[1] – Check camshaft end play while camshaft is installed in cylinder block. (See Check Camshaft End
Play in Section 220, Group 15.)
[2] – Check camshaft side gap (C) with camshaft removed from cylinder block using a feeler gauge between camshaft thrust plate (A) and front side of first camshaft bearing journal (B).
If side gap is excessive, remove gear and replace thrust plate.
[3] –
Inspect gear for chipped or broken teeth. Replace if necessary.
a. Remove gear using a knife-edge puller and an arbor press. Place flat side of puller against camshaft gear.
Heat new gear to approximately 150 °C (300 °F) .
c. Install key (D) into slot of camshaft.
d. Install thrust plate (A) onto camshaft, centering onto stepped shoulder (E).
IMPORTANT:
Avoid Damage! Be sure αthat thrust plate is not trapped between camshaft gear and stepped shoulder while gear is being pressed on.
Install heated camshaft gear with longer hub of camshaft gear facing camshaft. Align slot in gear with key in shaft. Press camshaft into gear until hub of gear is tight against camshaft shoulder.
[4] –
Inspect camshaft for bend by using a pair of V-blocks and a dial indicator. Turn camshaft slowly and read variation on indicator. If variation is greater than wear limit, replace camshaft.
[5] –
Measure camshaft lobe height (F) using a micrometer. If lobe height is less than wear limit, or if there are chips or scratches in lobes or bearing journals, replace camshaft.
[6] –
Measure camshaft end journals (G) and intermediate journals (H) outside diameters. If journal
diameters are less than wear limit, replace camshaft.
[7] –
Measure front camshaft bore (I) diameter at gear housing end.
a. If inside diameter exceeds wear limit, replace engine block on 3TNM74.
b. If inside diameter exceeds wear limit, replace bushing on 3TNV76 and 3TNV80.
[8] –
Measure intermediate and flywheel end camshaft bore diameters using the following procedures:
a. Remove engine back plate. (See Remove and Install Engine Back Plate in this group.)
b. Remove plug (J) using a long wooden dowel. Insert a long wooden dowel through gear housing side and drive plug out.
c. Measure intermediate (K) and flywheel-end camshaft bore (L) diameters. If bore diameter exceeds wear limit, replace cylinder block. If bore clearance (bore ID minus camshaft journal OD) exceeds specification, replace camshaft, cylinder block or both.
d. Apply John Deere Form-In Place Gasket, or an equivalent, on outer edge of plug. Install plug until edge of plug is slightly below edge of engine block.
e. Install engine back plate.
