Part Location Diagram of 42-66-0785 Milwaukee Chuck (1/2-inch)
See part 2 in the diagram
Replacing your Milwaukee Cordless Drill Chuck (1/2-inch)
( Grid squares measure 1x1 inch )

Chuck (1/2-inch) 42-66-0785

Manufactured by:
Milwaukee
ERP Number:
ERP10129275
Part Number:
42-66-0785
Original Equipment Manufacturer ?
In Stock
Delivers in 3-5 Business Days!

Easy 

Less than 15 mins 

(12 rated repairs) ?

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Product Description

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This is an authentic Milwaukee part, sold individually. If your drill's bit retention is suffering, the rotation feels stiff, or the chuck has seized up entirely, a new chuck should fix the problem. The chuck is the top portion of the drill that holds the different drill bits. It is compatible with the hammer drills listed below. In order to install this chuck you will need to thread the chuck assembly onto the spindle then secure the chuck assembly as tightly as possible (by hand). Then open the chuck to accept the retaining screw and install the retaining screw. Secure the screw with a Phillips screwdriver. The screw is reverse threaded requiring counter clockwise rotation to secure.

Troubleshooting

This part works with the following brands:
  • Milwaukee
This part works with the following products:
  • Cordless Drill
  • Hammer Drill

Videos For installing this part.

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Replacing your Chuck (1/2-inch)
Replacing your Chuck (1/2-inch)
Replacing your Chuck (1/2-inch)

Customer Part Reviews

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Average Rating (out of 5):
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Customer Repair Instructions

All our customer repair instructions are solicited directly from other customers just like you who have purchased and replaced this exact part.

Easy 

Less than 15 mins 

(12 rated repairs) ?
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  • 2
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Chuck won\'t close

William from Sanford, North Carolina

2 of 2 people found this instruction helpful.
Difficulty Level:
Easy
Total Repair Time:
Less than 15 mins
Tools:
Screw drivers
Parts Used:
42-66-0785
I removed the LH chuck screw from the chuck. I was able to close the chuck tight enough on the short end of an allen wrench. I then put the chuck in drill mode and in low gear and laid it on the work bench. I then hit the allen wrench with a hammer a few times and finally the chuck was loose. I removed the the old chuck from the spindle a nd put the new chuck on as tight as I could with my hands. Then I screwed in the chuck screw and I was done.
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Chuck would only tighten half way. But was about 5 years old with lots of use.

william from deltona, Florida

1 person found this instruction helpful.
Difficulty Level:
Easy
Total Repair Time:
Less than 15 mins
Tools:
Screw drivers
Parts Used:
42-66-0785
Watch your video !!! That\'s how I learned it and about left hand thread.


https://www.youtube.com/watch?v=usC8unA5RiA

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The keyless chuck broke.

Josh from South San Francisco, California

0 of 1 people found this instruction helpful.
Difficulty Level:
Easy
Total Repair Time:
Less than 15 mins
Parts Used:
42-66-0785
1. Unscrew reverse thread Torx 27 screw in chuck
2. Unscrew chuck
3. Screw on new chuck
4. Reinstall Torx 27 screw
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Chuck locked up

justin from TAYLOR, Michigan

0 of 1 people found this instruction helpful.
Difficulty Level:
Easy
Total Repair Time:
Less than 15 mins
Tools:
Screw drivers
Parts Used:
42-66-0785
The teeth inside stopped moving . I was able to get to the inner screw easily because everything was locked open. Once out I did have to use a pipe wrench on the outer collar . Carfully losened that and the entire chuck removed from the drill. I reffered to a you tube video for this process just improvised with the pipe wrench because o f my case of damage
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Drill Chuck went bad, had to replace

Doug from Hillsboro, Illinois

0 of 1 people found this instruction helpful.
Difficulty Level:
Easy
Total Repair Time:
Less than 15 mins
Tools:
Screw drivers
Parts Used:
42-66-0785
Googled \"replacing a Milwaukee drill Chuck\". Watched a YouTube video about it. Very simple replacement. https://www.youtube.com/watch?v=x0y4mfUODsY
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Chuck wouldn\'t close

Tom from Florence, Kentucky

0 of 1 people found this instruction helpful.
Difficulty Level:
Easy
Total Repair Time:
Less than 15 mins
Tools:
Screw drivers
Parts Used:
42-66-0785, 05-88-1500
1. Watched video
2. Removed screw
3. Used allen key and hammer
4. Assembled chuck per video

https://www.youtube.com/watch?v=usC8unA5RiA
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Chuck needed replacing due to wear & tear

DEREK from Miami, Florida

0 of 1 people found this instruction helpful.
Difficulty Level:
Easy
Total Repair Time:
15 - 30 mins
Parts Used:
42-66-0785
I actually followed a youtube video on the repair, and it was very concise.
I had to use a torx drive to remove the center screw ( LH THREAD) that was securing the chuck to the drill. Once I removed it, I then used a very large allen key, tighten it onto the chuck and hit the allen key to loosen the chuck from the drill. I unscrewed the chuck, replaced it with the new one, tighten it as much as I could, then secured it again with the torx screw...
Took me all of 15 minutes
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Chuck was not holding bits.

John from Irwin, Pennsylvania

0 of 1 people found this instruction helpful.
Difficulty Level:
Easy
Total Repair Time:
Less than 15 mins
Tools:
Screw drivers, Wrench set
Parts Used:
42-66-0785
1. Removed the screw inside the chuck, it is reverse threaded so it loosens to the right.
2. Tightened a large Allen wrench in the chuck.
3. Placed the drill on a table and used a hammer to sharply it wrench several times until it loosened.
4. Revered the steps to install the new chuck.
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Chuck on 1/2 inch Milwaukee cordless drill had broken, would not hold a bit securely.

ROBERT from Sugar Land, Texas

0 of 1 people found this instruction helpful.
Difficulty Level:
Easy
Total Repair Time:
Less than 15 mins
Tools:
Screw drivers
Parts Used:
42-66-0785
Repair was easy, followed your YouTube video.

Removed the original retaining screw. Unscrewed the old chuck. Screwed on the new chuck. Installed the new retaining screw. Job done. I suggest you buy a new retaining screw when you purchase the drill chuck.
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Chuck was sticking in places

Scott from Hayden, Idaho

0 of 1 people found this instruction helpful.
Difficulty Level:
Easy
Total Repair Time:
Less than 15 mins
Tools:
Screw drivers
Parts Used:
42-66-0785
1> open chuck completely
2> removed chuck retaining screw with a # 2 Phillips
3> Placed large allen wrench in chuck and tightened the chuck.
4> held drill and struck allen wrench with rubber hammer, took 3 blows to loosen it.
5> finished removing old chuck by hand and placed new one on and hand tightened.
6> replaced retaining screw and tested, back to like new.
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Model Cross Reference

This part works with the following models:
ERP Number: ERP10129275
Manufacturer Part Number: 42-66-0785
Brand Model Number Description
Milwaukee 2602-059 Cordless Drill - Milwaukee 2602-059-(D37a) Parts
Milwaukee 2602-20 Hammer Drill - M18 1/2&#34 Compact Hammer Drill
Milwaukee 2602-22 Hammer Drill - Milwaukee 2602-22-(C15a) Parts
Milwaukee 2602-22CT Cordless Drill - Milwaukee 2602-22ct-(C15d) Parts
Milwaukee 2602-22DC Hammer Drill - M18 1/2" Compact Hammer Drill