Replacing a Neutral Switch
neutralswitch.htm-25
There are actually TWO neutral switches. One is the switch at the clutch lever on the left handlebar. That is NOT the switch under discussion HERE. This switch under discussion here is the switch on the transmission.
Don't do a neutral switch replacement unless you are SURE
it is transmission oil that is leaking from it, or that the switch has electrically
failed. You can short across the switch wires (or ground the 4 speed wire)
to determine if the switch
has failed or not. This is a bit difficult to do without long forceps or
similar to remove the wires on the 5 speed....but the 5 speed models have a two-conductor cable
along the subframe, and you can short the cable connections to ground, one lights the oil lamp,
one the neutral lamp.
If you have an early model airhead;...a 4-speed, the switch hardly ever
fails, hardly ever leaks...and it is on the rear transmission cover, and can
be fixed, a fun chore.
On the 5 speed gearboxes, the neutral switch is on the bottom. There are
TWO versions of these switches, so be sure you get the
right one for your year bike. The switch function was reversed in the 1976
model year, and they look almost the same (unless you had them side by side).
If you have the shift kit installed, you use the late type switch.
If you have pulled the transmission rearwards to, perhaps, grease the input splines, it then may be a bit easier to remove and replace the neutral switch on the 5 speed transmission. If the swing arm is pulled to the rear somewhat, you have more room. This varies with the models over the years.
If the transmission is out an on the workbench, the job is very easy. Most folks with an electrically bad, or oil leaking neutral switch, will do as follows:
With the transmission installed on the motor, the long aluminum spacer
underneath is in the way. There is a
long steel engine mount stud that passes through it and the frame. There is a washer and nut at both ends.
You need to FIRST remove that stud and remove the long aluminum spacer, then replacing the switch is
relatively easy. The first question that comes up is how to remove that long stud,
SOMEtimes it is pretty tight in its holes, etc. The front mount should be
tight enough to hold the motor from moving if the rear stud is removed, but you
may want to support the motor, a piece of wood under the pan works nicely.
The following is ONE way, called a draw-bar method, of removing the stud
if it is quite stiff in the frame and spacer quite stiff (usually is), etc.
This method is sometime used to draw
out the piston pins...and a modified method is used at other places, such as pulling
off the head and cylinder, when they, rarely, don't come off easily. ANOTHER method
is to use a rod and a dead-blow hammer (for the stud!).
For those wanting to learn about drawbars:
1. Remove the nut and washer from one end of the engine stud...let us say the right side.
2. Tighten up the other nut....in this case the left side nut... until you just
about reach the ends of the threads. Almost always the stud will not
rotate as you tighten towards the ends of the threads. If the stud
rotates, it likely will come out easy, or at least in part easily.
3. Remove the left side nut and put just about any metal spacer you have lying around over the stud, leaving enough room to enable at
least 4 threads to be engaged by the nut. You can start with some large washers, then graduate to any old socket that
fits, with a washer if needed; or...piece of pipe ...whatever.
4. Again tighten the nut to near the end of the threads. Repeat with spacers, washers,
sockets, whatever.
Notice that each time you do this, the stud will be DRAWN OUT more to the left.
Continue and 'draw' out that stud! Clean the stud carefully....you
want it SMOOTH when you reinstall it later on.....
5. Now that you have that stud out, the next thing is to remove that long aluminum spacer. It is almost always wedged in
TIGHT! You will have to do some prying, and maybe light hammering....be careful,
do NOT bang on anything you shouldn't! Usually one simply pries a TINY bit at one end, then the other end,
back and forth, working
the spacer out slowly. I like to leave no marks, and certainly not break or crack
anything. I may use a piece of wood, or whatever is handy, to avoid
pressing on the wrong areas. A proper shaped pry bar will also work nicely.
HINT!!:
Some have asked if it is possible to spread
the FRAME a very tiny amount, using some sort of home-made tool. YES! I
have done this with one of those types of tools used to tighten a car engine
drive belt....it fit between two pulleys...improvising a modification to that
tool. I loosen the front engine mount a couple of turns
first, so a support under the oil pan is a must. It may be possible to wedge a piece of wood between the frame
members a bit. Just do NOT do more than
a FEW thousandths on an inch, so the frame will spring back. SOMEtimes just
loosening the front motor mount will enable the spacer to loosen up some!
6. With the spacer removed you now have access to remove and install the new and
PROPER part number switch and
don't forget to install the washer. DO NOT overtighten that neutral
switch! After you replace the
switch/washer, and before you install the aluminum spacer, DO NOT FORGET TO INSTALL THE WIRES!
If they do
not fit tightly onto the male spades, squeeze, SLIGHTLY, the females.
It is a VERY good idea to test things electrically...be sure the switch is
working, and you have the neutral lamp ON in neutral....and not OFF in neutral!
(that means you have the lamp ON in all 5 speeds....and you installed the WRONG
switch!). The neutral switch in all cases closes its circuit
to turn the light on.
NOTE!!....when an early transmission is converted to use the 'shift kit', the late type of switch is
required!!!
7. Now it is time to install that long aluminum spacer:
Here are the tricks to ensure success:
Read this through ahead of time, and
then you will be ready when the time comes.
1. CLEAN the spacer, inside and outside. Put a SLIGHT radius, 16th or 32nd. on the sharp end edges. This does NOT mean a 1/4" radius! What you
want to do is smoooooth the edge at both ends, so it installs easier, yet not
much end surface area will be removed from contacting. A piece of sandpaper or a mill
file works nicely.
2. FREEZE that spacer. That causes it to SHRINK in length. In
shops, we might quick freeze it with an old CO2 fire extinguisher.
3. Check the transmission area, and if any sharp edges, also remove those,
carefully. You want that spacer to install
fairly easily, but certainly not loosely!
4. Grease the stud very lightly over its full length; then install one
washer and one nut on one end, leaving the nut a bit outward, so NO threads are
exposed outboard of the nut. If you want to, spray some oil into the INside of the
frozen spacer.
5. Install the well-frozen aluminum
spacer, FAIRLY QUICKLY, and
EVENLY, don't cant it (install it as squarely as you can) using a plastic mallet or brass hammer, etc. Try to line up the holes as closely as
you can, using the #1 eyeball and the stud, a wee bit one side, other side, AND,
without waiting more than a minute more, install the stud
fully,
using a brass or plastic hammer,
gently, on the nut end. If you had the aluminum spacer
well-eyeball-centered, still frozen, and the stud greased, this will go relatively smoothly.
In some cases I have loosened the front engine mount slightly...but only if the
engine was supported at the pan; you may already have that loosened anyway.
6. Even up the stud, side to side, and install nuts and washers and
torque the nuts tightly, keeping the amount of
threads proud of the nuts roughly the same on both sides.
Revisions:
04-17-2003: add .htm title; clarify details
07-07-2003: expand and clarify procedure
08-24-2004: add techindex I.D. number; clarify some details
02-24-2005: clarifications, and again in April 2007