M998 60 Amp to 200 Amp Alt upgrade?

[FlyingM9]

My 60 amp alternator in my 998 ate itself yesterday. After reading various posts I think I want to upgrade to the 200 amp dual voltage system. From what I can tell I need the 200 amp upgrade kit and of course the 200 amp alternator. Is their anything else that should be concerned about? Brands? NOS? or New or overhauled, bad serial number range of alternators etc?
Any help would be greatly appreciated.

 

[Retiredwarhorses]

None that im aware of...new and used 200amp will just be the price diff.
the ones I see refurb look brand new.

 

[hummer4x4guy]

Make sure it has the clutch pulley on it.

 

[Retiredwarhorses]

Make sure it has the clutch pulley on it.

clutch pulley only works on serpintine setup...and that clutch pulley assy is expensive as he**.
you will have use the pulley supplied in the upgrade kit.

 

[hummer4x4guy]

So if you install this upgrade kit without the clutch pulley doesn't one run into the possibility of snapping the shaft inside the alt?

 

[Retiredwarhorses]

There is no clutch setup for the v-belt setup...

 

[tomcata3]

I upgraded mine and use the 12v output to charge a 12v battery to lift my snowplow with my winch and run accessory's

 

[FlyingM9]

Thanks for the help. I will order everything tomorrow

 

[hummer4x4guy]

I KNOW you said there wasn't a clutch for the v belt set up. But the question of the possibility to break the alt still stands.

 

[Retiredwarhorses]

The problem is belt jump off, not breaking the gen...the first feeble attempt was adding a plate to the front of the PS pulley. I've never had the issue on any of of them...I have all 3 setups.

 

[kfrosty]

I just did this upgrade to my M998. I have a 6.2. What a PITA trying to get the 200 Amp in. Next time I'm going to use a engine hoist or something to where I can have straps to lower the alt into place. Trying to get the long bolt into the bottom along with the support bracket that mounts to the manifold as well as a wire support was trying. Have a helper.

Also, I didn't know about the metal tags on the wires. After figuring that out, everything seemed to be fine. The hot wire that used to go from the old alt to the starter, that goes on to the Ign post on the 200 amp alt. The two small wires you take out of your old alt. One is soldered onto the old alt, that wire goes on the Ign post of the 200 amp alt. The other wire goes on the accessory terminal.

What threw me off is I thought I wouldn't be using the old cable going from the alt to the starter. Once I figured out the numbers on the metal tabs on the wires then. (The numbers on mine had grease and dirt and had to wipe them off to figure out what they were.)

The kit I got off ebay came with belts, v pulley, everything I needed except for a female military wire connector to connect to the Ign wire in the trucks wiring harness.

 

[Mario]

Is this the kit that everyone is getting for about 61 bucks? http://www.ebay.com/itm/201602458146
Which Alternator are you guys buying and from where are you sourcing them?

 

[DLJIII]

I just ordered a 200amp 12 24v for my 1987 M998.
I just bought the truck and it would increase rpm and the alternator would start and slam the voltage into the high red line for 5 to 15 seconds each cycle.
It was recommended by a good guy here and this is what I bought, http://www.ebay.com/itm/122262064649?_trksid=p2060353.m1438.l2649&ssPageName=STRK:MEBIDX:IT
My question is pretty much the same, will this work and do I need a pulley or clutch for it?
I ordered the adapter kit, http://www.ebay.com/itm/282356988891?_trksid=p2060353.m2749.l2649&ssPageName=STRK:MEBIDX:IT
Is this everything I need to drop it in and run normally?
Thank you gents in advance and please understand I am brand new to this forum, these great vehicles and I am not a mechanic.
So please speak to me like a child haha.

 

[Outfitters]

I am not sure that N1228 alternator you bought on ebay has the same flange offset and shaft size/length as the HMMWV alternator N1225 since the N1228 appears to be for a different vehicle. I tried looking at ceniehoff.com but I couldn't find info on the N1228. Call niehoff and find out before you try to install it. The step by step instructions that come with the conversion kit are great just keep all the parts in the numbered bags until you need them. USE a hoist to lower the alternator in place.

 

[rhinob]

I did the 200 amp conversion with a refurbished alternator. I don't recommend lifting it into place by hand. Anyway, my heart dropped when it didn't charge, initially. Of course I then remembered to come off idle and check it and it works, and has worked, just fine since. I'd do it again.

 

[DLJIII]

I am not sure that N1228 alternator you bought on ebay has the same flange offset and shaft size/length as the HMMWV alternator N1225 since the N1228 appears to be for a different vehicle. I tried looking at ceniehoff.com but I couldn't find info on the N1228. Call niehoff and find out before you try to install it. The step by step instructions that come with the conversion kit are great just keep all the parts in the numbered bags until you need them. USE a hoist to lower the alternator in place.

Ok, I didnt realize there was a difference and the alternator should be delivered in a couple of days.
Yes this alt is for a M1074, a nice huge ten wheel vehicle.
http://farm4.static.flickr.com/3300/3262715660_d2d04b21a4.jpg
I will call niehoff and when I asked Osh on ebay before buying it, I didnt get a reply until after it was processed and shipped.
The only thing Osh said to my question was, "It may require modification."
So, that was very helpful haha.
Thank you.
Perhaps, I will get lucky and it will work and it can be a tested new approach with a less expensive unit.

 

[Wire Fox]

Ok, I didnt realize there was a difference and the alternator should be delivered in a couple of days.
Yes this alt is for a M1074, a nice huge ten wheel vehicle.
http://farm4.static.flickr.com/3300/3262715660_d2d04b21a4.jpg
I will call niehoff and when I asked Osh on ebay before buying it, I didnt get a reply until after it was processed and shipped.
The only thing Osh said to my question was, "It may require modification."
So, that was very helpful haha.
Thank you.
Perhaps, I will get lucky and it will work and it can be a tested new approach with a less expensive unit.

I made this same mistake and I've been trying to correct every copy of that mistake I've written on here so as not to mislead anyone. It will NOT work. The pulley shaft is too small and the pulley you try to install will have too much play. That without getting into anything with its actual function with the HMMWV charging system or the load it might place on the engine. That said...I have one of these for sale for less than what I paid for it... Maybe I'll get lucky one day and someone will need it, or I'll come across a generator with the right torque available that I can rig up a proper pulley onto and make use of this.

 

[DLJIII]

Thank you Wire Fox for giving me the definite answer even if it was not the answer I was hoping for.
The alternator should be delivered tomorrow and Oshkoshequipment does not offer returns.
So, I need to think of something because I have no use for the alternator and still need to buy a replacement.
It is weighing on me, all of these repairs and purchases to get my truck up to par is hitting me hard financially.
I am get to the crunch point after $1,500 much less buying another $500-600 alternator just to get my truck safely running.
Luckily, I ordered half axles and upgraded to 10k, service packs and everything else I need to get on the road.
Thanks again everyone, I do appreciate all of the help.
Oh check out my new grille guard too!
It is not done yet but, looking pretty good for a two evening project.
http://picpaste.com/pics/Yg2SJEeK.1490830418.jpg

 

[Mario]

Guys, I finally got to upgrading the 200A that I got from 86HUMV few month ago.

I have two questions:
1. the Reference wire that goes from 14V-Stud to Base.
I don't have that wire. What gauge do I use/need?
And... why is that needed? Doesn't that short 14V to ground?

2. What size gauge of wire do I need to take from new generator to secondary battery for the 12VDC accessory side of things?
Also, where does that wire on the generator? I would assume the it goes to the 14V stud, but since installation instructions are talking about grounding that post (see my 1st question), now I'm not sure.

TIA,
Mario

 

[Wire Fox]

Guys, I finally got to upgrading the 200A that I got from 86HUMV few month ago.

I have two questions:
1. the Reference wire that goes from 14V-Stud to Base. View attachment 692044
I don't have that wire. What gauge do I use/need?
And... why is that needed? Doesn't that short 14V to ground?

2. What size gauge of wire do I need to take from new generator to secondary battery for the 12VDC accessory side of things?
Also, where does that wire on the generator? I would assume the it goes to the 14V stud, but since installation instructions are talking about grounding that post (see my 1st question), now I'm not sure.

TIA,
Mario

Please ignore that wire on that drawing. Either leave it open (no wire connected, period), or run an 8 AWG wire back to the positive stud of the REAR battery in order to offer a 14V charging system (good for if you have multiple 12/14V accessories plugged in, to keep the batteries balanced). There's a technical guide at the CE Niehoff website that explains the correct way to make that connection, if needed.