IBM Selectric Service Manual

A new check pawl has now been released for use on
the SELECTRIC I/O Printer with an improved engaging
surface. The new check paw I is easi Iy identifiab Ie
from the old one by the deepened notch at the check-
i ng area. An i Ilustrati on is shown be low:
Figure J5.3
This fai lure wi II usua Ily occur at one point on the
cycle shaft; the shaft will latch on one cycle and
fai I to latch on the next cyc Ie, and it is easi Iy ob-
served. It may sti II be necessary to increase the
spring tension by either forming the spring tip down
at a 45° angle, or by winding the check pawl spring
up
one additional turn. Increasing the spring tension
wi II, however, acce lerate wear of the check paw I
and ratchet.
If a prob lem is encountered where the cyc Ie shaft
will not reliably detent, even after the check pawl
has been rep laced and the spri ng has been wound up,
it will then be necessary to replace the entire cycle
shaft assemb I y .
The
PN J J 23675 wi II remain the same.
J5. J J CYCLE CLUTCH SLIPPAGE
Slow or sluggish cycle operation may be encountered
due to the cycle clutch spring slipping or the sleeve
binding. This condition may be detected during re-
peated +5 ti It 3 selection. The following areas
should be checked if this occurs.
J. Excessive cycle shaft end play - end play should
be .OOJ" to .003".
2. Oi I on spring - the proper lubrication for the
spring is #23 grease. Any oil on the spring will
ollow slippage; the spring must be removed and
thoroughly cleaned with IBM cleaning fluid.
Care shou Id be taken to remove a II traces of oi I
from the cyc Ie shaft reservoi r area and a Iso the
cycle pulley hub. The whole assembly should be
relubricated thoroughly with #23 grease.
3. Incorrect adjustment of cyc Ie clutch spring.
a. Opening of the spring too soon wi II cause
slippage.
b. The cycle clutch spring should be adjusted
left or right to maintain .005" clearance be-
tween the spring and pu Iley hub. Excessive
clearance wi II not allow enoug h engagement
of the spring on the hub, causing slippage.
Too little clearance wi II caus.e the spring to
bind against the pulley hub and overload the
clutch release train, giving rise to sluggish
keyboard reaction as well as noisy idling.
c. The cycle clutch collar should be adjusted
left or right to allow a minimum of .008" end
play of the clutch sleeve. Too little play of
the sleeve can resu It in erroneous readings of
the cyc Ie shaft end p lay (where the sleeve
p lay substitutes for the shaft p lay) and cause
a di rect mechanism drive connecti on between
cycle pulley and shaft. This latter condition
wi II prevent a comp lete closure of the cyc Ie
spring and result in slippage.
4. Worn spring (J5.5).
J5.12 CYCLE CLUTCH LATCH BREAKAGE
4-23
We have received several reports of the cycle clutch
latch breaking in the area of its pivot point. This
breakage is due to forming the cycle clutch latch
extension which mounts the restoring roller. When a
cycle clutch latch is mounted in the SELECTRIC I/O
Printer, it has a tendency to mount non parallel to
the sleeve angling to the left. This creates a problem
wherein the cycle clutch latch restore roller will con-
tact the cycle clutch collar mounting screw. The
past fix for this problem was to form the cycle clutch
latch extension to the right so it wou Id track the
cam properly. This method of adjustment wi II break
the cyc Ie clutch latch extension or wi II break the
cycle clutch latch at its pivot point since the latch is
a
hardened part. This method of adjustment a Iso fai Is
to make the cycle clutch latch parallel to the cycle
clutch sleeve.
The proper adjustment of this mechanism is as follows:
The
duckbill pliers should be inserted at the point
where the cyc Ie clutch latch bracket mounts to the
selector bail mounting bracket. The pliers can then
easi Iy move the entire cyc Ie clutch latch bracket to
the left or right by a twisting motion. This will en-
sure that the latch is para lie I to the sleeve and it
will also ensure that the restore roller moves far e-
nough to the right so as not to contact the screw in
the cycle clutch collar.
This procedure is presently being used on the I/O
Assembly Line, with excellent results. It is very
possib Ie, however, that there are many SELECTRIC
I/O Printers in the field whose latches were formed
using
the old method. It is possible that breakage of
those cyc Ie clutch latches wi II resu It. They shou Id
be replaced using a hardened latch and the new ad-
j ustment procedure fo I lowed .
The
cyc Ie clutch latch assemb Iy part number is
J
135J24.

IBM Selectric Specifications

General

Type	Electric typewriter
Introduced	1961
Keyboard Layout	QWERTY
Carriage Return	Electric
Manufacturer	IBM
Printing Technology	Typeball (golf ball)
Power Source	AC Power
Power Supply	120V AC