Remove and install camshaft, Inspect camshaft, Repair – John Deere stx38 User Manual

Page 69

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4/23/97

3 - 37

ENGINE

REPAIR

REMOVE AND INSTALL CAMSHAFT

1. Rotate crankshaft to align two sets of marks (A).
2. Remove camshaft (B).
3. Inspect camshaft closely, replace as necessary.
4. Coat entire camshaft with engine oil.
5. Install camshaft with four timing marks (A) aligned.
6. Check camshaft end play.
7. If not within specification, use appropriate shims

from Camshaft Shim Kit (D), shown below in photo
M58327.

8. Align flat surface of balancer shaft with bore flat of

oil pump inner rotor gear as you install oil pan.

9. Install push rods, rocker arm assembly, and valve

cover, see those procedures earlier in this section.

Specification:

Camshaft End Play

. . . . . . . . . . . . . 0.076–0.127 mm (0.003–0.005 in.)

INSPECT CAMSHAFT

1. Inspect camshaft for worn or broken teeth.
2. Measure journals (A). Replace camshaft if

measurements do not meet specifications.

Camshaft Journal Specification:

O.D. (New)

. . . . . . . . 19.96219.975 mm (0.7859—0.7864 in.)

O.D. (Max. Wear Limit) . . . . . 19.959 mm (0.7858 in.)

3. Inspect lobes (B). Replace camshaft if lobes show

excessive wear.

4. Inspect ACR mechanism (C). Replace spring if

necessary and check that weight moves freely.

5. Measure camshaft bore (E) in oil pan.
6. Subtract journal OD. from bore ID. to determine

clearance with camshaft journal. Replace if not
within specifications.

Camshaft Bearing Bore Specification:

Oil Pan Camshaft Bore
(New) . . . . . 20.000—20.025 mm (0.7874—0.7844 in.)
(Max. Wear Limit) . . . . . . . . . 20.038 mm (0.7889 in.)
Camshaft to Bore
Clearance . . . 0.025—0.063 mm (0.0010—0.0025 in.)

7. Measure camshaft bore (F) in crankcase.
8. Subtract journal OD. from bore ID. to determine

clearance with camshaft journal. Replace if not
within specification.

Camshaft Bearing Bore Specification:

Crankcase Camshaft Bore
(New) . . . . . 20.000—20.025 mm (0.7874—0.7844 in.)
(Max. Wear Limit) . . . . . . . . . 20.038 mm (0.7889 in.)

Camshaft to Bore

Clearance . . . 0.025—0.063 mm (0.0010—0.0025 in.)

B

A

M55873

A

B

C

A

A

D

M58327

Plastic Gear

Steel Gear

Camshaft

Camshaft

M52091

E

M52092

F

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