Lull 944E-42, Service Manual

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2.29 Model 644E-42/944E-42 Rev. 6/04
General Information, Specifications and Maintenance
2.10 BEARINGS
2.10.1 Bearing Removal
1. NEVER remove bearings unless absolutely
necessary! Always use the recommended puller to
reduce the risk of bearing or related component
damage.
2. When bearings or bushings are removed, verify that
the bearing or bushing is free from discoloration,
nicks, scuffing, and signs of overheating. If in doubt,
replace the bearing or bushing.
2.10.2 Bearing Cleaning
Wear safety glasses. Clean bearings acceptable for
service in a suitable solvent. NEVER spin-dry a bearing
with compressed air; this can cause metal-to-metal
contact and bearing damage. Compressed air can also
cause a bearing to come apart. After cleaning a bearing,
immerse it in clean lubricating oil until needed.
2.10.3 Bearing Installation
1. Always install bearings carefully to help avoid
damaging their delicate surfaces.
2. Install bearings using one of the following methods:
• PRESS FIT for installation on rotating parts such
as shafts and gears;
• PUSH FIT into static locations such as reduction
gear housings.
3. Always install the bearing into the rotating part first,
whenever possible.
4. Use a press or the proper installation tools when
installing a bearing or bushing.
5. In the absence of a press or proper installation tools,
carefully heat the casing and/or bearing in hot oil to
assist in the installation.
2.11 PRESSURE TESTING AND
ADJUSTMENT
Prior to pressure testing or adjustment, verify that all
hoses and tubes are in good condition and that all fittings
are tight.
Use pressure gauges with the proper ranges and ratings
to measure the specified pressures.
Use correct test procedures to help prevent personal
injury, damage to the system or test equipment.
Verify that the hydraulic oil is at proper operating
temperature, 130 - 160° F (54 - 71° C), before adjusting
the pressure reducing valve, or relief valves. If necessary,
operate the vehicle to raise the oil temperature. In the
absence of a temperature gauge, the oil temperature can
be checked by placing a hand against the side or the
bottom of the reservoir; if the tank is too hot to keep your
hand in contact with the tank, the oil temperature should
be within the proper range.