Makita Maktec MT904 Manual

* With Inner flange, Lock nut, Wheel cover, and Side grip
Model No.
Description
CONCEPT AND MAIN APPLICATIONS
Specification
Dimensions: mm (")
Width (W)
Height (H)
Length (L)
Model No. MT904 MT905
361 (14-1/4)
140 (5-1/2) 171 (6-3/4)
124 (4-7/8)
MT904/ MT905
Angle Grinders 125mm (5") /150mm (6")
Moldes MT904/ MT905 are easy to handle, lightweight maktec Angle grinders.
Their features are as follows:
• Similar performance as Makita GA5010/GA6010
• New cosmetic design
• Industrial performance and durability at less expense
Standard equipment
Note: The standard equipment may vary by country or model variation.
Side grip ........................................................1
Lock nut wrench ............................................1
Optional accessories
Wheel cover
PRODUCT
P 1/ 10
Weight according to
EPTA-Procedure 01/2003*: kg (lbs) 2.8 (6.1) 2.8 (6.2)
Double insulationProtection against electric shock
2.0 (6.6)Power supply cord: m (ft)
No load speed: min.ֿ ¹= rpm
Diameter
Hole diameter
11,000 10,000
MT904 MT905
Specification Model
240 4.6 50/60 1,050 1,700
Continuous Rating (W)
Voltage (V) Cycle (Hz) Input Output
700
Max. Output (W)
110
120
220
230
10
10.5
5
4.8
50/60
50/60
50/60
50/60
1,050
1,050
1,050
1,700
1,700
1,600
1,600
Current (A)
900---
700
700
700
Wheel size:
mm (") Max. thickness
125 (5)
22.23 (7/8)
150 (6)
6 (1/4)
TECHNICAL INFORMATION
OFFICIAL USE
for ASC & Sales Shop
L
W
H

P 2/ 10
Repair
[3] DISASSEMBLY/ASSEMBLY
[1] NECESSARY REPAIRING TOOLS
CAUTION: Repair the machine in accordance with “Instruction manual” or “Safety instructions”.
Code No. Description Use for
removing / assembling Ring spring 13 from / to Spindle
removing Ball bearing 6202DDW from Bearing box
holding Spindle when assembling large Spiral bevel gear
[2] LUBRICATION
Important: As listed below, different gears are used for MT904/ MGA504 and MT905/ MGA600, and they are not
interchangeable between the models. Be careful not to confuse them.
Apply Makita grease N. No.1 to the following portions designated with the black triangle to protect parts and product
from unusual abrasion.
Fig. 1
Item No.
Model No.
MT904/
MGA504
MT905/
MGA600
No load speed
(rpm)
Small spiral bevel gear
(Gear on Armature shaft)
Spiral bevel gear 11 Spiral bevel gear 35A
Number of teeth : 35
Number of teeth : 11
Spiral bevel gear 11A Spiral bevel gear 38
Number of teeth : 38
Number of teeth : 11
11,000 rpm.
10,000 rpm.
Large spiral bevel gear
(Gear on Spindle)
Description Amount
18g approx.
a little
Portion to lubricate
1R004 Retaining ring pliers ST-2
Bearing setting pipe 20-12.2
Baring setting plate 15.2
1R028
1R035
1R037
1R268
1R269
1R280
1R291
1R350
Bearing setting plate 20.2 assemble large Spiral bevel gear to Spindle
Spring pin extractor M3 disassembling Spindle lock mechanism
Bearing extractor removing Ball bearings 608ZZ and 696ZZ
removing Spindle from large Spiral bevel gearRound bar for Arbor 6-50
Retaining ring S and R pliers removing / assembling Retaining ring R-26
Ring 60
Spiral bevel gear
(small) Ball bearing 6000DDW
Retaining ring R-26
4
support Gear housing when disassembling Spindle lock
5
4 Gear housing Gear room where small and large Spiral bevel gears engage.
5 O ring 26 whole portion
grooved
not grooved

P 3/ 10
Repair
[3] DISASSEMBLY/ASSEMBLY
[3] -1. Armature, Spiral bevel gear (small), Ball bearings 6000DDW, 608ZZ
DISASSEMBLING
Wrench 11
1. Remove Carbon brush.
(1) Disassemble Armature and small Spiral bevel gear from Gear housing as drawn in Fig. 2.
2. Remove four M5x18 Pan head
screws, then separate Bearing
box section from Gear housing.
3. Remove four 5x25 Tapping screws,
then separate Gear housing from
Motor housing.
4. While holding M7 Hex nut with Wrench 11, turn Armature counterclockwise to remove the nut
from Armature assembly.
5. Pull off Armature from Gear housing while holding
small Spiral bevel gear by hand so that the gear
does not fall off from Gear housing.
6. Remove small Spiral bevel gear from
Gear housing.
Small Spiral bevel gear
Armature
Armature
Spiral bevel gear
(small)
Note in Disassembling:
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 a 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.
M7 Hex nut
M7 Hex nut
Fig. 2
Small Spiral bevel gear
Carbon brush (2 pcs.) M5x18 Pan head
screw (2 pcs.)
Motor housing
Gear housing
M5x25 Pan head
screw (4 pcs.)
Bearing box
Gear housing

P 4/ 10
Repair
[3] DISASSEMBLY/ASSEMBLY
[3] -1. Armature, Spiral bevel gear (small), Ball bearings 6000DDW, 608ZZ (cont.)
DISASSEMBLING
1. Remove Retaining ring R-26 with 1R291. 2. Reassemble Armature to Gear housing, then small Spiral
bevel gear to Armature shaft. Tighten M7 Hex nut
provisionally by turning it clockwise.
1R291
Retaining
ring R-26
Ball bearing 6000DDW
(2) Remove Ball bearing from Gear housing as drawn in Fig. 3.
3. Remove Ball bearing 6000DDW together with Armature assembly by tapping the end of Gear housing with
a plastic hammer,
4. Removing M7 Hex nut, small Spiral bevel gear and
Ball bearing 6000DDW from Armature assembly.
Fig. 3
M7 Hex nut
small Spiral
bevel gear
Armature
Armature
M7 Hex nut
small Spiral bevel gear
Ball bearing 6000DDW Ball bearing 608ZZ 1R269
6. Remove Ball bearing 608ZZ with 1R269.

P 5/ 10
Repair
ASSEMBLING
Armature
(1) Use Armature as a tool for Ball bearing assembling. See Fig. 4.
(2) Assemble Gear housing section as drawn in Fig. 5.
Ball bearing
6000DDW
1. Mount Ball bearing 6000DDW
on Armature assembly by hand.
3. Snap Retaining ring R-26 into
the groove of Gear housing.
2. Insert Ball bearing 6000DDW on Armature
assembly into the bearing installation hole
of Gear housing. Then, Pull off Armature.
Ball bearing
6000DDW
Switch trigger
Switch trigger
Spindle
1. When assembling Gear housing to Motor housing,
face Bearing box installation side toward Switch trigger.
2. Assemble Bearing box section to Gear housing
with four M5x18 Pan head screws.
Ball bearing
6000DDW
Retaining ring R-26
Groove of
Gear housing
Fig. 4
Fig. 5
Bearing box
installation side
Bearing box
[3] DISASSEMBLY/ASSEMBLY
[3] -1. Armature, Spiral bevel gear (small), Ball bearings 6000DDW, 608ZZ (cont.)
M5x18 Pan head
screw (4 ps.)

P 6/ 10
Repair
[3] DISASSEMBLY/ASSEMBLY
[3] -2. Large Spiral bevel gear, Spindle, Ball bearings 696ZZ / 6202DDW
DISASSEMBLING
(1) Disassemble Bearing box section and replace the parts as drawn in Fig. 6.
Note: It is not necessary to remove Carbon brushes.
3. While expanding Ring spring 13
with 1R004, pry and remove it
from Spindle with a slotted
screwdriver.
4. Put Bearing box on U-shaped portion of
Arbor press table. Then, give impacts to
Spindle with Arbor press carefully until
the pressfit is released.
6. Remove three M3x6 Pan head screws
and Bearing retainer 39 from Bearing
box.
7. Put Bearing box onto 1R350. Then, press down Flat washer 15
and Ball bearing 6202DDW from Bearing box with 1R028.
Note: Ball bearing 6202DDW is damaged by the removal process.
Do not reuse the removed one.
5. Press down Spindle from Bearing box section with 1R280.
Then, remove large Spiral bevel gear from Bearing box.
Fig. 6
1. Unscrew four M5x18 Pan head
screws, then, separate Bearing
box section from Gear housing.
2. Remove Ball bearing
696ZZ with 1R269.
1R269
Ball bearing
696ZZ
M5x18 Pan head
screw (4 pcs.)
Bearing box
section
1R004
Ring spring 13
slotted screwdriver
1R280
Spindle
large Spiral
bevel gear
Bearing
retainer 39
Bearing
box
Bearing box
1R028
1R350 Ball bearing
6202DDW
Flat washer 15
M3x6 Pan head
screw (3 pcs.)

P 7/ 10
Repair
[3] -3. Shaft Lock
ASSEMBLING
DISASSEMBLING
(1) Assemble Flat washer 15. Then, assemble a new Ball bearing 6202DDW. (Refer to the bottom right in Fig. 6.)
(2) Secure Ball bearing 6202DDW by fastening Bearing retainer 39 with three M3x6 Pan head screws.
(Refer to the bottom left in Fig. 6.) And then, assemble Spindle to Bearing box.
(3) Assemble large Spiral bevel gear to Bearing box as drawn in Fig. 7.
Gear teeth
(4) Assemble the rest of parts by reversing the disassembly procedure. (Refer to Fig. 6.)
Fig. 7
1R037
large Spiral
bevel gear
1R035
When large Spiral bevel gear is pressfit into Spindle:
1. insert the thread of Spindle into the hole of 1R035.
2. put 1R037 on the gear teeth of large Spiral bevel gear and then press it down carefully so that
the gear teeth do not damage.
(1) Disassemble Gear housing from Motor housing, and pull off Armature from Gear housing. (See Fig. 2.)
(2) Disassemble Shaft lock from Gear housing as drawn in Figs. 8 and 9.
Apply 1R268 to Shoulder pin 5 through the small hole
on Pin cap and tap 1R268 with a metal hammer.
Shoulder pin 5 is removed from Gear housing.
Remove 1R268 from Pin cap carefully
so that Pin cap is not slung
by Compression spring 8.
Shoulder pin 5
Pin cap
Pin cap
Pin cap
Compression
Spring 8
1R268
1R350
Fig. 9Fig. 8
[3] DISASSEMBLY/ASSEMBLY
[3] -2. Large Spiral bevel gear, Spindle, Ball bearings 696ZZ / 6202DDW (cont.)
Note: Remove some plastic dust
on this area before reassembling.
Note: Do not reuse the removed Pin cap
because the removal one damages
the inside of the cap.

P 8/ 10
Repair
[3] DISASSEMBLY/ASSEMBLY
[3] -3. Shaft Lock (cont.)
ASSEMBLING
(1) Be sure to use a new Pin cap for replacement and to eliminate all the plastic dust on Shoulder pin 5. (Fig. 10)
(2) Assemble the parts for Shaft lock mechanism as drawn in Fig. 11.
Fig. 10 Fig. 11
Plastic dust
Shoulder pin 5
Shoulder pin 5
2. Assemble Pin cap by pressing it
to Shoulder pin 7.
Note: Do not forget to assemble
Compression spring 8.
1. Insert Shoulder pin 5
through the hole of
Gear housing complete.
Pin cap
Compression
spring 8

P 9/ 10
Fig. D-1
Circuit diagram
White
Switch
Power supply cord
Circuit diagram of Switch
White lead wire is used
for some countries
instead of blue.
Black lead wire is used
for some countries
instead of brown.
Noise suppressor is not used
for some countries.
Noise
suppressor
1 2
1 2
Blue
Brown
Color index of lead wires' sheath
Black
Field
Lead wire
(black, 18AWG*)
Lead wire
(white, 20AWG*)
AWG*: American wire gauge
[View from Commutator side]
1
2
1
2

P 10/ 10
Wiring diagram
Route Field lead wires through
the opening of Motor housing while
tightening them in the housing.
Fig. D-2
Fig. D-3
Wiring from Motor housing Wiring to Switch
Lead wire
holder
Spindle
Rib A
Rib B
Inner wall
Noise suppressor (if it is used.)
Opening
A
Lock-on button
B. Connect terminals of Power supply cord
to Switch while facing their wire connected
portion to Cord guard.
Put Noise suppressor on Field lead wire.
A. Connect terminals of Field lead wires to
Switch while facing their wire connected
portion to Motor housing.
Field lead wires
Noise suppressor
Lead wires of
Power supply cord
B
Wiring in Handle set
Fix this Field lead wire
in this Lead wire holder.
Inflect these Connectors
so that Lead wires do not
interferes with the other
connectors on the same line.
Fix Field lead wires in this
Lead wire holder.
Note: Don’t slack these wires.
Route Lead wire (brown or black) of
Power supply cord between Rib B
and Inner wall of Handle set.
Route Field lead wire and one of
Lead wire of Noise suppressor
between Rib A and Inner wall
of Handle set.
Tighten Field lead wires
in Motor housing by pulling
out them to Handle section.