John Deere Series 300 Diesel Engine Workshop Manual, 1995 (P/N CTM8)

This John Deere Component Technical Manual (P/N CTM8), dated February 23, 1995, covers Series 300 diesel engine models 3029, 4039, 4045, 6059, and 6068. It supersedes the November 4, 1992 edition. The 3029 coverage is for engines built in Saran, France. Coverage for the other listed models includes Dubuque- and Saran-built engines.

Searchable PDF with Chapter Bookmarks

Text search and illustrations. The manual has searchable text and bookmarks for chapters, index entries, and page numbers. Labels are readable in the fuel-system diagram and injection-pump cutaways. Four illustration panels in the lubrication and cooling sections are blank.

The ZIP contains one printable English-language PDF with 505 pages. The total includes the cover, spine sheet, foreword, two pages of edition and coverage notes, and eight pages with only running headers and footers.

Engine Rebuild, Injection Service, and Diagnostic Tests

These are selected procedures and references. The manual also covers break-in oil and supplemental coolant additives.

• Engine teardown and assembly. Covers lifting and repair-stand mounting, wet cylinder liners, pistons, connecting rods, crankshaft and main bearings, flywheel installation, and rear oil seals.
• Cylinder head and valves. Covers head inspection, valve guides and seats, and valve clearance checks and adjustment with the engine cold.
• Timing gears and auxiliary drives. Covers crankshaft- and camshaft-driven auxiliary gears, balancer shaft timing, and front PTO configurations.
• Lubrication and cooling. Covers standard- and high-flow oil coolers, standard- and high-capacity oil pumps, thermostat and water manifold service, and water pump repair.
• Turbocharger and aftercooler. Covers turbocharger inspection, center housing and rotating assembly replacement, and aftercooler removal, inspection, and leak testing.
• Fuel injection service. Covers Stanadyne DB2, DB4, and DM4 and Lucas CAV pump removal, installation, and timing, plus aneroid service, injector nozzle testing and repair, and fuel-system bleeding.
• Engine testing and break-in. Covers compression, oil pressure, crankcase blow-by, cooling system pressure, intake restriction checks, boost, and fuel supply pressure, along with dynamometer testing and post-overhaul break-in.

John Deere wrote this manual for experienced technicians and identifies the special tools required for specific service work.

Matching the Engine to the Machine

The engine identification section explains the factory, aspiration, user, and application codes. Cross-reference charts connect engine builds to tractors, combines, cotton pickers and strippers, self-propelled sprayers, windrowers, loaders, crawlers, excavators, motor graders, forestry equipment, forklifts, and OEM installations.

Use the corresponding machine technical manual for access and engine removal or installation. The machine manual also identifies which components can be serviced with the engine in place.

Build Differences During Reassembly

The procedures distinguish aluminum and composite timing covers, early and later front plates and camshaft bushings, and two-piece and unitized rear oil seals. Oversize balancer shaft bushings are specified for 4039 engines with one-piece shafts. The 4045 design with bolt-on balancer weights uses a different service approach.

Reference tables give torque and torque-angle values, piston and bearing clearances, crankshaft inspection and grinding limits, and gear backlash and end play. The crankshaft chapter includes a flywheel housing face runout check. Reassembly charts identify where to apply sealant and threadlocker.

Tool references include the JDG739 camshaft bushing service set, JD254 gear timing tool, JDE81-4 timing pin, and KJD10164 front crankshaft seal installer. Fabrication drawings cover the DFRG2 injection pump timing mark transfer tool and DFRG3 cylinder liner holding fixture.

Lubrication, Cooling, and Turbocharger Service

The Common Lube comparison shows where the regulator and bypass valves differ from those on earlier 4045 and 6068 blocks. Block identification matters when selecting the valves and springs. Damaged or blocked piston cooling orifices can harm the piston, pin, bushing, and liner. An omitted orifice can cause low or no oil pressure.

Water pump procedures distinguish low-flow, standard-duty high-flow, modular, and heavy-duty high-flow pumps. A separate cap screw protrusion check addresses service-pump interference and coolant leaks on specified Saran OEM builds.

The rollover-stand instructions explain how oil can reach the intake, exhaust, and cylinders through a connected turbocharger oil line and cause hydraulic lock at restart. A turbocharger cutaway shows the oil path through the center housing.

Injection Pump Variants and Fault Diagnosis

The DB2 procedures distinguish retained and non-retained drive shafts. Static timing instructions are supplemented by dynamic timing with the JT07158 TIME TRAC kit and pump-specific speed and governor checks. The Stanadyne and Lucas CAV cutaways show how the pumps operate. John Deere directs internal injection pump repair and bench testing to an authorized diesel injection repair station.

The engine sectional view and head gasket joint illustrations show how the liners, head, and gasket seal together. The fault charts connect symptoms such as coolant in the oil or bubbles in the radiator to possible leak paths and follow-up checks. The tune-up section includes basic battery and starter checks and refers charging-circuit diagnosis to CTM77.

Liner Standout and Compression Test Examples

For the Series 300 wet liners, the manual specifies a liner height of 0.030–0.100 mm (0.0010–0.0040 in.) above the block when checked with the liners secured.

The engine compression test specifies a minimum of 2,400 kPa (350 psi) and a maximum cylinder-to-cylinder difference of 350 kPa (50 psi). The figures are referenced to 600 ft above sea level. The test section gives an altitude correction and specifies a minimum hot cranking speed of 200 rpm.