AF
Low
Speed
Worm
Gear
Modification
A
simple
Modification
to
Lionel's
AF
Power
Trucks
to
increase
Gear
Ratio.
Here
is
a
simple
modification
to
the
worm
shaft
assembly
in
Lionel's
American
Flyer
power
trucks
for
improved
low
speed
and
switching
duties.
It
increases
the
Gear
ratio
from
10:1
to
20:1
using
a
drop
in
modification.
American
Models
uses
this
same
principal
by
offering
a
optional
set
of
low
speed
gears
for
their
line
of
engines.
It
so
happens
that
the
AM
gears
can
also
be
used
to
for
the
same
purpose
to
create
a
set
of
low
speed
gears
that
will
work
in
American
Flyer
Power
trucks
too.
The
difference
between
the
low
and
high
speed
worms
is
that
the
low
speed
has
a
single
start
helix
and
the
stock
worm
is
a
double
start
helix.
The
diameter
and
pitch
are
the
same.
The
shaft
that
comes
with
the
AM
gear
is
pressed
out
of
the
worm
and
the
hole
reamed
to
.124".
Pull
the
worms
off
of
the
AF
shaft
and
press
on
the
AM
worms
and
that's
it.
The American Models Part is " Low speed worm gear on shaft" Part number "GBWSLS" and costs $4.00 Each. You will need two for each power truck. I would recommend this modification to any engine that you will be using for yard duty. I have it installed in EP-5's and Geep's and Baldwin's. The only down side of the is that there is a bit more gear noise at high speed. With this mod, you can ease the slack out of a train and never spill a drop of the Conductor's coffee in the caboose. |