Manitowoc Grove RT770E, Service Maintenance Manual

Page: 311 / 357

8-35
RT770E UNDERCARRIAGE
8
Published 11/26/2014, Control # 447-05
GROVE
7. Remove OMS string potentiometer from inside outrigger
beam.
Installation
1. Install string potentiometer inside outrigger beam.
2. Install the OMS string potentiometer enough to engage
slotted hole with top mounting hardware.
3. Install the lower mounting hardware.
4. Attach the OMS string potentiometer connector to the
attaching point on the outrigger beam.
NOTE: Avoid free-release of cable to prevent damage to
the OMS string potentiometer.
5. Connect electrical harness connector to string
potentiometer.
6. Install access cover plate to outrigger box.
Jack Cylinder
Description
Four jack cylinders are used on the crane, one at the end of
each outrigger beam. The jack cylinders provide the force for
the outrigger beam’s vertical movement. The cylinder weighs
approximately 63.30 kg (139.5 lb).
Maintenance
NOTE: Refer to Cylinders , page 2-61 for Disassembly and
Assembly of the cylinders.
Removal
1. Extend the outrigger beam slightly for improved access
to the jack cylinder; shut down the engine.
2. Tag and disconnect the hydraulic hoses from the jack
cylinder. Remove the fittings from the ports. Cap or plug
all openings.
3. Remove the cylinder cap.
4. Place a jack capable of supporting the weight of the jack
cylinder at the base of the cylinder barrel. Jack up the
cylinder just enough to relieve any pressure on the
cylinder retaining pin.
5. Remove the cotter pins securing the cylinder retaining
pin and remove the cylinder retaining pin and cylinder
cap retaining bracket.
6. Jack the jack cylinder up just enough to insert the
retaining pin back into the cylinder. Insert the retaining
pin into the lugs on the cylinder and secure the pin in
place with the cotter pins.
7. Fasten a nylon strap onto the cylinder retaining pin and
use an adequate lifting device to lift the jack cylinder out
of the tube on the beam assembly.
Installation
1. Apply grease (EP-MPG) to the ID of the jack cylinder
support tube.
2. If removed, install wear ring in groove in bottom of
support tube and in groove at top on jack cylinder.
3. Place a jack beneath the cylinder tube on the outrigger
beam. Using the same method as described under
Removal, lower the jack cylinder into the cylinder tube
on the outrigger beam until the retaining pin is just above
the tube. Position the jack so that it will support the
cylinder in this position. Remove the lifting device from
the cylinder.
4. Remove the retaining pin and cotter pins from the
cylinder.
5. Lower the jack until the holes in the cylinder rod align
with the holes in the outrigger beam.
6. Apply anti-seeze compound to the retaining pin. Secure
the cylinder and cylinder cap retaining bracket to the
support tube with the retaining pin and cotter pins.
7. Install the cylinder cap.
1
7944
FIGURE 8-33
CAUTION
Use a nylon strap to remove the cylinder. This will ensure
the retaining pin is not damaged.