JLG 340AJ, Service And Maintenance Manual

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SECTION 3 - CHASSIS & TURNTABLE
3121259 – JLG Lift – 3-37
4. Remove end cover assembly (2) and seal ring (4). Discard
seal ring.
5. Thoroughly wash end cover (2) in proper solvent and
blow dry. Be sure the end cover valve apertures are free
of contamination. Inspect end cover for cracks and the
bolt head recesses for good bolt head sealing surfaces.
Replace end cover as necessary.
NOTE: A polished pattern (not scratches) on the cover from rota-
tion of the commutator (5) is normal. Discoloration would
indicate excess fluid temperature, thermal shock, or excess
speed and require system investigation for cause and close
inspection of end cover, commutator, manifold, and rotor
set.
6. Remove commutator ring (6). Inspect commutator ring
for cracks, or burrs.
7. Remove commutator (5) and seal ring (3) Remove seal
ring from commutator, using an air hose to blow air into
ring groove until seal ring is lifted out and discard seal
ring. Inspect commutator for cracks or burrs, wear, scor-
ing, spalling or brinelling. If any of these conditions exist,
replace commutator and commutator ring as a matched
set.