1938 LaSalle Production - GM Heritage Center

Cadillac-LaSaile Preliminary Service Information 17
to which the rods from the control shafts are
attached; while on the inner end a shoe on an inner
lever contacts the high and intermediate
shifter disc, and the shoe on the other lever shifts
the low and reverse sliding gear.
Inasmuch as shifter shafts are not employed with
this construction, the shifter locking balls operate
against notched quadrants on the inner shifting
levers as shown in Fig. 17. The locking ball pin
and spring are carried in a drilled passage in the
transmission case; the ball for the low and reverse
lever is carried at one end of the spring and the ball
for the high and intermediate lever at the other.
Fulcrum Point
Lug for IniK- Shaft 4 • .-.V^
Hi,hand 5" d l J^V,.w
Gears {^V"^- " 1 *
Luy for Outer Tuba
Low .11)--1 Re^'r^ C
Cro^s-over
Spring
SU:enn„, Sli Jft
• hiftun] L«rwi
Fig. 16. Transmission control lever pivot and cross-over
mechanism (all 38-series)
Operation of the transmission is virtually unchanged.
The control lever knob is lifted and
moved rearward to engage low gear or forward to
engage reverse; similarly, it is depressed and moved
forward or rearward to engage second and high
gears respectively.
Lifting the knob lowers the inner end of the
pivot (Fig. 16) so that the slot in the underside
engages the lug for the outer torsion shaft, from
which the linkage leads to the low and reverse
shifter gear. Depressing the knob raises the pivot
so that the upper slot engages the lug for the inner
shaft, which connects with the high and intermediate
coupling.
The same transmission gear case is used on all
38-series cars including the 38-90 V-16. The 38-50
LaSalle uses one length of transmission mainshaft
and extension housing, while a second length is
used on all Cadillac series. AH transmission parts
are, therefore, completely interchangeable within
the 38-series except the mainshaft and extension
housing.
Minor changes have been made in the transmission
to increase its load carrying capacity.
Among these are the use of new aluminum alloy
synchronizing drums, a j^-inch increase in countershaft
diameter, requiring 28 rather than 26 needle
bearings at each end of the shaft, and an increase
of ^-inch in the clutch connection diameter.
Service Operations.—Removal and disassembly
procedures for the shifting levers and mechanism
will be apparent from inspection. Reassembly
operations, will, however, require the following
precautions:
Reassemble the mechanism in order from the
lever at the steering wheel down to the transmission.
The lever at the lower end of the inner torsion
shaft is splined so that it can be installed in two
possible positions which are about 10 degrees
apart. Install this lever in the upper position on
38-75 and 90, and in the lower position on 38-50,
60 and 65. This will avoid interference with the
steering column.
The levers at the outer ends of the transmission
shafts also can be installed in two positions. Install
them in the upper positions on all series.
Make sure both levers are in neutral when installing
the rods that connect with the torsion shafts
at the steering column.
When installing these rods, adjust the rod ends
so that the neutral position of the control lever
knob is approximately 2 inches above the steering
wheel center line, as shown in Fig. 15. Adjust
the rod lengths carefully so that the lugs for the
inner and outer torsion rods (Fig. 16) are exactly
in line in the neutral position; otherwise, it will
be impossible to cross over from low and reverse
to high and intermediate.
Removal and installation of the complete transmission
is the same as for the 37-series V-8's, after
the shifting rods have been disconnected. The
levers must also be removed on 38-60. It is not
necessary to disturb the floor or toe-boards on any
38-series cars.
Disassembly and reassembly follow the same
general procedures, except that there are no shifter
shafts to remove, and the inner shifting levers and
quadrants and the lock balls, pin and spring arc
removed after the gears have been taken out of
the case.
Fig. 17.
Low and Reverse
Shifter Gear
Locking Balls
Spring and Pin
Phantom view of gear shifting mechanism in
transmission (all 38-series)