Chop Saw Repair – Replacing the Armature Bearing (DeWALT Part # 605040-27)
Chop Saw Repair – Replacing the Armature Bearing (DeWALT Part # 605040-27)


Is your saw making a loud squealing sound? Is it vibrating badly? If so, you might need to take a look at the armature bearings. The armature is the central part of the saw’s motor. There is a bearing mounted on either end, which allows it to rotate. Over time, these bearings will wear and will need to be replaced. When you start to notice the warning signs of a bearing going bad A squealing sound, often accompanied with a vibration. It is important to stop using the tool, and fix the bad bearing. If you continue to use the tool, the bearing will eventually seize, which will lead to much more damage. Such as melted housings or damage to the armature shaft. Replacing the armature bearing is a repair that you can do yourself. And I’m going to show you how. Hi, I’m Mark Sodja. Do-it-yourself repairs like these are easier than you might think. From lawn machines to cordless drills. Kitchen mixers. Outdoor grills. Our how-to videos walk you through each repair from start to finish. So doing it yourself means never having to do it alone. Let’s get started. I’ll begin by removing the motor end cover. It’s held in place with a couple of screws. Next, I’ll remove the brush caps and the brushes. Next I’ll remove the top half of the handle cover. To be able to remove the motor housing and the field I’ll need some slack in the wires that go between the switch and the field. To get that slack, I’ll remove the switch. And now I’ll have enough wire that I’ll be able to pull this free. The motor assembly is held to the rest of the saw with four screws. I’ll go ahead and remove those screws now and pull the motor away from the saw. There’s a rubber cup around the rear armature bearing, and at this point, the friction from that cup is the only thing holding the armature inside the rest of the motor. So, I’ll use a screwdriver and push on the rear of the armature through the back of the housing to push the armature out. Removing the fan-side armature bearing can be a little tricky. Because the gap between the fan and the bearing is very small. It’s not really practical to use a bearing puller, because most pullers won’t fit in that small space. I found the best way to do it, is to use a bearing separator. You’ll need one that’s flush on the back, so it’ll fit in that small gap between the bearing and the fan. I’ll place the separator over the bearing. And tighten it up. The next challenge is, I have very little space between the separator and the fan. So I need to support the bearing separator on the jaws of my vise. On just a very small contact point. Again, I want to be careful not to damage the fan as I mount it into the vise. That’s about as tight as I can close the vise jaws. Now I’ll use a rubber mallet to strike the end of the armature and tap the armature away from the bearing. I’ll have to stop once or twice during this process to tighten up the bearing separator. Now I’ll install the new armature bearing. I’ll place the bearing over the end of the armature shaft. And I’ll use a socket that has a diameter about the same size as the inner race on the bearing. It also needs to have a large enough inner diameter that it will fit over the armature shaft. Now the best way to seat the bearing would be to use a bearing press. But most people don’t have one of those. So again, I’ll just use my rubber mallet and carefully tap the bearing onto the shaft until it seats against the retaining ring. Now we can put the motor back together. I find it’s easiest to install the armature back onto the saw first And then slide the motor cover and field over the armature. And then get the gears to engage. And press the bearing into the housing. Like that. Now I can slide the motor housing and the field over the armature. Before I do, I want to make sure that this rubber boot is still on the rear bearing And not down in the housing. If it’s stuck in the housing, remove it, and put it back onto the bearing. So I’ll just slide this together, pulling the slack back out of the wires, as I slide it onto the armature. And then I want to make sure that the boot presses in to the housing. Now I’ll secure the motor housing to the rest of the saw with the four screws. I like to start the screws with a screwdriver To make sure that they line up and don’t strip And then I’ll finish them up with an impact driver. Now I can reinstall the switch and route the wires. I’ll start with these wires up near the switch. Get them down into the holders. Now I can secure the switch. You’ll notice that there’s two holes. For this internal screw, you’ll want to use the hole closest to the switch body. The other hole is used by a screw that comes through the handle. And now I’ll just tuck away the rest of the wires. Now I’ll reinstall the handle cover and secure it with the screws. Now I’ll reinstall the motor brushes and the brush caps. And I’ll finish up by reinstalling the motor end cover and securing it with the screws. Be sure to check back often for new videos and expert advice. If you found this video helpful, give us a thumbs-up. And leave a comment.

11 thoughts on “Chop Saw Repair – Replacing the Armature Bearing (DeWALT Part # 605040-27)”

  1. Yovany Klever Andrade Aguirre says:

    camo curar pollos

  2. Randall Clark says:

    Which model and type?

  3. Czech k9 says:

    Do you have any video how to replace a bearing for Dewalt wet saw?

  4. ben riv says:

    Do the gears take any grease??

  5. adiboy mack says:

    Please can you do a video of a dewalt wet saw please please

  6. Renee Wojciechowski says:

    I just wasted more than a minute of my life watching a stupid intro.

  7. KAREN BAKER says:

    Can u do a video of how to remove motor from housing of a B Q performance chop saw please

  8. Gil dong Hong says:

    What type of grease do you use at lubricating gear?

  9. celestin nunes says:

    Bosch 3912 12" miter saw took all screws out and still motor housing is still stuck can't separate to check armature or bearing what do I do?

  10. I do my own stunts says:

    Thanks great demo

  11. David DiRanna says:

    Of the three how video I watched replacing amature bearings this one the VERY best. Thanks

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