Dewalt DW972 Cordless Drill

rick7938 · 05-18-2006, 09:49 AM

I have a Dewalt DW972 12-volt cordless drill that has served me well for the last few years. Yesterday I dropped it off of the step ladder onto a concrete floor - NOT GOOD!. When I tried to use it again, it will still run, but seems to have lost most of its torque. The motor has the smell of a burned-out electrical motor, ozone smell.

I am wondering if, perhaps, part of the armature has been shorted out by debris that was knocked loose during the fall or if the brushes may have been damaged? I don't know that it is worth sending it to a repair shop, so I thought that I would try to diagnose and repair the problem myself.

Anyone have any suggestions?

Thanks in advance.

Monty · 05-18-2006, 10:01 AM

Yikes! No idea what the problem is, but it don't sound good...

I hope you can get it fixed. If not, then the best remedy to help with the grieving process is to go buy a newer, even better one!!!

(BTW, I'm gonna move this into the "power tools" forum... while it technically does not have a "tail", it does still burn electrons! We can't have any noise makers here in the HT forum!!!

)

NCPete · 05-18-2006, 10:12 AM

I have an older 12 volt DW that I am considering rebuilding the battery on, and replacing the brushes. everything else in my shop is 18 V, so it is not like I can swap batteries back and forth, it is the learning experience I am going for. Perhaps a first step before considering tackling something like Steve D's big project??

SteveColes · 05-18-2006, 12:00 PM

Originally Posted by rick7938

I have a Dewalt DW972 12-volt cordless drill that has served me well for the last few years. Yesterday I dropped it off of the step ladder onto a concrete floor - NOT GOOD!. When I tried to use it again, it will still run, but seems to have lost most of its torque. The motor has the smell of a burned-out electrical motor, ozone smell.

I am wondering if, perhaps, part of the armature has been shorted out by debris that was knocked loose during the fall or if the brushes may have been damaged? I don't know that it is worth sending it to a repair shop, so I thought that I would try to diagnose and repair the problem myself.

Anyone have any suggestions?

Thanks in advance.

Yeah, you are just going to have to open it up and see what's going on. Sometimes, it becomes obvious and sometimes it isn't. If DeWalt has an exploded parts diagram available, please get it before you do anything.

Steve D · 05-18-2006, 02:02 PM

I wish you luck with the repair but it doesn't sound good. Unfortunately, even the good cordless tools have become more of a disposable item. My DeWalt got to the point that the batteries would no longer hold a charge and it was about the same price to buya new drill as it cost to buy the batteries. You may get lucky and have it be something small but know your options for something new before you drop a lot of money on parts.

rick7938 · 05-18-2006, 02:22 PM

Well, I think that I fixed the cordless drill. Seeing that I had nothing to lose, I took it apart and gave the whole mess, motor and all, a bath in a coffee can full of kerosene. You should have seen all of the gunk that came out of it. Then I got the bright idea to take it apart, blow out the kerosene, and lube all of the gears. DON'T TRY THIS AT HOME!

There are at least 300 little gears and stuff that fall out of the drill when you take it apart. Seriously, I do have the parts diagram and was able to lubricate all of the gears with some moly grease, get it back together, and drive 2" drywall screws through two 2X4's splitting them in the process, so it definitely has its torque back. Plus, it operates more smoothly than I can remember.

So, luck was with me this time. If you do decide to try this at home, be sure that all minor children are safely out of ear shot, and your 3-lb sledge is locked up in your gun safe.

Thanks for the responses.

Monty · 05-18-2006, 02:24 PM

Wow!!! I'm impressed! Now we know what you've been up to all morning!!!

I'm glad you got it working again.

Steve D · 05-18-2006, 02:38 PM

It's probably in better condition than new at this point! Great work

DaveO · 05-18-2006, 02:43 PM

Any spare parts

I always have spare parts when I take something apart and put it back together

I'm glad that it worked out well for you, I bet you feel good by fixing it yourself

Dave

sapwood · 05-18-2006, 02:46 PM

Great recovery Rick

I'm heading out to the shop now to start throwing tools around so I can improve them

Sapwood

Canuck · 05-18-2006, 04:13 PM

Congrats Rick!

(In some ways I would have been a little disappointed that I lost another excuse for new one!

)

Now you have yet another profession that you can fall back on!!!

Great work!

Wayne

McRabbet · 05-18-2006, 05:18 PM

Originally Posted by DaveO

Any spare parts I always have spare parts when I take something apart and put it back together
Dave

Spare parts? I never have any, because they all fall off my bench only to roll somewhere unknown under my lumber rack or a tool or some loose shavings under my drill press -- that way, they aren't "spare" anymore; they're "scarce" parts.

Rob

toolferone · 05-18-2006, 06:13 PM

Well I was going to offer some help, but it seems you dove right in

. I worked for Dewalt for almost 2 years in their repair department. I know that drill very well. Glad you got it fixed.

rick7938 · 05-18-2006, 08:49 PM

Thanks for the offer of help. I may be asking for your help. Just because my handywork works today doesn't mean it will work tomorrow. It still has that ozone smell, plus I am afraid that the kerosene that I used to clean the crud out of the drill may have compromised the lubricant in the bearings of the motor, if there is any.

I will advise you if it goes belly-up.

Many thanks to all.

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