Milwaukee Drill Resto

[DavidB]

I picked up an old Milwaukee model 0101 drill the other weekend for $10. It worked but was louder than I think it should be. I figured this drill is from the 60s or 70s and the bearings are shot. I thought I'd replace the bearings and clean it up at the same time. This drill should have a 1/4" chuck on it but someone replaced it with a 3/8"

Here's how the drill looked when I got it.


I started by chucking up a allen wrench and using it to spin the chuck counter clockwise to remove it.


There are four screws that hold the gear case on. Removing them allows the gear case to be taken off.


Removing the gear case reveals the two screws that hold on the diaphragm. After they are taken out, I used a couple pry bars to gently remove the diaphragm.


To remove the armature, I need to remove the two plastic handle halves that are held on with screws.


Back in the vise, I used my pry bars to gently press the armature out. It'll fall out so make plans to catch it.



I lack a blind hole bearing puller and instead used the hydraulic method to drive the rear armature bearing out. If you've ever done a clutch job this method may be familiar to you.


All of my bearing pullers were too large so I had to use some Morse Taper wedges. They worked pretty well.

I used the wedges again on both of the bearings on the spindle. I finally got the bearing pulled up enough slip my puller under it.


I used a combination of paint stripper, an ultrasonic cleaner, and elbow grease to remove the flecks of paint and clean up the plastic handles. Out of the four bearings, two were toast, one was good, and one was questionable. They'll all get replaced. The power cord is also falling apart and will be replaced. I'm going to try to lightly buff the aluminum case. I don't want it to be a mirror but would like to lighten it up some. Here's how it sits currently.

 

[scaron]

nice!! great disassembly sequence, interesting to read. thanks for posting this.

 

[justanengineer]

Looks great so far! Ive got one of those drills, like everything else Milwaukee it lasts forever and is easily rebuilt for cheap. This winter hopefully I will get back to restoring my completely aluminum bodied 1968 Sawzall, you just gave me a ton of motivation. Thanks!

 

[ADSR]

sub'd

 

[sasquatch12]

Nice work, great pics.

 

[BFHtime]

As a kid I would attempt to fix my dad's old tools he was about to discard. I would keep them for parts and would often be able to repair worn out, and sometimes broken tools. In my teenage years I had many successes.

It came in handy when I drove into a table saw while backing up. I was able to rebuild the table saw and did so with better tolerances than stock. By doing this I learned to tune tools so to speak. I find that even new tools need a little calibration at times.

By the way that table saw was pretty new at the time. It was a combination of different colors, with the newer motor, when I repaired it. It was used until the bearings wore out and the blade would wobble. Had I known how to replace the bearings, I might have tried to do replace the bearings as well.

Thank you for showing how to do the bearing replacement.

 

[1982fxr]

I can't wait to see this done...

 

[DavidB]

I called up Accurate Bearings this morning and placed an order. I think they'll get here this week and I hope to have it back together by this weekend.

 

[gilbo]

very impressive, nicely done so far

 

[ol'Red]

That is awesome.

 

[4xdog]

Try Superclean -- the purple stuff -- on the plastic handles. It does a *really* good job on tough-to-clean plastics.

Looking forward to the finished drill.

 

[gtermini]

Try Superclean -- the purple stuff -- on the plastic handles. It does a *really* good job on tough-to-clean plastics.

Looking forward to the finished drill.

But do NOT put it on aluminium. It is Lye based, and you will have a bad time.

Greyson

 

[4xdog]

But do NOT put it on aluminium. It is Lye based, and you will have a bad time.

Greyson

Yeah, it's strong stuff. It will damage some painted finishes, too, so always worth checking first.

 

[DavidB]

The postman brought my bearings today. Now that I have them its time to put my Milwaukee drill back together. I pulled the bearings out and compared them to the old ones. Sure, they should be the same but it's good to check.



I picked up a small commutator stone from McMaster and used it to clean the commutator. I got most of the carbon off but didn't make it spotless.



I started reinstalling bearings by putting the rear armature bearing back in. I triple checked that this was the correct bearing before installing it. The bearing on the front of the armature is the same outer diameter but has a different bore size. It'd be easy to put the wrong one in. I put the bearing in place and then tapped it home with a wooden dowel and hammer until it seated.



Next, I pressed the front armature bearing on.



I used my arbor press to press the armature into the rear bearing. I pressed it in until the brush sat in the previous spot on the commutator.



I cut the old cord off because it was dried out and cracked. I checked around online and found a few sites when supposedly had replacement cords. They wanted $25 so I decided to use a regular cord from a local store. The problem with using a normal cord is that it lacks the thick molded rubber piece that functions as a strain relief. The strain relief keeps the wires from being ripped out of the drill when it is tugged on. I decided to get a rubber cork and try fabbing one up myself. I eventually found the right size hole and was able to tug the cord through the cork. It didn't go in easily and I don't think it'll pull out with serious effort. I put a zip tie on the cord above the cork to some additional holding power. The zip tie had to be cut off later though because it didn't fit in the plastic handle.



I soldered the new cord to the old wires in the drill and used my multimeter to make sure that every everything was wired up correctly. I checked for continuity between the cord's prongs and the brush pockets with the drill's switch in the on and off positions. Everything checked well.



It turned out that the hardest part of the rebuild was getting the wires stuffed back into the plastic handle halves. The solder joints are stiff and the wires are probably a little longer than before. All this added up to wires that didn't want to fit where they're supposed to. My rubber cork also needed a little trimming with a razor blade. It was larger than hole in the case even when compressed. After a little adjustment it fit tightly.



Now it's time to reinstall the diaphragm. This was pretty easy even though the front armature bearing is pressed into it. You can use four screws to draw it into place by incrementally tightening them. While I still had screws in I pugged the drill up and ran it. It's much quieter now and ran smoothly. Note that the bottom two screws in the diaphragm have to be removed to install the gear case.



I put the bearings on to the spindle making sure to reinstall the shim between the gear and rear bearing. For some reason the new rear (left in the pic) bearing's bore was slightly larger than the old one even though they're the same number. I used some green Locktite to fill the gap between the bearing and spindle. I've done this on previous machine rebuilds with no ill effects.



Before putting the spindle back in its time to put the grease back in. I used some Mobil synthetic rear end grease. I wasn't exactly sure how much to put in but tried to put in as much as there was before. I doubt an exact amount is critical.



After that the chuck is put back on and I'm finished! Well, not totally. I put a little paint in the recessed logo on the sides of the case.



It drills holes pretty well as you'd expect. It does slow down some with a larger bit because its not a large drill. The drill seems quieter than before when holding it in midair and running it. With the spindle reinstalled the gears make the drill louder than when I ran it without the spindle installed which is expected. There's still the occasional rattle that I assume comes from it being a metal case. When drilling though it was louder than I thought it should be. The noise sounded like it was coming from the front near the gear. I took the gear case off again because I remembered there being a little rubber plug in the diaphragm that looked like it could press against the rear spindle gear (you can see it the the 5th pic above from here). The plug is made out of rubber and had flattened on one side. I spun it around and reassembled the drill. When I tried drilling again it seems this had quited the drill down some. I took the case back off and added a little more grease but it didn't seem to make much difference. One thing that I wasn't expecting is that after using the drill for a little bit it gets pretty warm. It's not painfully hot but you notice it. I guess that's another side effect from the aluminum case. Also, I think I'll keep an eye out for a replacement 3/8" chuck. The current one doesn't grab the bit well and allows it to slip some. The holes were the chuck key goes are also worn pretty heavily.



I'm happy with how the drill turned out and will be putting it to use in the future!

 

[ADSR]

Well done, David!!! She looks very nice!

 

[Amitygravel]

Great write up David !
Really like the rubber cork idea for the cord. Couple of my tools will get that upgrade.

 

[scaron]

great job! really enjoyed this.

 

[platform389]

A lot of work went into that, and even more preparing the photos and writeup for this thread.

Thanks for it all! Very interesting reading.

 

[Davefr]

I love these tool restoration threads!!

That drill will be good for several more decades. Those old Milwaukees were built like brick shithouses!!

 

[rick carpenter]

Great thread David, and very nice outcome! I like that you didn't polish away the vintage look and feel of the aluminum case. You may want to think about using something to 'finish' the plastic handles, maybe an automotive product that will 'feed' the plastic. One of the websites for restoring bit brace or eggbeater drills might give you some good info on rehabbing the chuck. It's worth doing if you can take yours apart, I did two bit brace chucks and one eggbeater chuck, and they work fine (and don't have an NOS look).

If you don't mind, about what did you spend on this?

 

[DavidB]

Thanks for the compliments! I'm glad everyone enjoyed the write up and pics.

If you don't mind, about what did you spend on this?

Probably too much... I've got about $45 in it total currently. The bearings on the armature were pretty pricey. Probably will put a little more into it get a chuck. Oh well, I like old stuff!

 

[Jolomite]

David, Wow! This post is inspiring for an amateur do-it-yourself-er. I am contemplating a very similar project- restoring an old Skil aluminum body variable speed drill. I've heard good things about Accurate Bearing. Do you know if they carry any US made radial bearings like the one's that you used? (Were yours marked made in the US?) I know I'm looking for a needle in a haystack and 'country of origin' can be a contentious detail, but I'd just like to do my best to find that option if it's possible. Thank you and thanks to anyone else who can share advise.

 

[zcbauer89]

Job very well done! Great walk through and rebuild!!!

 

[bonneyman]

Great write-up, snappy looking drill!