Milton CAT 990H - Manual (Page 5)

1 Impeller Clutch. Modulates the amount
of engine power sent to the wheels.
2 Lock-Up Clutch. Provides direct drive for
improved fuel economy. With Electronic
Clutch Pressure Control, the impeller
clutch torque converter with lock-up
feature activates in second and third
gears forward and first through third
gears in reverse.
Planetary, Electronic, Power Shift
Transmission. This is the same
transmission found in the Cat 992G
Wheel Loader. Electronic shifting
provides smooth consistent shifts with
fingertip controls housed in the STIC
controller. Large diameter perimeter
clutches coupled with high contact
planetary gear sets provide high torque
carrying capacity for long trouble-free
life. Speed and direction controls are
housed in the STIC controller.
Final Drives. Are planetary consisting of a
ring gear, three planet gears or planet gear
carrier and a sun gear. Features include:
• Ring gears splined to reation hub
• Proprietary gear cutting and heat
treat methods are used in
manufacture of components
• Full-floating bronze sleeve bearings
are used on planet gears
• Oil-bath lubrication of final drive
Axle-Shaft, Oil-Disc Brakes. Are fully
hydraulic, completely sealed and never
need adjustment. Disc face grooves
provide cooling even when brakes are
applied for a long, fade resistant life.
• This design provides a larger cooling
oil reservoir and thicker separator
plates than conventional brake designs.
This gives the brake higher heat
dissipation rates giving it higher
capacity than conventional
oil-disc brakes.
• The location of the brake reduces
service time. Conventional brakes
require final drive disassembly.
The axle-shaft brake design allows
brake service while leaving the final
drive intact. Duo-cone
® seals are
between the wheel and spindle for
a tight fit. Reduced service time (oil
change interval is every 2,000 hours)
and machine downtime keeps
operating costs low.
Parking Brake. Is spring-applied, oil-
released, dry disc that are mounted on
the transmission transfer gear output shaft.
The Electronic Monitoring System alerts
the operator if the transmission is engaged
while the parking brake is applied and
also if the pressure drops and, in which
case, the brake is automatically applied.
Manual override is possible to allow
movement of the machine.
Secondary Brakes. Are fully modulated
and the front and rear service brake
circuits are isolated, allowing one circuit
to operate if pressure drops in the other.
Service Brakes. Are four wheel,
hydraulic, oil dipped, multiple disc brakes
that are adjustment-free, completely
enclosed and allow modulated
engagement without slack adjusters.
Starting System. Is direct-electric 24-volt
with a 95-amp alternator and two 12-volt,
1,300 CCA, 190-amp-hour batteries.
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