Removing/Replacing Pulley Nut -- School Bus Alternator

[Dockhead]

What I thought was bad bearings on my alternator turns out to be a loose pulley nut, which allowed the fan to meet the housing, destroying the fan. Otherwise the alternator seems to be fine. So could be that all I need is an $8 fan.

But I can't figure out how to get the pulley nut off. The shaft can't be locked from the other side as it doesn't even stick out.

Anybody know how it's done?

[Fiveslide]

Impact wrench, don't try to lock the shaft, that should spin it off. Put the new one on with the same impact wrench. Happened to me on a cummins

[Dockhead]

Originally Posted by Fiveslide

Impact wrench. Put the new one on with the same impact wrench. Happened to me on a cummins

Thanks. And I do have an impact wrench on board. And how to get the old one off? Is there any way to hold the rotor shaft?

[a64pilot]

Leave alt installed with the belt tight

[Sailmonkey]

Is there an Allen socket cut into the shaft? I've run across this a few times where I needed to weld a pass through handle onto a socket so I could turn the nut while holding the shaft with an Allen wrench

[Dockhead]

Originally Posted by a64pilot

Leave alt installed with the belt tight

Aha!!!

Too bad we don't have a "light bulb going off over the head" smiley.

Thanks!!!

[Fiveslide]

Originally Posted by Dockhead

Thanks. And I do have an impact wrench on board. And how to get the old one off? Is there any way to hold the rotor shaft?

I didn't have to lock the shaft. Impact spun the nut off and back on. The belt idea is a good one, too.

[wayne.b]

Originally Posted by a64pilot

Leave alt installed with the belt tight

===

That's how I do it.

[kenbo]

Dockhead,

You have a pneumatic impact wrench on board???

[Siberian Sea]

Electric impact wrench, works great

[deblen]

https://www.harborfreight.com/12-in-...nch-68099.html

https://www.youtube.com/watch?v=T3Mn9QFurwY

[Dockhead]

Originally Posted by kenbo

Dockhead,

You have a pneumatic impact wrench on board???

Ha, ha. No. I have almost everything else, though, including a drill press

I have a HAND impact wrench. Were people talking about pneumatic ones?

[Dockhead]

Originally Posted by deblen

https://www.harborfreight.com/12-in-...nch-68099.html

Thank you!!

[a64pilot]

Pneumatics are in my opinion much better, and inexpensive.
If you have a compressor for a Hooka, why not pneumatic tools?

[Fiveslide]

Originally Posted by Dockhead

Were people talking about pneumatic ones?

I was. Hand impact might work, it will certainly take longer.