How to remove blade from a 20 inch lasco fan - Lasko 3720 Floor / Box Fan

https://www.lasko.com/products/20-inch-box-fan-b20201/

https://store.laskoproducts.com/p-1005-20-box-fan-model-b20201.aspx

bearing gone or rotor blade scraping against outer cover

Be sure the fan blades spin freely. If not,it will have to come apart.
If they do,the switch is probably bad.
Parts like this are not easy to find or replace.
Need to think about a replacement.

The 20 inch band saw uses a 150 inch blade and I'm envious. The 20 inches refers to the wheel diameter
For more information:
http://www.redmond-machinery.com/Jet%20JWBS-20.htm
I'd gladly trade.

You can blow the whole fan clean with compressed air or a compressor. It does not require removing the cover. The cover comes off with a twist and a pull, but does not stay on well afterwards, so I don't recommend removal. Farmerbear at FixYa.com

Hi, 5.2L Engines

1. Disconnect the negative battery cable.
2. The viscous fan drive and blade assembly is threaded into the water pump hub shaft. Remove the fan drive and blade assembly from the water pump by turning the mounting nut counterclockwise as viewed from the front while securing the water pump pulley. Do not remove or unbolt the fan drive and blade at this time.

Fig. : Fan blade and viscous drive (click for zoom)


The threads on the viscous fan drive are right hand threaded.

1. Remove the 2 fan shroud-to-upper crossmember nuts.
2. Remove the fan drive, blade and shroud as an assembly.

WARNING Do not place the viscous fan drive in a horizontal position. If stored horizontally, silicone fluid in the viscous fan drive could drain into its bearing assembly and the assembly would have to be replaced.
CAUTION Do not remove the water pump pulley-to-water pump bolts. The pulley is under spring tension.

1. Remove the 4 bolts securing the fan blade assembly to the viscous fan drive.
   

To install:

1. Install the fan blade on the viscous drive. Install the bolts and tighten them to 17 ft. lbs. (23 Nm).
2. Position the fan shroud, viscous fan and blade into the engine compartment as an assembly.
3. Position the fan shroud to the radiator. Insert the lower slots of the shroud into the crossmember. Install the upper attaching nuts.

Ensure the upper and lower portions of the fan shroud are firmly connected. All air must flow through the radiator.

1. Install the fan drive and blade assembly to the water pump shaft and tighten the nut.
   

Ensure there is at least 1 inch (25mm) between the tips of the fan blades and shroud.

1. Connect the negative battery cable.

Take care

In the manual in the link see page 5 for the gasket assembly.


http://www.homedepot.com/catalog/pdfimages/c2/c2a21924-5bb0-4dee-9d21-7fef537d9368.pdf

Stick a small weight to the end of one of the fan blades with some sellotape , run the fan , if the noise gets worse transfer the weight to another blade.
When the fan is running quietly go to the blade opposite to the one with the weight on and drill out a 10mm hole in the material.

Take the weight off and check for balance if it is still out drill another smaller hole in the blade till you get a balance

Drill the holes a the tip of the blade so that you get the best effect from the removal of material

This will save you buying a new blade

Try pulling on the blase with a sharp ****.

Joey Temal is right. After removing any small metal retaining clips (which are obvious and easily removed), you have to pull down ridiculously hard to get the fan blade off. Alternate short jerky pulls with steady downward traction.