Fan Shroud Removal/Replacement

(Engine Removed from the Car)


Note: This procedure applies to the doghouse fan shroud.

Fan Shroud Removal -

  1. 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.
  2. Disconnect the two sparkplug wire holders from either side of the fan shroud.
  3. 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.
  4. 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.
  5. 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 end.

  6. Remove the tinware from around the rear (rear is rear) of the engine.
  7. 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.
  8. 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?

  9. 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).
  10. 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.
  11. Remove the oil cooler tin and the plenum that runs through the firewall from the front of the fan shroud.
  12. Disconnect the connecting link from the left side cooling flaps.
  13. 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.
  14. 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.
  15. 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 -

  1. Thoroughly clean the fan and the fan shroud, inside and out. Again, painting will make the fan shroud look very nice.
  2. Note: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.

  3. 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.
  4. Install the doghouse cover and the oil cooler vent (the vent will go through the firewall tin.
  5. 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.
  6. On the rear of the engine, reattach the thermostat connecting rod to the right-side cooling vanes.
  7. 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 shroud.

    Note: 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.)

  8. 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 shroud.
  9. Note: The fan shroud should fit tightly over the cylinder cover tin. Screw it down on both ends of the shroud.

  10. Slip the alternator strap around the alternator and alternator pedestal tighten the 13mm nut.
  11. 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 stand.
  • 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.


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