Skil 574 Circular Saw Disassembly

Intro: Skil 574 Circular Saw Disassembly

For most folks, the Skil 574 Circular Saw, like most hand tools, is not worth repairing.  In the case of this saw, it made a god-awful shrieking noise when operating, which seemed beyond the decibel level and audio frequency of what a Skil Saw should sound like. 
I wanted to fix this saw because (1) it is a "Made in USA" tool, (2) I'm cheap, (3) I like taking stuff apart.
This Instructable covers the disassembly and reassembly of the Skil 574 Circular Saw.

You will need
(1) Torx T-25 Tip
(2) Phillips Screwdriver #1 or #2

You might need
(1) Bearing Grease
(2) Electrical Tape

STEP 1: Freeing the Blade Guard and Base Plate

The Blade Guard

The blade guard of this saw is attached with a spring.  Detach the spring at both ends and set it aside.
Using a Torx 25 wrench, detach the rubber stop.  The blade guard should now be free to rotate.

The Base Plate

The base plate is attached with a long bolt and a wing nut.  Remove the wing nut and the bolt, and the base plate can move freely.

Swing the base plate free of the saw.  The base plate contains a stop that keeps the blade guard from rotating completely.  Once the base plate is freed, the blade guard is also freed.

STEP 2: Free and Wrap the Motor Brushes

Wrapping the Motor Brushes

The motor brushes should be freed before you remove the motor shaft.  To keep the carbon brushes from springing loose, they can be wrapped in tape so they don't get tangled.

Turn the motor over, and remove the screw that holds on the grate that covers the motor.  Put the screw aside.

Remove the acrylic pieces that hold the brushes in place, and free the brushes.

STEP 3: Removing the Front of the Saw

There are 4 screws holding the front half of the saw (the part with the blade) to the back part of the saw (the part with the motor). 

Three of these screws are easy to see, the fourth is near the center.

Removing all 7 or so screws in the front of the saw is fine -- just follow the pictures.

STEP 4: Removing and Cleaning the Motor Shaft

When the front part of the saw is removed, the motor shaft may come out with it.

STEP 5: Freeing the Drive Gears

Remove the 3 remaining screws on the front plate.

STEP 6: Cleaning the Gears (Optional)

If you (1) know what you're doing, or (2) feel adventurous, you might want to clean the gears.

I chose to do so because I have some general-purpose bearing grease left over from some automotive work.  I don't know whether it'll be okay for the saw to use this grease.

STEP 7: Removing the Motor Coils

STEP 8: Removing the Switch, Power Cord, Motor Coils

STEP 9: Cleaning the Motor Cavity

STEP 10: Reinstall the Power Switch

STEP 11: Lubricating the Motor (Optional)

I figured it wouldn't hurt to lubricate the motor while I had it disassembled.
The saw was previously shrieking like a 10 amp banshee, so I figured a bit of general purpose grease would help.  I used automotive grease.

STEP 12: Reinstalling the Motor Coils and Motor Shaft

Insert the motor coils back in the motor cavity, and adjust the tape-wrapped motor brushes until the motor coil assembly sits comfortably in the cavity.
Using the two bolts, bolt in the motor coils.  Be careful to not crush (1) the motor brushes at the back of the motor, and (2) the wires that come very close to the retaining bolts.

Take the motor drive shaft, and replace the washers at each end.
Insert the motor drive shaft, being careful not to lose the washer, nor crush the tape-wrapped motor brushes.

Go back to step 4, and you can see that I screwed up the order of the washers on the geared end -- the metal washer should be on the bottom! 

STEP 13: Install the Gear and Blade Guard

STEP 14: Reinstalling the Motor Brushes

Using a small screwdriver, you can keep the brushes inside the casing, so they don't spring out when you reposition the brush housing.
When reinstalling the acrylic pieces, do not over-tighten.

STEP 15: Reinstall the Base Plate

Reposition the base plate, and secure it with the long bolt.  The bolt fits through the base plate as shown in the assembly pictures.
Note the position of the base plate and the blade guard. There is a right and wrong orientation of these parts when you screw in the rubber stop.

Reattach the rubber stop and the spring.

STEP 16: Conclusion

Hopefully you have no parts left over.
If everything's accounted for, the saw should be ready for test. 

I found that the saw was still quite loud when I finished, but it worked.

Comments

[noladom]

Hi,
I just opened the motor grate on my Skilsaw 574 for the first time to check the brushes and clean it up a little, but when I took the brush holders out the brushes and springs popped out (rookie mistake I know) and now I don't know how the wires are supposed to attach or exactly where.Can anyone give any guidance or even provide photos as to where exactly the wires go on the brush holders/springs? (I've provided a couple pictures of what I have).The saw was working fine before and as it's my deceased father's saw I'd rather not just trash it for a new one.I have scoured youtube and online with little luck except for this thread, but the pictures here don't show the wires at a helpful angle.Any help would be greatly appreciated.Thanks.

[Nuclear_Narwhale]

Does anyone know where I can get New motor brushes?

[iamwaltmac3]

I don't know if somebody has been in this before I got it used at a flea market. My conundrum is that the blade spins in the wrong direction. I have the ability to disassemble and reassemble the item if I know how to change the direction of the blade.
It's vital signs are as follows:
Matched-Craft
Job Rated Power Tools
Model CS 88 BB
7 1/4 Circular Saw
volts 113 amps 9.0 rpm 5500
500 west huron st chicago 10, ill
It is almost identical to the unit that was disasambled in the video.

[rch kaypang]

you should replace all bearings, then it will be smooth turning. Don't use cheap bearings, get high speed bearing with C3 tolerance. Timken products must have those, it's USA company :)

[BrentG41]

Do you have a part number for the trigger switch. I have not been able to find one.

[auto13142828]

I just restored my 1982 Skil 574. Wiped out all grease which had become too thick. Replaced with wheel bearing grease. Holding back the springy electrical brushes using tiny screwdrivers was tricky. I re-filled the wool with light oil too. It took a couple hours and the saw sounds normal again. Thanks for the photos.

[PCB511]

Any tips on fixing the safety trigger? Mine popped out. I have the trigger and spring. I can't see how it stays in place (but I haven't disassembled it).

[Ragout1]

Thanks for this. It helped me reassemble my saw correctly and stopped the screeching. Also, mine is a Skilsaw Model 1697, but appears exactly the same as your 574, except for the label. You might make that claim so others with 1697s can more easily find this page. It took me quite a bit of googling.

[KyleG111]

i had the same terrible screeching problem with my 574 and all i did to fix it was remove the cover over the brushes as well as the dust guard and there was a wool pad over the rear motor bushing, i added a liberal ammount of electric motor oil to it and soaked the wool, spun it up a few times to get the oil worked in, and then reassembled. screech gone! also i noted that the plastic cover over the motor has a small hole over the wool pad that says "oil", clearly meant for periodic addition of electric motor oil.

[cyborgv1]

A little late, but I believe part of the screeching noise you hear is from the drive gears. My blade guard was loose enough to bounce off the blade. Using a press and some ratchet sockets, I pushed the drive gear out of the copper bushing. Then I pressed the copper bushing out of the black bracket. Looking at the bushing and the drive gear I noticed some definite heat marks so I polished them up with 1000 grit sand paper. I liberally greased everything up before pressing back the parts together. The directions you provided were very helpful in keeping everything in order and provided great visual aids. Mine does not sound any worse than any other skil saw I've used, and the guard while a little loose can not hit the blade.

[BDFan1981]

Scratch that: that date of manufacture would be September 1976.

[BDFan1981]

In that case, that means your saw was made in December 1976, to technically mean a 1977 sales-year product.

[BDFan1981]

John, I have some questions about your saw.

1 = what does it say on the white decal applied on the motor assembly (not the nameplate, but the smaller decal)? Example: CT3 (June 1976).

2 = Is it true that your saw was painted dark gray? I'd like to think it is, because that paint is now flaking off. Originally, this saw was all bare chrome on the motor housing. When this model switched to a plastic double-insulated (two-wire cord set) motor from Type 8 (this one is a Type 7, making it the last grounded wire unit) the motor housing was dark gray plastic.

[John_NY]

1 - the decal says CW3
2 - the saw is indeed dark gray on over metal (and gets fairly warm, since it conducts heat). I believe it is gray all over (probably also under the name plate), indicating a factory paint job.
Interesting question!

[Phil B]

I remember wanting one of these saws. My brother gave me one he was no longer using. The blade shaft had some run out, that is, it moved laterally a millimeter or so when started. Also, the base plate had a little too much flex in it and the saw wandered from a straight line while cutting. I added a thicker steel plate to the underside of the base. My daughter has it now.

I am wondering if your screeching noise came from a worn or dry bearing. Also, I would have filled the void area in step 13 (3rd photo) with grease.

Thank you for a very practical Instructable.

[Dr. Pepper]

Make sure you put it back on correctly!