of this diameter? I’m trying to machine an add on to drive my York compressor.

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[19963.4lsr5]

Factory pulley on the 70a Alt is 15ID and 53OD I do not have the belt offset measurement.


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[ArmArak]

Factory pulley on the 70a Alt is 15ID and 53OD I do not have the belt offset measurement.


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Do you know the diameter of the inset portion? I want my second pully backing to fit into that inset.

 

[Doc2012]

Do you know the diameter of the inset portion? I want my second pully backing to fit into that inset.

If you do this; let me know where you got the pulley from.

I have a York sitting in storage, and want to do the same thing.

I run CO2; but if I can add the York on there; that would be fantastic.


*edit to add:

Assuming this is going on a 3.4.

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[ArmArak]

If you do this; let me know where you got the pulley from.

I have a York sitting in storage, and want to do the same thing.

I run CO2; but if I can add the York on there; that would be fantastic.


*edit to add:

Assuming this is going on a 3.4.

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Yup its going on the 3.4. I might have to machine my own pulley if I cant find one to properly fit. Ill let you know how it goes.

 

[19963.4lsr5]

Yup its going on the 3.4. I might have to machine my own pulley if I cant find one to properly fit. Ill let you know how it goes.

I’ll get you your answer today.


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[19963.4lsr5]

Do you know the diameter of the inset portion? I want my second pully backing to fit into that inset.

43mm


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[19963.4lsr5]

Here is the pulley I bought it’s 50mm OD and 15mm ID.

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[ArmArak]

Not trying to steal the thread but I’m probably going to have to machine my own alternator pulley to work with my compressor. How important is the balance of the pulley? Will it be fine off a lathe or do I need to balance it after? My current pulley has some rust on it so I don’t think it’s very balanced right now as it is lol.


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[19963.4lsr5]

Not trying to steal the thread but I’m probably going to have to machine my own alternator pulley to work with my compressor. How important is the balance of the pulley? Will it be fine off a lathe or do I need to balance it after? My current pulley has some rust on it so I don’t think it’s very balanced right now as it is lol.


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My one all rusty also. If you make it on a lathe it should be fine.


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[ArmArak]

Factory pulley on the 70a Alt is 15ID and 53OD I do not have the belt offset measurement.


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Hi,

I think I can get this compressor thing to work but I'm not confident in my groove drawings. If you still have the old pulley and aren't using it can I have it? Ill pay for shipping of course.

 

[19963.4lsr5]

We can work something out. Pm me your address and I’ll do the same.


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[Doc2012]

Hi,

I think I can get this compressor thing to work but I'm not confident in my groove drawings. If you still have the old pulley and aren't using it can I have it? Ill pay for shipping of course.

Hey man.

Gonna PM you about this pulley/York thing.


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[19963.4lsr5]

As an update I also added a Hall effect amp meter.

Some amp specs:

Just running engine and radio 13a after driving 5 or so miles. Starts out at 21a after a cold start.

Headlights and fogs are 20a

Fan on speed 1 is 4a

Led brake lights are 1a.


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[_Ace_]

As an update I also added a Hall effect amp meter.

Some amp specs:

Just running engine and radio 13a after driving 5 or so miles. Starts out at 21a after a cold start.

Headlights and fogs are 20a

Fan on speed 1 is 4a

Led brake lights are 1a.


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So how did the pulley swap work out long term?

 

[19963.4lsr5]

So how did the pulley swap work out long term?

Still going strong. It will now push 44-45a at 600rpm.

I have an 80a I’m thinking about doing it too also.


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[brillo_76]

Still going strong. It will now push 44-45a at 600rpm.

I have an 80a I’m thinking about doing it too also.


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I think this is a super sensible mod. You fix the fan slow down at idle. Great Job and excellent news its stable long term.

 

[_Ace_]

Here is the pulley I bought it’s 50mm OD and 15mm ID.

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Will this fit an 80 amp OEM alternator?

I think that is what I have on my 1998.