John Deere stx38 - Manual (Page 82)

3 - 50
4/23/97
REPAIR ENGINE
Specification:
Crankcase Seal Depth
. . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.0 mm (0.157 in.)
or until its top surface is flush with machined bore
opening.
IMPORTANT: Coat inside seal lip with grease to
aid installation. Install crankshaft carefully to
avoid damaging seal.
4. Carefully install crankshaft seal.
INSPECT OIL PICKUP
1. Remove cap screw (A) and plate (B) to remove
pickup screen (C).
2. Clean screen with approved solvent. Replace if
damaged.
3. Install screen, plate, and cap screw.
4. Install oil pan, see Remove and Install Oil Pan.
OIL PUMP RELIEF VALVE
INSPECT ION
1. Loosen cap screw(C) and retainer (B) to gain
access to individual components.
2. Remove and measure spring (A), replace if not to
specification.
Specification:
Relief Valve Spring Free Length
. . . . . . . . . . . . . . . . . . . . . . . . 25.1968 mm (0.992 in.)
3. Inspect spring, piston (E), and body (D). Replace
parts that are damaged or worn.
4. Install components with retainer and cap screw.
5. Install oil pan, see Remove And Install Oil Pan.
OIL PUMP INSTALLATION
1. Remove cover (E), O-ring (D), pump outer rotor (C),
and pump inner rotor (B).
2. Inspect rotor, pump, and inside surface of cavity (A)
for scoring, discoloration, and wear.
IMPORTANT: If oil leaks out between engine oil
base and tractor frame and not from the
crankshaft seal, check O-ring groove (F) for
casting flaws. If flashing is found in O-ring
groove, cover the oil pump rotors to prevent
contamination (G), use the sharpened end of a
screwdriver as a chisel or a small file to remove
flashing. Be careful not to gouge the bottom of
the O-ring groove. Remove all chips or filings
from the groove. (Recommend using a Q-Tip®).
3. Replace parts as necessary.
4. Lubricate parts (A, B, and C) with engine oil. Install
in cavity.
5. Install O-ring and cover. Tighten cap screws to
specification.
Oil Pump Cover Cap Screw Specification:
New Oil Pan (Thread Forming) . . 6.2 N•m (55 lb-in.)
Used Oil Pan (Threads Cut). . . . . 4.0 N•m (35 lb-in.)
Oil Pump Cover-to-Rotor
Clearance . . . . . . . . . . . . . . . 0.076 mm (0.003 in.)
M55872
B A
C
M52123
A
E
C
D
B
D
B
C
A
E
M55874
M85809
F
G