Pre 1957 Panheads, Knuckleheads, 45, and K models came with a three brush
generator. 1958 and later generator models came with a two-brush generator.
There are several reasons some one may want the change from a three-brush
generator to a two-brush generator. The biggest reason is to get the upgraded technology. The three brush dose
not use a voltage regulator. It is set up to put out a set amount of amperage.
This system dose not handle switching electrical components on or off very
well. It also requires an extremely robust battery to be able to handle
the resulting periods of overcharging and under charging. These days it
is hard to find a good 6-volt battery that can handle it. This leads to
another reason. You can switch to a 12-volt system. There are those who want to keep the bike stock. This is a very noble and
worthy effort for a show bike or collector. Unfortunately it is getting
hard to find parts for the old 32E generators. If you do find parts it
is getting even harder to find someone that understands how to make it
work. Most of the craftsmen of that era have retired or past away. If you
have a collectable or show bike leave it stock. If you want to ride it
upgrading is a good choice. When putting a two-brush generator on a 1957
and earlier Harley Davidson there are some things to consider.
The two brush and three brush generators use different oil deflectors.
The oil deflector prevents too much oil from getting on the ball bearing.
On two brush models it also sets the location of the gear.
Since the gear is pined in place on the three brushes, the oil deflector
has a spring between it and the bearing to hold it up against the gear.
The oil deflector used on two brush generators has a built in collar. The
gear is drawn onto the shaft with a nut until it pinches the oil deflector
tight against the inner race of the ball bearing. This sets the location
of the gear and locks the armature in place.
When changing from a three brush to a two-brush generator do not use the
old oil deflector and spring. Use Harley Davidson part # 31035-58.
On three brush generators the gear is held on with a roll pin. These gears
have a hole for the roll pin. On a two brush generator the gear is held
on with a nut. The gears are the same except for the roll pinhole. Ether
gear can be used on the two-brush generator. The three-brush generator
needs gears with the pinhole.
Generator gears have ether 13 or 14 teeth. All models used 14 tooth gears
through 1957. 1958 to 1969 Panheads and Shovelheads used a 13-tooth gear. The gear mesh
on 1957 and earlier models is adjustable. It may be possible to use a 13-tooth
gear if the proper gear mesh can be achieved. This will increase the low
speed generator output by 66%. See shimming and strapping.
All of the 45’s, K models and Sportster use a 14-tooth gear. 45’s require
a built in slinger. The timing covers on the 45’s have a spring-loaded
brass breather that rides on the end of this special gear.
Police models came with fan-cooled generators. These generators have a
large squeal cage fan attached to the commutater end of the generator.
Fan cooled generators use a special ratchet gear. The ratchet is built
in to take excessive stress off the timing gears during over revving situations.
When replacing a fan cooled unit with a generator that is not fan cooled
use a standard gear.
It is best to reuse the original gear when ever possible. Finding a good
aftermarket gear can be difficult. The gear must be a press fit on the
shaft. A loose fitting gear will ware the shaft out.
The three-brush generator mounts with ¼ 24 bolts. The two brush generator
mounts with 5/16 24 bolts. There are two methods to mount a two-brush generator
on 1957 and earlier motors. One is to enlarge the mounting holes in the
engine case to fit the larger 5/16” bolts. The second method is to use
helicoids to reduce the 5/16-24 threads in the mounting holes down to ¼-24
and use the stock bolts. I recommend using the ¼-24 bolts then shimming
and strapping.
H Option
When ordering a Cycle Electric Inc generator add the letter H to the end
of the part # to get ¼-24 helicoids pre installed.
On 1957 and earlier motors the mesh between the generator gear and the
idler gear inside the motor needs to be set. This is accomplished by shimming
between the generator and a cradle on the engine case. The object is the
achieve .002” lash between the generator gear and the idler gear. You can
check this by taking the timing cover off or by removing the front lifter
block. Rotate the motor several times to find the tightest spot between
the gears. Change the amount of lash by install different thickness paper
shims between the generator housing and cradle on the engine case below
the generator gasket serface. Tighten the strap and snug the mounting bolts,
then check for proper lash.
On 1958 and later models the generator is doweled in place buy the snug
fit between front bearing boss on the generator and the hole in the engine
case. The gear mesh is a manufactured tolerance and is not adjustable.
Note: S&S generator motor cases are set up like the 1958 and later.
No shimming is requierd.
M Option
Since there is no cradle on 1958 and later motors, the out side dimension
on the two brush generator is not a critical dimension. When installing
a two-brush generator on a 1957 and earlier motor there may not be clearance
between the generator and cradle. If this is the case you will not be able
to achieve proper gear mesh. Sometimes the second mounting bole will not
line up. When ordering a Cycle Electric Inc models 65A (part # DGV-2569)
or DGV-5000 add the letter M to the end of the part #. With the M option
we set the outside dimensions to allow room for shimming. The Cycle Electric
Inc models 61 6 volt, (part # DGV-2578) DGV-5006 6 volt and DGV-5000L 12
volt generators are intended to go on the older motor and get the M option
automatically.
The two-brush generator uses a regulator instead of a cut out relay. You
will need to find a place to mount the regulator. Connect the “A” wire
or terminal on the regulator to the “A” terminal on the generator. Then
connect the “F” wire or terminal on the regulator to the “F” terminal on
the generator. Connect the B+ wire or terminal on the regulator to the
battery.
If you are using the Cycle Electric Inc DGV-5000 generator with built in
regulator simply connect the battery wire from the old cut out relay to
the “B” terminal on the generator. If you have a generator light connect
the wire from the light terminal on the old cut out relay to the “L” terminal
on the DGV-5000. Do not use the wire from the “S” or switch terminal on
the 32E generator. This wire comes from the ignition switch. Remove this
wire or tape it off. You can then remove the cut out relay.
Let the road you choose to ride bring you happiness.
Karl S Fahringer
President
Cycle Electric Inc