Niehoff alternator question

[rickndani1710]

Hello, looking to see if there is a rebuild kit or a cheaper alternative to replacing the alternator. Small volunteer fire department. LMTV? 1078 with a CAT 3116 Niehoff 100 amp, 14/28 volt 1506-1.

 

[Ronmar]

They only release parts to their dealers/overhaulers. lots of opinions on this, here is mine:

Replace it with a straight 24V alternator like a Delco 110A@24V alt. Use a Victron Orion 24-12 converter to provide 12V@70A for the vehicle. one or 2 other small mods will make this a solid power system. All this is doable at significantly reduced cost(1/2 or less) from what you will typically find a replacement dual volt Neihoff costing...

The existing alt bracket can be modified to accept a J180 mount Delco alt. This mod is fairly easy depending on your available skills(basic metal fab, basic electrical). This builds the power system around commonly available and repairable components(Delco and Victron can be sourced about anywhere).

Based on how the dual volt creates power, this straight 24V alt change also increases available power output by ~33%...

My .02

 

[GeneralDisorder]

There's basically nothing to rebuild. All the stuff that could have "failed" is very non-trivially potted and what's left is windings and that would require a motor/generator rewind shop which is not likely to be economical. It's also a NASTY process best left for industrial settings and applications where the parts are 10's or 100's of thousands of $$$$. The Niehoff distributors/repair shops can only order assemblies - end bells with potted electronics, rotors, stators, voltage regulators, etc.

That said, the 100 amp Niehoff units were not reliable long-term and I would suggest getting rid of it anyway. The Army went to the 260 amp (400 Amp total output) on the FMTV starting in 2007 due to high failure rates as well as the move to AGM batteries making the 100 amp's 400% too-small size discrepancy for the battery bank no longer being something they could ignore.

I have two of the v-belt 260 Amp upgrade kits from HUPP Aerospace. Brand new. The kits are $6k and include the LBCD (replacement for the PPD), along with the bracketry to move the shock tower, mount the alternator, and replace the PPD with the LBCD (included) along with belts and hardware and instructions. These kits were produced for the military to upgrade the older trucks and are from 2017.

I also have a working / tested late-model 100A with diagnostic LED's for $800. But I would highly recommend the 260. They are TANKS and I've never actually seen one that was legitimated "failed".