IH 3514 generator

Hello again,

Another question: my generator doesn't charge well. I ran wires to make it a motor and it barely turned. Pulled it apart and the commutator is worn down to where there are practically no slots. Is there a source for parts or generators or maybe install a newer alternator??? Any suggestions are appreciated.

If your tractor is a "worker" I'd recommend replacing the generator with a Delco 10SI (internally regulated) alternator. It'll do a better job keeping the battery charged and it will cost less than getting your old generator back into shape.

I'd stick a Delco 12SI or a Hitachi on there
and be done with the generator. Easy swap.
Delco 10SI, 12SI and Hitachi 60 amp off an 80s
Subaru have the same footprint and same wiring
with internal regulator. Delco 10SI is a
inferior to the 12SI but either can do fine for
what you want. Hardest part of the swap is
making the bracket to hold the alternator and
getting the right pulley on it to match your V-
belt. On my 3414- I used the old pulley off the
failed generator on the alternator. Fit right
on. My 3414 though has the British four-
cylinder engine. I don't know what your 3514
has.

If there is enough mica (red stuff)left between the commutator bars, carefully lower the spaces between them around a 1/32 to 1/16 of an inch with a narrowed hacksaw blade, ground to just fit the groove.
Keep them all even by counting the strokes, then polish the commentator chucked in a drill press with sand paper. Do not use emery cloth. and blow residue off with compressed air.
If the brushes have worn a groove into the commentator, a machinist can true it back up for you, then repeat the above process.
Replace the brushes with new ones of the correct grade.

Any local starter / alternator shop can re-cut these grooves for you, most have a machine designated for this purpose. Most could rebuild the generator for you.

The Delco 10SI and 12SI are very similar alternator. The difference is the 12SI was designed for higher output and so has better cooling. The rectifier bridge has a bit larger heat sink. The rear frame has more ventilation slot area. The fan is more efficient at moving air.

When replacing a generator with an alternator there really is no advantage to using a higher output unit since even the smallest alternator will put out more amps than the original generator. The biggest problem with those alternators on farm equipment is vibration. The 10SI alternator is available with swing brushes rather than the original sliding brushes which greatly increases their life and pretty much eliminates the brushes hanging up in the holder. I have seen 12SI alternators with the swing brush assembly but what they are is the rear frame, brushes, and rectifier bridge from a 10SI mated with a 12SI front frame. There is not much advantage to that unit unless you are looking at a 100 amp unit.

Back of the 10SI type 110 with sliding brushes




Back of the 10SI type 116 with the swing brush assembly. Note the additional screw and relocated slot for the brush retainer pin use for assembly. It also has additional reinforcement webs for the rear bearing.

Thanks to all of you for your replies. Makes my decision much easier. Now to find the bracket to replace the generator bracket.

Thanks again.