"Directed Power" Axle - Lincoln Continental 1964 Shop Manual

(063)
tion, removal and installation of the
differential assembly and drive pin-
ion. A metal tag, stamped with the
gear ratio plus the number of teeth
on the ring gear and pinion, is se-
cured to the housing by one of the
cover bolts.
Cars equipped with "Directed
Power" differential assemblies will
have an additional metal tag iden-
tification attached to one of the
cover bolts.
Ball bearing assemblies (rear
wheel bearings) are pressed onto
the outer ends of the axle shafts and
set in the outer ends of the axle hous-
ing. These bearings support the semi-
floating axle shafts at the outer ends.
The inner ends of the shafts spline
to the differential side gears. Bearing
retainer plates hold the shafts in the
housing. The axle shafts are equal
in length and arc, therefore, inter-
changeable.
OPERATION
The rear axle drive pinion receives
its power from the engine through
the transmission and drive shaft.
The pinion gear rotates the differen-
tial case through engagement with
the drive gear, which is bolted to
the case outer flange. Inside the
case, two different pinion gears are
mounted on the differential pinion
shaft which is pinned to the case.
These pinion gears are engaged with
the side gears, to which the axle
shafts are splined. Therefore, as the
differential case turns, it rotates the
axle shafts and rear wheels. When
it is necessary for one wheel and
axle shaft to rotate faster than the
other, the faster turning side gear
causes the pinions to roll on the
slower turning side gear to allo"'
differential action between the two
axle shafts.
"DIRECTED POWER" AXLE
DESCRIPTION
The "Directed Power" axle is the
same as the conventional axle with
respect to the ring gear and pinion.
the bearings, the housing, and the
axle shafts. The difference is in the
differential assembly.
The differential is of a two-piece
case design (Fig. 23). Each case halt
PART 4-2-REAR AXLE:
has an identical clutch assembly
which connects one of the axle shafts
directly to the case half as driving
conditions demand. Each clutch
pack consists of five steel
platt~s
set
between the case and the side gear
ring. The two outer plates and the
center plate are locked to the. dif-
ferential case half by external lugs.
The remaining two plates (discs)
have internal spline teeth which lock
to the splined hub on the side gear
ring. The external lug plate and the
spline disc plate that are located next
to the case half are spring plates,
which are installed with the convex
(bowed) side against the case. The
side gear ring is internally splined
to the axle shaft and acts as a pres-
sure plate against the clutch pack.
Unlike the single pinion shaft of
the conventional unit, the two pin-
ion mate shafts are not rigidly at-
tached to the differential case, nor
are they attached to each other. At
both ends of the mate shafts, there
are two flat surfaces so arranged that
they form a "V" which mates with
corresponding "V" shaped surfaces
(ramps) cut in the shaft openings of
the differential case.
OPERATION
The "Directed Power" axle has a
power flow identical to the conven-
tional rear axle, plus a more direct
power flow which automatically takes
effect as driving conditions demand.
This more direct power flow is from
the differential case to each axle
shaft through clutches.
The mate shafts are assembkd in
the case with enough clearance so
that when the case tries to rotate
the mate shafts and the mate shafts
resist rotation, they will be forced to
hear against one side of their "V"
ramps. Since the two "V" ramps
of one mate shaft point in a di-
rection opposite to that of the two
"'V" ramps of the other mate shaft,
the two shafts with their pinions
will be forced apart as they resist
rotation. This mate shaft movement
compresses the clutch pack through
the pinion gears and side gear rings.
When the differential case rotates
in the opposite direction, the mate
shafts will be forced to bear against
4-7
the opposite side of their "V" ramps
and will again be forced apart to
apply against the clutch packs. There-
fore, since the ramps are "V" shaped,
the clutches will apply during either
forward or reverse operation. Like-
wise, the clutches will apply whether
the power flow is from the differen-
tial case to the axle shafts, or from
the axle shaft to the differential case.
The amount of compression on
the clutch plates will be proportion-
ate to the load applied to the dif-
ferential case and the resistance to
turning offered by each mate shaft.
For example, if the car is driven
straight ahead and the traction or
load on both wheels is equal, both
mate shafts will give equal resistance
to the rotating differential case and
will thus bear against their respective
ramps with equal force. This equal
movement of the mate shafts will
cause them to exert equal pressure
against both right and left-hand
clutch packs. Both axle shafts will,
therefore, be locked directly to the
case with equal force.
Clutch application prevents mo-
mentary spinning of one of the
wheels when it leaves the road be-
cause of a bump, or encounters poor
traction because of a slippery road.
Under these conditions, even though
the traction load is relieved on the
one wheel, the acceleration load is
simultaneously applied to the dif-
ferential case as the engine tries
to spin the wheel.
When the rear axle is in a turn,
the appropriate clutch releases auto-
matically to allow normal differ-
ential operation as required. In the
straight ahead position, the differ-
ential case is driving both wheels
and thus applies an equal load
against both mate shafts. Since both
mate shafts offer resistance to this
load, both clutches are applied. On
a turn, however, the outside wheel
turns faster than the inside wheel.
The outside wheel, instead of being
driven by the case, now tends to
drive the case. With the power thus
relieved, the differential case releases
its load against the outside wheel
mate shaft which, in turn, releases
its pressure against the outside
wheel clutch pack. With the clutch
released, normal differential action
will take effect.