Ryobi HD420 Quick setup guide

RYOBI
1/2 in. HAMMER DRILL
DOUBLE INSULATED
MODEL NO. HD420 / HD4201
REPAIR SHEET

2
RYOBI 1/2 in. HAMMER DRILL – MODEL NUMBER HD420 / HD4201
2
1
3
4
5
6
11
9
8
7
10
5
16
17
18
19
20 21
22
14
1
14
15
24
23
6
12
13
WARNING: Improper repair of a double insulated tool can result in damage to the double insulation system possibly causing electrical shock or
electrocution. Any repairs requiring disassembly of your tool requires safety testing and should only be performed by a Ryobi Authorized Service
Center. For the service center nearest you call 1-800-525-2579.

3
RYOBI 1/2 in. HAMMER DRILL – MODEL NUMBER HD420 / HD4201
The model number will be found on a label attached to the motor housing. Always mention the model number in all correspondence regarding your
HAMMER DRILL or when ordering parts.
PARTS LIST
KEY PART
NO. NUMBER DESCRIPTION QTY
KEY PART
NO. NUMBER DESCRIPTION QTY
1 039803001007 Housing Assembly (HD420)
(Inc. Key Nos. 2 and 15)....................................1
039803005002 Housing Assembly (HD4201)
(Inc. Key Nos. 2 and 15)....................................1
2 039803001009 Logo Label........................................................1
3 039803001018 Mode Shift Button.............................................1
4 039740003029 Impact Plate......................................................1
5 039803001020 Brush Assembly................................................1
6 039740003024 Screw (M2.9 x 16 mm, Pan Hd.).......................4
7 039740003019 Bearing Cover...................................................1
8 039140001048 Ball Bearing (607-2Z) ........................................1
9 039740003015 Ball Bearing (608-2RZ)......................................1
10 039803001004 Motor Assembly
(Inc. Key Nos. 7-9) ............................................1
11 039740003001 Output Spindle Shaft
and Gear Assembly ..........................................1
12 039171001006 1/2 in. Chuck.....................................................1
13 039140001012 Chuck Screw (M6 x 25 mm,
Special, Left Hand Threads) .............................1
14 039803001016 Screw (4.2 x 16 mm, Torx Hd.) .........................9
15 039803001011 Data Label (HD420)...........................................1
039803005001 Data Label (HD4201).........................................1
16 039803001033 Switch Assembly ..............................................1
17 039140001067 Cord Clamp ......................................................1
18 039140001066 Screw (M4.2 x 14 mm, Pan Hd.).......................2
19 039140001070 Bend Relief .......................................................1
20 039803001013 Power Cord.......................................................1
21 039171001014 Chuck Key ........................................................1
22 039171001015 Chuck Key Holder.............................................1
23 039803001034 Auxiliary Handle Assembly ...............................1
24 039171001002 Depth Stop Rod................................................1
NOT SHOWN:
990000163 Operator’s Manual
8-30-16
(Rev:03)

4
RYOBI 1/2 in. HAMMER DRILL – MODEL NUMBER HD420 / HD4201
WIRING DIAGRAM
WHITE
WHITE
WHITE
BLACK
BLACK
BLACK
MOTOR
SWITCH
BRUSH
ASSEMBLY
BRUSH
ASSEMBLY
POWER
CORD