200 amp alternator nut size

[erasedhammer]

I read the instructions sent with it, and it says to reuse the nut from the 60 amp alternator, but I tried to fit that nut on and it was too small. 60 amp alt nut seemed to be 3/4 16 but the shaft on the 200 seems to be 7/8 in diameter.
Anyone know the actual nut size?

Also the pulley seems to be a solid inch off of the other pulleys, which then would require a spacer between the pulley and alternator. But to do that I would need to grind down the woodruff key to fit such a thick spacer. I don't think this was how AM general intended it to work?

Here are all the pictures that I took. I took some of when the pulley was flat against the alternator, and the others with the pulley properly aligned, and when it is aligned it leaves about a 1/4 of space between the two.



I just checked the epay listing where I bought the alternator and its the N1225-1

 

[Wire Fox]

What's the make and model of your 200 Amp alternator? I'd like to assume you're using an N1225-2.

Looking at TM 9-2320-280-24P vol 1, section 38-1 (A2 application), I pulled that the pulley nut is MS21245-L12, a self-locking nut. If we look at the later section, 40-1 (A1/Original application), we see that same application shows part number N9416, which fortunately turns up the same specs. Data from Parttarget confirms that it is a prevailing torque all-metal nut and shows that this is a 3/4-16 nut: http://www.parttarget.com/5310-00-4...choption=nsn&originalsearchtext=5310004190876

I can't visualize the issue you're having with the spacer. Do you have any photos of what's going on and can you also confirm which alternator you have?

Edit: Removed bad info.

 

[Retiredwarhorses]

You need a 200amp gen mount for the 200amp generator, the long bolt is 7/16 fine thread or course thread.
nothing is required to be ground down, it's plug and play, I assume you have the install instructions provided in the 200amp install kit?
You don't reuse any of the hardware from the 60amp to mount the 200amp mount or Gen, all new hardware is included in the kit.

 

[erasedhammer]

You need a 200amp gen mount for the 200amp generator, the long bolt is 7/16 fine thread or course thread.
nothing is required to be ground down, it's plug and play, I assume you have the install instructions provided in the 200amp install kit?
You don't reuse any of the hardware from the 60amp to mount the 200amp mount or Gen, all new hardware is included in the kit.

The kit I got did not come with a nut or spacer and the instructions and drawings I got were directly from AM General. This is the nut for the pulley shaft

 

[Retiredwarhorses]

The kit I got did not come with a nut or spacer and the instructions and drawings I got were directly from AM General. This is the nut for the pulley shaft

you might want to post some pics up of what you have....I've done this conversion a lot and never had any issues.

 

[TedG]

A serpentine pulley is secured completely different than a v belt. Which are you using? The kit I have is for v belt. Complete and all parts included. E_ay has them.

 

[erasedhammer]

you might want to post some pics up of what you have....I've done this conversion a lot and never had any issues.

I'll update the main post with pics. I took a couple pictures of the pulley flat against the alternator, and with the pulley properly aligned with the other pulleys.

 

[mechanicjim]

the N9614 number is a Niehoff part number here is the nut and washer for the pulley Niehoff doesn't have a listing for the pulley # as it was supplied separately. N9416 1 Locknut (3/4-16 UNJF-3B)
N9393 1 Flat Washer (.77" ID x 1.31" OD x .09" T)

 

[erasedhammer]

the N9614 number is a Niehoff part number here is the nut and washer for the pulley Niehoff doesn't have a listing for the pulley # as it was supplied separately. N9416 1 Locknut (3/4-16 UNJF-3B)
N9393 1 Flat Washer (.77" ID x 1.31" OD x .09" T)

Yep. Except now the belts are apparently too short, but I can't take the belts off because there's a hose connected to the fan hub and the belts won't stretch either. So I am forced to disassemble the fan hub to take the shorter v belts off. I can't believe what a stupid desigb this is, one where you need to take off the hub to the fan to take a belt off...

 

[DainGerous]

TM says for 200A gen the nut is 3/4-20 self locking NSN 5310004190876 P/N MS21245-L12, Washer NSN 5310007720442 P/N 7720442.

 

[erasedhammer]

TM says for 200A gen the nut is 3/4-20 self locking NSN 5310004190876 P/N MS21245-L12, Washer NSN 5310007720442 P/N 7720442.

A 3/4 16 worked for me.

 

[Retiredwarhorses]

I don't believe it's a coarse thread...

 

[erasedhammer]

I don't believe it's a coarse thread...

The 24p says it's 3/4 16 for the 200 amp

 

[Retiredwarhorses]

3/4-16 is fine thread

 

[Wire Fox]

Resurrecting this thing out of some frustration myself... It's definitely a 3/4-16 locking nut. By spec, it's an all-metal prevailing torque nut, but the caveat: the nut can't be taller than 0.406 in. I can't find a nut like this on any part site, and my alternator didn't come with one. I've got email feelers out to CE Niehoff and to a general fastener supply house, but if there's any place that has them openly listed, I'd really appreciate it, as it's nice to get to see a price...

 

[86humv]

Kascar has it.
MS21245-L12

 

[erasedhammer]

Resurrecting this thing out of some frustration myself... It's definitely a 3/4-16 locking nut. By spec, it's an all-metal prevailing torque nut, but the caveat: the nut can't be taller than 0.406 in. I can't find a nut like this on any part site, and my alternator didn't come with one. I've got email feelers out to CE Niehoff and to a general fastener supply house, but if there's any place that has them openly listed, I'd really appreciate it, as it's nice to get to see a price...

I got mine from Zoro

https://www.zoro.com/value-brand-jam-nut-34-16-gr-a-zp-pk10-u113700750001/i/G3319298/

fits perfect, I couldn't tighten it to the full 120 ft/lbs or torque, but I've been driving around for a month or so now and no problems. For my 200 amp I had to use a spacer, which I also got from zoro.

 

[86humv]

Watch out using sub standard hardware....That Zorro nut is Grade A which is not even close to the proper grade 8 like the MS21245-L12 lock nut.
That grade A nut is a jam nut w/o a locking feature.
And the max torque is way less due to soft steel.

 

[Action]

fastenal

 

[Wire Fox]

Kascar has it.
MS21245-L12

Well heck, I searched that exact P/N on Kascar last night and didn't see it. I must have typed something wrong and missed it. Thanks for pointing that out. I wish I knew that I needed this thing when I just placed an order last week with them. My next planned order was going to be some bigger dollars in buying some of the remaining electronics I need for the 4L80E...