Makita GA7020 Manual

Model No.
Description
PRODUCT
CONCEPT AND MAIN APPLICATIONS
P 1 / 6
Specification
Standard equipment
Optional accessories
Dimensions: mm (")
Width (W)
Height (H)
Length (L)
Model No.
GA7020
GA7020S
GA7021
GA9020
GA9020S
473 (18-5/8)
200 (7-7/8) 249 (9-3/4)
140 (5-1/2)
Note: The standard equipment for the tool shown above may differ by country.
GA7020/ GA7020S, GA7021, GA9020/ GA9020S
Angle Grinders 180mm (7')/ 230mm (9')
The above products have been developed as the successor
models to the current 9067/ 9069 series models, featuring
durability higher than the predecessors.
Also the following optional accessories will provide
more comfort and control;
*Vibration absorbing side grip for comfortable work
*Toolless wheel cover for quick adjustment
*Dust cover attachment
GA7020S and GA9020S feature soft start.
GA7021 is designed on GA7020 for low-speed and high-torque.
Soft start feature
AC/DC switch
Double insulation
Net weight: kg (lbs)
Power supply cord: m (ft)
No load speed: min-1=rpm.
Wheel size: mm (") Diameter
Model No. GA7020 GA7020S GA9020 GA9020S
Hole diameter
b) 6,6008,500
Yes
c) Yes
Yes
No
GA7021
No YesNo
180 (7)
22.23 (7/8)
230 (9)
Australia, New Zealand: 2.0 (6.6), Other countries: 2.5 (8.2)
4.7 (10.4)
a) Differs by country.
b) 6,000 for USA, Guam, Panama
c) Exclusively for North American countries
Lock nut wrench 35 ......... 1 pc
Side grip 36 ...................... 1 pc
Vibration absorbing side grip
Toolless quick adjustable wheel cover
Dust cover attachment
L
HW
TECHNICAL INFORMATION
Continuous Rating (W)
Voltage (V) Cycle (Hz) Input Output Max. Output (W)
120
110 15 1,650
---
1,100 2,75050/ 60
10.5 2,200 1,400 3,30050/ 60
10.1 2,200 1,400 3,30050/ 60
9.6 2,200 1,400 3,30050/ 60
15 1,100 2,75050/ 60
220
230
240
Current (A)
GA7020/ GA7020S, GA7021: Assorted accessories for 180mm angle grinder
GA9020/ GA9020S: Assorted accessories for 230mm angle grinder

P 2 / 6
Repair
[2] LUBRICATION
Put approx. 60g of Makita grease SG No.1 in the gear room of Gear housing complete to protect parts and product from
unusual abrasion.
[3] DISASSEMBLY/ASSEMBLY
[1] NECESSARY REPAIRING TOOLS
CAUTION: Remove the wheel from the machine for safety before repair/ maintenance !
Model No. No load speed: min-1
GA7020
GA7020S 8,500
6,600
(USA, Guam: 6,000)
Spiral bevel gear 16 Spiral bevel gear 53B
Spiral bevel gear 53ASpiral bevel gear 12
GA9020
GA9020S
GA7021
Small spiral bevel gear
(Gear on Armature shaft)
Large spiral bevel gear
(Gear on Spindle)
Number of teeth: 16
Number of teeth: 12
Number of teeth: 53
Number of teeth: 53
1R048 Drill chuck remover 11 Removing Spiral bevel gear 53
1R049 Drill chuck remover 15 Removing Spiral bevel gear 53
1R269 Bearing extractor Removing Ball bearings
1R005 Retaining ring R pliers Removal/installation of Retaining ring R-42
Assembling Spiral bevel gear 531R165 Ring spring setting tool B
Code No. Description Use for
grooved
not grooved
[3] -1. Armature, Small spiral bevel gear, Ball bearing 6301DDW
Fig. 2
DISASSEMBLING
Fig. 1
Hex nut M8
1) After removing Carbon brush, separate the assembly of Gear housing complete with Armature from Motor housing
complete by unscrewing four M5x35 Tapping screws.
2) Separate Bearing box from Gear housing complete by unscrewing four M6x22 Hex socket head bolts.
3) With Armature securely held by hand, remove Hex nut M8 from the drive-end of Armature shaft by turning
counterclockwise with wrench 13. (Fig. 1)
4) Hold Small spiral bevel gear by hand, then pull off Armature from Gear housing complete. (Fig. 2)
Note: If it is difficult to pull off Armature by hand, do the following steps.
1. Lubricate small spiral bevel gear and Armature shaft with spray lubricant.
2. Wrap the gear with cloth to protect the gear teeth.
3. Using water pump pliers or the like, firmly grip the gear wrapped with cloth, then turn the gear.
Gear housing complete,
viewed from the wheel
installation side
Small spiral bevel gear
Important: As listed below, different gears are used for GA7020/GA7020S and GA9020/GA9020S/GA7021,
and they are not interchangeable between the models. Be careful not to confuse them.

P 3 / 6
Repair
[3] -1. Armature, Small spiral bevel gear, Ball bearing 6301DDW (cont.)
ASSEMBLING
DISASSEMBLING
Fig. 6
Ball bearing 6301DDW
1) Mount Ball bearing 6301DDW on Armature by hand, then insert
into the bearing installation hole of Gear housing, (Fig. 8)
Then pull off Armature.
2) Put Flat washer 20 onto Ball bearing 6301DDW, and fasten with
Retaining ring R-42.
3) Then do the reverse of the disassembling steps.
Fig. 3 Fig. 4
Fig. 5
Retaining rig R-42
Flat washer 20
Hex nut M8
Hex nut M8
Small spiral bevel gear
No.1R269
Ball bearing 6301DDW
Ball bearing 6301DDW
Ball bearing 6301DDW Ball bearing 6200DDW
5) In order to remove Ball bearing 6301DDW from gear housing complete, first remove Retaining ring R-42 with
Retaining ring R pliers RT-2N (No.1R005), and remove Flat washer 20 from Gear housing complete. (Fig. 3)
6) Reassemble Armature to Gear housing complete, then the spiral bevel gear to Armature shaft. Tighten Hex nut M8
provisionally by turning clockwise. (Refer to Fig. 2, 1)
7) By tapping the end of Gear housing complete with a plastic hammer, Ball bearing 6301DDW can be removed together
with Armature. (Fig. 4)
8) Remove Ball bearing 6200DDW from Armature with Bearing Extractor (No.1R269). (Fig. 5)
Small spiral bevel gear

P 4 / 6
Repair
[3] -2. Large spiral bevel gear and Ball bearing 6203DDW
DISASSEMBLING
Fig. 7 Fig. 8
1) Separate Bearing box from Gear housing complete by unscrewing four M6x22 Hex socket head bolts.
It is not necessary to remove Carbon brushes.
2) Remove Ball bearing 6000ZZ with Bearing Extractor (No.1R269). (Fig. 7)
3) Insert two Drill chuck removers (No.1R048, 1R049) between Large spiral bevel gear and Bearing box,
and set the Bearing box on the turn base of arbor press so that the wheel cover installation surface of
Bearing box is placed on the edge of the U-shaped notch of the turn base.
Then remove spindle by pressing down with arbor. (Fig. 8)
4) After removing Large spiral bevel gear, separate Bearing retainer 50
by removing three M5x16 Pan head screws. (Fig. 9)
5) Remove Ball bearing 6203DDW by hitting Bearing box straight down
against flat surface of work-bench. (Fig. 10)
If cannot be removed, use arbor press and a round bar for arbor of
an appropriate size as illustrated in Fig. 11.
Note: The gear and the ball bearing can be replaced without disassembling the Motor section.
Fig. 10 Fig. 11
Ball bearing
6203DDW
Round bar for arbor
No.1R269
U-shaped notch of arbor press
Ball bearing 6000ZZ
Bearing box
Drill Chuck Remover 11
(No.1R048)
Drill Chuck Remover 15
(No.1R049)
Spindle
Fig. 9
Pan head screw
M5x16 (3 pcs)
Bearing retainer 50
Large spiral bevel gear

P 5 / 6
Repair
[3] -2. Large spiral bevel gear and Ball bearing 6203DDW (cont.)
Fig. 12
Bearing box
[3] -3. Shaft Lock
Fig. 13
1) Remove Bearing box from Gear housing.
2) Pull off Shoulder pin 5 with pliers while pushing Pin cap with a
finger. (Fig. 13)
Note: Do not pull off shoulder pin 5 without holding pin cap because
Compression spring 12 would sling Pin cap.
Follow the reverse of disassembling steps.
Note: Do not reinstall removed Pin cap because removal of Shoulder
pin 5 damages the inside surface of Pin cap. Be sure to remove
plastic dust of Pin cap from Shoulder pin 5 and to install it onto
a brand-new Pin cap.
DISASSEMBLING
ASSEMBLING
Pin cap
Gear housing
Shoulder pin 5
Compression
spring 12
Do the reverse of the disassembling steps.
How to assemble Spindle to Large spiral bevel gear
See Fig. 12.
1) In order not to damage the gear teeth of Large spiral bevel gear, put it on Ring spring setting tool B (No.1R165).
2) After assembling Ball bearing 6203DDW to Bearing box, put Bearing box on Large spiral bevel gear.
3) Then press-fit Spindle into Large spiral bevel gear using arbor press.
ASSEMBLING
Spindle
No.1R165
diameter 40mm
diameter 58mm
Large spiral bevel gear
Turn over.

P 6 / 6
Circuit diagram
Wiring diagram
Field
Noise suppressor**
*Resistor is not used for GA7020, GA7021, GA9020
**Noise suppressor is not used for some country.
Power supply cord
Switch
[1] Motor Housing
[2] Handle
Color index of lead wires' sheath
Black
Red
Resistor*
Rib
Switch
Lead wire holder
[to Switch]
Power supply cord
Route two Field lead wires (black) as illustrated below.
Route through the hook.
Fix with the lead wire holder.
Be sure that the wires
are tight in this area.
Put Noise suppressor
in this portion if used.
Fix the following lead wires with the lead wire holder:
*two Field lead wires (black)
*two lead wires (red) of Resistor (if used)
Put Resistor in this portion
(Resistor is not used for
GA7020, GA7021, GA9020)
Route the lead wires of Power supply
cord between the rib and Switch.