Fan Shroud Removal/Replacement
(Engine Removed from the Car)
Note: This procedure applies to the doghouse fan shroud.
* * * *
Fan Shroud Removal -
- Remove the engine from the car in accordance with the Engine
Removal Procedure. The shroud CAN be removed with the engine
in the car (see the separate procedure
for removal of the fan shroud with the engine in the car), but
the engine comes out so easily it's usually easier to remove engine
first. Working on the engine is so much easier when it's sitting
on the driveway or the workbench.
- Disconnect the two sparkplug wire holders from either side of
the fan shroud.
- Disconnect the wire to the coil from the distributor and any
other wires or hoses that might prevent you from lifting the fan
shroud straight up.
- Remove the carburetor (the automatic choke interfers with the
removal of the alternator). Stuff a clean rag into the throat
of the carburetor and into the intake manifold to prevent foreign
material from getting inside.
Note: We have used the word "alternator" in this article,
but the procedure works for older generator models, too. Not sure
if yours is an alternator or generator? Easy -- generators have
a constant diameter from one end to the other, whereas the later
alternator is "fatter" at the fan belt end than on the fan shroud
- Remove the tinware from around the rear (rear is rear) of the
- Using a long thin screwdriver in the notch in the alternator
pulley to prevent the pulley from moving, and with a 19mm box-end
wrench (ring spanner), remove the nut in the center of the pulley.
Remove the alternator pulley outer half, then remove the fan belt.
Note: Keep track of the number of spacer washers and
other bits and pieces so that the assembly can be put back together
just as it was taken apart. This is important -- you should always
have the same number of spacer washers in total, either between
the pulley halves or under the nut, otherwise the nut may not
snug down correctly, making the fan belt either too loose or too
tight. So don't lose any, okay?
- Remove the fillister head (cheese head) screws that hold the
right air duct lower piece under the thermostat (there are screws
on the crankcase, the heater box, and the cylinder cover plates).
- Unbolt the thermostat from its bracket and unscrew the thermostat
from the connecting rod. If the thermostat bracket is to be removed
from the side of the crankcase, scribe its location to simplify
adjustment of the thermostat when it is replaced.
- Remove the oil cooler tin and the plenum that runs through the
firewall from the front of the fan shroud.
- Disconnect the connecting link from the left side cooling flaps.
- Loosen the bolt in the alternator mounting strap, then slide
the strap forward (towards the front of the car) and off of the
alternator support stand.
- Remove the fillister head screw at each side of the fan shroud
(the screw on the left side also supports the metal fuel tube).
Then lift the fan shroud with the attached alternator straight
up unti it is clear of the oil cooler.
- Throroughly clean the fan and the fan shroud, inside and out.
Painting the fan shroud adds a nice touch. You can use any color
you like on those engine parts that are NOT in contact with the
hot oil, but for those parts in contact with the engine oil, black
is the best color for shedding heat.
Doghouse Fan Shroud Installation -
- Thoroughly clean the fan and the fan shroud, inside and out.
Again, painting will make the fan shroud look very nice.
can use any color you like on those engine parts that are NOT
in contact with the hot oil, but for those parts in contact with
the engine oil, black is the best color for shedding heat.
- Install the alternator fan assembly into the fan shroud. Make
sure the four bolts that hold the outer fan cover to the shroud
are securely tightened.
- Install the doghouse cover and the oil cooler vent (the vent
will go through the firewall tin.
- Before attaching the thermostat connecting rod to the cooling
vanes, slip it down between cylinders #1 and #2 and make sure
it will move up and down without binding.
- On the rear of the engine, reattach the thermostat connecting
rod to the right-side cooling vanes.
- Carefully place the doghouse fan shroud down on top of the cylinder
cover tin, making sure that -
- The thermostat connecting rod slides properly between cylinders
#1 and #2 without binding;
- The oil cooler is not damaged during installation of the fan
There are two engine tin screws on either side of the fan shroud,
down at the base, that hold the shroud in place. You may need
a flat-head screwdriver to pry open the cylinder tin slightly
to accommodate the shroud. (The shroud tin goes INSIDE of the
cylinder tin, all the way around.)
If you have removed the generator/alternator, place the two
cover plates back on and bolt them down with 10mm bolts (into
captive nuts on the other side). Use Loctite and lock washers,
as these bolts aren't something you want to lose inside the fan
The fan shroud should fit tightly over the cylinder cover tin.
Screw it down on both ends of the shroud.
Slip the alternator strap around the alternator and alternator
pedestal tighten the 13mm nut.
Spin the fan and check for rubbing. You may need to level the
fan and alternator by adding a shim between the alternator pedestal
and the alternator or loosening the hold-down strap a bit. The
result will be a smooth spinning fan that can't rub on the shroud.
During the installation of the fan shroud, observe
the following points -
- Take care to assure that the thermostat connecting rod makes
its was down between the cylinders without binding. The rod
passes through a slot in the air control plate between the right
side cylinders. Make sure that these small flat plates are in
place between the cylinders on both sides of the engine -- they
are essential for directing air through the cylinder fins for
maximum cooling efficiency.
- Replace the cooling vane connecting link AFTER the fan shroud
has been installed.
- Replace the strap that holds the alternator to the alternator
- Reinstall the fan pulley and the fan belt just as these components
were taken apart. Note the order of the various washers and especially
the number of shim washers. Make sure the small Woodruff key in
the shaft is replaced properly.
- Following installation of the fan belt, check and adjust the
fan belt tension. The belt should deflect about 10mm when depressed
with your thumb. If necessary, remove the nut from the center
of the alternator pulley and separate the pulley halves. Any spare
shims are stored between the outer pulley half and the fas pressure
washer under the nut so they are available should you need to
replace the belt in the future.