Textron Jacobsen Super LF 1880 Fairway Mower with ROPS, Service & Repair Instructions

Page: 104 / 300

HYDRAULICS
8D-14
Swashblock Group
See Figure 8D-7 for swashblock group disassembly.
Figure 8D-7. Swashblock Group Disassembly
INSPECTION
• Clean all parts thoroughly.
• Discard all seals and o-rings and replace with new
ones.
• Check all locating pins for damage.
• Check all springs for cracks or distortion, replace if
necessary.
• Check the fit of the control pin in swashblock, there
should be no play.
• Inspect the valve plate surface that mates with
cylinder barrel for excessive wear or scoring. Minor
defects can be removed by lightly stoning the
surface to within 0.0001” (0.03 mm). Excessive
stoning will remove the hardened surface. If worn or
damaged excessively, replace valve plate and
cylinder barrel.
• Inspect the hydrodynamic cylinder rotating group.
Inspect the cylinder bearing and barrel, replace if
worn or damaged.
• Piston shoes must pivot smoothly, end play should
not exceed 0.003” (0.076 mm). To check end play
proceed as follows:
1. Place square end of piston on a bench and hold
firmly.
2. Pull on the end of the hose with the other hand
and note the end play. A good piston/shoe fit will
have no end play with the shoe free to rotate and
pivot on the piston ball.
• Check each shoe for proper thickness (See
Figure 8D-8). All shoes must be equal within 0.001”
(0.025 mm). The shoes should be replaced as a set.
• Inspect swashblock for wear, scoring or damage.
Replace if worn or damaged.
Figure 8D-8. Piston and Shoe Thickness
• Compare saddle-bearing thickness in the wear area.
If difference in thickness is greater than 0.010”
(0.25 mm) replace saddle bearings.
• Inspect mating surface of swashblock for cracks or
excessive wear. Swashblock should move freely
and smoothly.
• Examine the seal area of the drive shaft for scoring
or roughness.
• Inspect the front shaft bearing for roughness,
galling, or binding, replace if necessary.
• Check shaft and splines for wear and straightness,
replace if necessary.
• Check the faces of the gerotor pump assembly and
the matching faces of the valve plate and rear plate
for scratches or damage. Remove minor defects by
stoning or lapping the surface. Only stone or lap
gerotor pump surfaces. If wear is excessive replace
as necessary.
Swashblock
Saddle
Bearings
Main Case
End play must not exceed
0.0003" (0.076 mm) when
new, or 0.006" (0.152 mm)
when worn.
All shoe faces must
be free of nicks.
All shoes must be equal
within 0.0001" (0.025 mm)
at this dimension.