Operating, Dismantling & assembly instructions, Reassembly – Universal Air Tools UT8905 User Manual
Page 2: Safety rules for a screwdriver

Operating
Select the correct screwdriver bit or fastener driver to suit the screw or
fastener to be tightened or loosened. Insert appropriate drive bit.
This screwdriver has an adjustable clutch so that the torque applied to
the fastener can be adjusted to give the required tightness within the
torque range of the tool. To set the tool to give a particular torque
output, turn the torque ring (57) to the right to increase the torque
output or to the left to decrease the torque output. This screwdriver has
a push to start system which eliminates the use of a throttle lever, the air
motor will automatically stop when the screwdriver reaches the pre-set
torque
If the fastener is not sufficiently tightened or cannot be loosened then
the tool in adjustable clutch mode has insufficient capacity. Select a
more powerful tool.
The person setting up the tool must be aware of this torque reaction at
high setting levels of the clutch and that the tool will try to turn against
the hand. All that is required is a firm grip.
The only thing that will affect the output is a change in the air supply
pressure. The output can be increased up to the use of the maximum
allowed supply pressure and decreased with a reduction in supply
pressure until the tool fails to operate.
It must also be understood that even if the clutch is set to slip it may not
do so if the supply air pressure falls below the pressure at which the
clutch was set. It is therefore strongly recommended that a pressure
control valve is used. Information as to suitable equipment can be
obtained from your supplier.
When using the tool keep the screwdriver bit pressed firmly into the
screw head to avoid cam out and screw head damage.
Dismantling & Assembly Instructions
Disconnect from air supply
Grip the tool in a vice fitted with soft jaws on the flats at the rear end of
the centre housing (25). Take off soft cover (65) and rear housing (62)
Remove snap ring (61) take off bit slide (60) spring (58) torque ring (57)
regulation washer (56) and needle pins (55) Unscrew clutch housing
(54) left hand thread and remove anvil bushing (53) washer (52) torque
spring (51) spring (45) and slide base (46) When removing anvil (43)
take care not to lose ball (59 & 44) Take off snap ring (50) and remove
ball race (49) ball (48) end clutch (47) centre clutch (41) ball (42) rear
clutch (39) pilot pin (38) ball (37) and retainer (36) Take off snap ring
(40) and remove ball bearing (26) From the centre housing remove
second gear cage (23) and take off second plant gear (22) and second
main gear (21) then remove first gear cage (20) and take off first plant
gear (19) then remove internal gear (24) and E ring (15) and first main
gear (18) Take off suspension ring (64) and coloured ring (66) unscrew
housing nipple (63) and air inlet bushing (35) remove second silencer
(34) cone spring (33) valve plate (31) O-ring (30) exhaust deflector (29)
first silencer (28) operating rod (32) and O-ring (27) Remove set screw
(4) and take off switch (5) Unscrew end housing (1) and remove O-ring
(2) and valve (3) Pull out air motor from housing (25) tap end of rotor and
remove front plate (13) take out roll pin (8) and remove end plate (7)
Remove from end plate (7) roll pins (9) and bearing (6) Take out rotor
(11) from cylinder and remove rotor blades (12)
Reassembly
Clean all components and examine for wear and tear. Look in particular
for wear and cuts on O-rings, wear on rotor blades, gears and clutch
components. Coat all parts with pneumatic tool lubrication oil, one
preferably containing a rust inhibitor and grease all bearings, gears and
clutch parts with a molybdenum or lithium based general purpose
grease. Before reassembling the motor, make sure that the faces of end
plate (7) & (13) that abut cylinder (10) are flat and free from burs. If
necessary lap on a flat fine grade of abrasive paper. Reassemble in the
reverse order. When refitting the complete motor assembly to the
centre housing (25) first make sure that the motor assembly is clamped
tightly together and that the rotor spins freely, slide the motor assembly
into the centre housing (25) ensuring that roll pin (8) locates in the
motor assembly and in the hole in the bottom of the main bore of centre
housing (25) situated between the two main ports. Reset the clutch as
required and /or set the correct air pressure.
(5ml) of a suitable pneumatic motor lubricating oil preferably
incorporating a rust inhibitor. Reconnect tool to air supply and run tool
slowly for a few seconds to allow air to circulate the oil. If tool is used
frequently lubricate on daily basis and if tool starts to slow or lose power.
It is recommended that the air pressure at the tool whilst the tool is
running is 90 p.s.i./6.3 bar. The tool can run at lower and higher
pressures with the maximum permitted working air pressure of 100
p.s.i./7.0 bar.
Page No 2
Safety Rules For A Screwdriver
1) Read all the instructions before using this tool. All operators must be
fully trained in its use and aware of these safety rules.
2) Do not exceed the maximum working air pressure.
3) Use personal safety equipment.
4) Use only compressed air at the recommended conditions.
5) If the tool appears to malfunction remove from use immediately and
arrange for service and repair.
6) If the tool is used with a balancer or other support device ensure that
it is fixed securely.
7) Always keep hands away from the working attachment fitted to the
tool.
8) The tool is not electrically insulated. Never use the tool if there is any
chance of it coming into contact with live electricity.
9) Always when using the tool adopt a firm footing and/or position and
grip the tool firmly to be able to counteract any forces or reaction forces
that may be generated whilst using the tool.
10) Use only correct spare parts. Do not improvise or make temporary
repairs.
11) Do not lock, tape, wire, etc. the on/off valve in the run position. The
trigger/lever etc. must always be free to return to the 'off' position when
it is released.
12) Always shut off the air supply to the tool, and depress the
trigger/lever etc. to exhaust air from the feed hose before fitting,
adjusting or removing the working attachment.
13) Check hose and fittings regularly for wear. Replace if necessary. Do
not carry the tool by its hose and ensure the hand is remote from the
on/off control when carrying the tool with the air supply connected.
14) Take care against entanglement of moving parts of the tool with
clothing, ties, hair, cleaning rags, etc. This will cause the body to be
drawn towards the tool and can be very dangerous.
15) It is expected that users will adopt safe working practices and
observe all relevant legal requirements when installing, using or
maintaining the tool.
16) Do not install the tool unless an easily accessible and easily operable
on/off valve is incorporated in the air supply.
17) Take care that the tool exhaust air does not cause a problem or
blows on another person.
18) Never lay a tool down unless the working attachment has stopped
moving.
19) Always ensure that the reverse button is in the selected position
before starting the tool.
20) Do not use bits or sockets with excessive wear to the input and
output drives. Make sure the bit, socket, extension is firmly fixed to the
tool.
21) When loosening fasteners first ensure that there is sufficient
clearance behind the tool to avoid hand entrapment. The tool will move
away from the threaded joint as the nut/bolt is loosened and rides up
the thread moving the tool with it.