IBM Selectric Reference Manual

Adjust Linkage
Keyboard Lock
No
Shift Clutch o.·erdrives 4.2
Shift Link Bent
No
SHIFT OR ENTER
Yes
No
Interlock Adj ustment 4.3
Filter Shaft 4.6
Cycle Shaft Overthrow 4 .. 5
Figure 4.0
4.0
4.1
4.2
4.3
4.4
4.5
4.6
4.7
SHIFT OR ENTER
Shift (or Enter) Adjustments
The
shaft end play should be .002" - .004". If the
Shift Arbor comes loose, a new set screw is avail-
able (PN 257969) whi ch will lock the arbor securely
on the shaft.
The Shift Ratchet should rotate .028" - .059" when
released. Under power, the Shift Cam should reach
a detented position with the detent held away from
the Shift Cam. See S . H. 4. 10 .
.
040"- .060" clearance between the ratchet and the
interlock .. Adjust the Interlock Cam.
. 002" - .OOS" clearance between the Upper Case
(U.C.) Armature and the Release Arm Pin. See S. H.
4.9.
The cycle shaft overthrow should be~ .007" to .015"
(l to 3 degrees).
With an interposer latched down and the Fi Iter Shaft
Gear held in a driven direction, there should be .010'
- .015" clearance between the Interposer and the
Fi Iter Shaft Blade. If the fi Iter shaft timing is wrong,
the Shift Interlock Cam shou Id be checked and read-
justed. (Adjustment 4.3).
Binds in the Shift Cam may be causled by maladjust-
ment of the Shift Back-up Roller. Adjust for .002" -
.004" clearance between the cam in lower case. A
Spri ng Hook Pusher end may be used to adj ust the
Back-up Roller eccentric stud.
4.S
4.9
5-7
No
Yes
Yes
Armature to
Release Lug Clearanc;-4A J
Yes
-]
Shift Arbor Loose or Worn 4. 1
Spring Clutch Broken
Cam Binds
4.8
Ratchet Binds or C Clip Missing 4.7
S. H. SHIFT LOCK-UP IN UPPER CASE
There is a possibi lity that the shift mechanism may
lock when
shifted to an upper case position, prevent-
ing release to lower case from the keyboard. This is
caused by an accumulation of grease on the shift re-
lease arm stud and the upper case armature. When the
shi ft re lease arm trave Is to an upper case posi ti on,
the grease accumulation puHs the upper case armature
along with it. The armature is then latched in upper
case position, holding the shift mechanism in upper
case. Any attempt to un lock it from the keyboard
is futi Ie since the lower case armature must first be
activated to un latch the upper case armature .
On the next inspection or when this trouble occurs,
the shift release arm and upper case armature shou Id
be cleaned thoroughly of all grease .
S.H. SHIFT CLUTCH SPRING ADJUSTMENT
1. Install shift clutch spring; allow the retaining
plate screws to remain loose.
2. Place shift cam in Upper Case position and hold
in
detented position.
3. Insta 1\ clutch ratchet (Upper Case posi ti on) 50
that it~ lug is toward the front of the machine
ahead of the re lease arm lug.
4. Manually rotate the ratchet (clockwise) until
the shift release arm lug now lies directly under
the middle of the clutch ratchet lug. The shift
clutch spring and retaining plate will slip to a
new positi on as this
is accomplished.

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