General Information
This procedure applies to rear gear train engines only. For front gear train engines, the preferred method of removing
the camshaft gear is to first remove the camshaft. Refer to Procedure 001-008 in Section 1.
Once the camshaft is removed, the camshaft gear can be removed. Refer to Procedure 001-013 in Section 1.
Camshaft gear removal/installation tool, Part Number 38223589, can be used to replace the camshaft gear with
the camshaft partially installed. This method should only be used in applications that prohibit the removal of the
camshaft in chassis.
Initial Check
Use gauge, Part Number 3824564, and magnetic base, Part Number 3377399, to check the camshaft end play.
See the Measure section later in this procedure.
NOTE: If the camshaft end play is out of specification check the camshaft thrust plate. Refer to Procedure
001-008 in Section 1.
Check the camshaft backlash. See the Measure section later in this procedure.
If the camshaft backlash is out of specification inspect the camshaft and crankshaft gears for obvious flaws. If a
damaged gear is not found, remove the camshaft to check the journal diameters for correct dimensions. If the engine
has been recently rebuilt, check previous repairs for correct installation and dimensions.
Remove
Rotate the engine to allow the camshaft timing marks to align. When the timing marks are aligned, cylinder 1 is at
top dead center (TDC).
NOTE: The engine can have a mark on the camshaft gear or chamfered tooth.
Service Tip: Engines equipped with air compressors may require the air compressor to be timed to the engine. To
be sure the air compressor is properly timed when the camshaft gear is later installed, scribe an alignment line on the air compressor and camshaft gear before removing the camshaft gear.
On engines equipped with an air compressor/accessory drive, it may be necessary to loosen/remove some of the
air compressor/accessory drive mounting hardware in order to remove the camshaft gear. It is not necessary to
remove the air compressor/accessory drive completely.
Loosening/removing the air compressor/accessory drive mounting hardware will give enough clearance to remove
the camshaft gear.
Loosen the air compressor mounting fasteners (1 ).
Remove the two capscrews securing the air compressor support (2).
If equipped with a hydraulic pump driven off of the air compressor, it may be necessary to remove and/or loosen
some or all of the mounting fasteners.
Remove the camshaft gear capscrews.
Remove the camshaft gear.
Clean and Inspect for Reuse
Clean the camshaft gear. Dry with compressed air.
Inspect for cracks and fretting at the capscrew holes on the camshaft and camshaft gear.
Inspect for fretting on the camshaft gear teeth.
Inspect for cracked or broken teeth on the camshaft gear.
Remove any frets, burrs, or raised metal with abrasive pad, Part Number 3823258.
If frets, burrs, or raised metal can not be removed with abrasive pad, Part Number 3823258, replace the gear.
Install
Align the camshaft gear with the pin in the camshaft and the mark on the crankshaft gear.
Install camshaft gear onto the camshaft.
Check to make sure the timing marks on the camshaft gear align with the timing marks on the crankshaft gear. If
equipped with an air compressor, make sure to align the line that was scribed on the camshaft gear and air compressor gear during the camshaft gear removal step.
If this was not done, reference the air compressor timing procedures. Refer to Procedure 012-014 in Section 12.
NOTE: The engine can have a mark on the crankshaft gear or chamfered tooth.
Install camshaft gear capscrews and tighten.
Torque Value: 36 Nโขm [ 27 ft-lb ]
Tighten the compressor/accessory drive mounting fasteners. Refer to Procedure 012-014 in Section 12.
If equipped with a hydraulic pump driven off of the air compressor, install and/or tighten any of the mounting
fasteners. Refer to the OEM service manual.
Measure
Use gauge, Part Number 3824564, and magnetic base, Part Number 3377399, to check the camshaft end play.
NOTE: If the camshaft end play is out of specification, check the camshaft thrust plate. Refer to Procedure
001-008 in Section 1.
