1938 LaSalle Production - GM Heritage Center

Hotchkiss Drive
The Cadillac-LaSaile Hotchkiss drive contributes to
riding comfort by allowing the rear wheels to follow
road irregularities freely. Starting and stopping strains
are cushioned by the rear springs, and smooth rear axle
action over rough roads is attained. Unsprung weight is
reduced to a minimum.
The torque tube or torque arm drive used on some
cars aggravates harsh riding because rear wheels are
held inflexibly to the drive line. This construction ties
the whole rear axle and propeller shaft assembly rigidly
to the transmission frequently causing severe breakage
to all parts in accidents involving a rear wheel and axle.
In an attempt to reduce the amount of unsprung
weight, coil type rear springs may be used in conjunction
with torque tube drive or its equivalent instead of leaf
springs. Cadillac engineers believe the Hotchkiss drive
to be so superior to torque arm or tube inflexible construction
that they prefer the leaf spring design. In fact,
with rear wheels supported by the springs Cadillacs
and LaSalle still have far less unsprung weight than
the torque tube with coil springs.
With coil rear springs the wheels are still supported
by the torque arm, hence this method cannot be called
an independent rear suspension.
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