Caterpillar D8K
Maintenance schedule, common problems & OEM parts breakdown
The Caterpillar D8K is a large track-type tractor (bulldozer) built from 1974 to 1982 as Caterpillar's upgrade to the D8H, and it was the last conventional-drive machine in the D8 line. It runs a turbocharged, aftercooled Cat D342T inline-six diesel rated at 300 flywheel horsepower (224 kW) net at 1330 rpm, up from the D8H's roughly 275 hp. Operating weight with a blade fitted runs 31,430 to 32,523 kg (69,300 to 71,700 lb) depending on blade type and transmission choice; a bare shipping tractor without blade or canopy weighs less, around 24,270 to 25,580 kg (53,500 to 56,400 lb). Caterpillar offered the D8K as a direct-drive machine (76V series, U.S.-built) and as a powershift machine with a torque converter (77V series built in the U.S., 66V series built in the U.K.), fitted with straight or angling blades and rear ripper attachments. Caterpillar replaced the D8K in 1982 with the D8L, the first D8 with the elevated-sprocket Hi-Drive undercarriage.
Compared with the D8H, the D8K added pilot-operated hydraulic implement controls, sealed-and-lubricated track chains, a pinned equalizer bar, and combined steering-and-braking control, along with a reworked operator's station offered with a heated, air-conditioned ROPS cab. The power increase to 300 hp made the D342T a more highly stressed engine, and it became known for cylinder liner movement and counterbore cracking in the block; Caterpillar partly corrected this partway through the production run with a lower-deck, spacer-plate block. In the used and parts market today, the D8K holds value as a fully mechanical machine with no electronics to diagnose, simple field repair, and lower rebuild cost than the D8N, D8R, or D8T that followed it; buyers weigh direct-drive versus powershift configuration, undercarriage wear, and engine liner history when pricing a unit.
Below: full specifications, fluids & capacities, the factory service schedule, common service parts, verified fault codes, what owners discuss, attachment guidance, the complete assembly directory, and a serial-number reference. Complete parts lists with full OEM part numbers, exploded diagrams, quantities, and fitment data are available free in Heavy Parts AI.
Caterpillar D8K specifications
Engine
| Engine model | Caterpillar D342 diesel, turbocharged, four-stroke-cycle |
| Bore x stroke | 146 mm x 203 mm (5.75 in x 8.0 in) |
| Displacement | 20.4 L (1,246 cu in) |
| Flywheel power | 224 kW (300 hp) at 1330 rpm, SAE standard ambient conditions; full rated power maintained to 2,300 m (7,500 ft) altitude |
| Fuel system | Individual, adjustment-free injection pumps with precombustion-chamber, non-clogging injectors; turbocharged for improved combustion at altitude |
| Starting/electrical | 24V direct electric start, in-seat switch; 35-amp alternator standard, 50-amp alternator optional |
| Emissions | Pre-emissions-era mechanical diesel (production era mid-1970s to early 1980s); no EPA/Tier off-road emissions certification applies to this engine |
| Series/production note | Turbocharged D342 rated 224 kW (300 hp) is the engine used across the D8K production run per factory literature reviewed; no mid-run engine change documented. D8K followed the D8H (lower-rated D342) and was superseded by the D8L (higher-rated, larger, elevated-sprocket design) — do not blend specs across those nameplates. |
Weights
| Operating weight, power shift, S-blade (standard) | 31,980 kg (70,500 lb) — with lubricants, coolant, full fuel, hydraulic controls, ROPS canopy and operator |
| Operating weight, direct drive, S-blade | 31,430 kg (69,300 lb), same equipped basis as above |
| Operating weight, power shift, U-blade | 32,523 kg (71,700 lb) |
| Operating weight, power shift, A-blade (straight) | 31,661 kg (69,800 lb) |
| Shipping weight, power shift (bare tractor, no blade/canopy) | 24,810 kg (54,700 lb) — with lubricants, coolant, 10% fuel |
| Shipping weight, direct drive (bare tractor, no blade/canopy) | 24,270 kg (53,500 lb) |
| Shipping weight with ROPS canopy, power shift | 25,580 kg (56,400 lb) |
| Shipping weight with ROPS canopy, direct drive | 25,040 kg (55,200 lb) |
| Weight variance note | Operating weight shifts with blade choice, transmission option (power shift vs. direct drive), cab vs. canopy, and any ripper fitted; treat published figures as configuration-specific, not a single fixed weight |
Dimensions
| Length without blade | 5.26 m (17 ft 3 in) |
| Length with S-blade | 6.58 m (21 ft 7 in) |
| Width over standard tracks | 2.79 m (9 ft 2 in) |
| Track gauge (centerline to centerline) | 2.13 m (84 in / 7 ft 0 in) |
| Height to top of ROPS canopy | 3.40 m (11 ft 2 in) |
| Ground clearance (per SAE J894, from ground face of shoe) | 0.43 m (17.1 in) |
| Drawbar height (from ground face of shoe) | 0.53 m (21 in) |
| Track length on ground | 3.15 m (124 in / 10.3 ft) |
| Standard track shoe width | 560 mm (22 in); optional wider shoes of 610 mm, 660 mm and 710 mm (24, 26, 28 in) offered in standard and extreme-service versions |
| Undercarriage design | Sealed-and-lubricated track with a reinforced, multi-roller track-frame; lifetime-lubricated rollers and idlers; oscillating front idler travel of 399 mm (15.7 in); split master link and hydraulic track adjusters standard; sprocket rim segments bolt on for field re-rimming |
| Ground contact area (standard shoes) | 3.51 m² (5,437 sq in) |
| Attachment length add-ons (from base tractor length of 5.26 m / 17 ft 3 in) | Single-shank ripper +2.01 m (6 ft 7 in); multishank ripper +1.52 m (5 ft 0 in); S-blade +1.32 m (4 ft 4 in); U-blade +1.65 m (5 ft 5 in); A-blade +1.35 m (4 ft 5 in); A-blade angled 25° +2.26 m (7 ft 5 in); C-frame only +0.81 m (2 ft 8 in) |
Performance
| Power shift transmission, 1st gear | 0-4.0 km/h forward (0-2.5 mph); 0-5.0 km/h reverse (0-3.1 mph) |
| Power shift transmission, 2nd gear | 0-7.1 km/h forward (0-4.4 mph); 0-8.7 km/h reverse (0-5.4 mph) |
| Power shift transmission, 3rd gear (top) | 0-10.9 km/h forward (0-6.8 mph); 0-13.5 km/h reverse (0-8.4 mph) |
| Direct-drive transmission (optional), forward speeds, gears 1-6 | 2.7, 3.5, 4.8, 6.3, 8.2, 11.3 km/h (1.7, 2.2, 3.0, 3.9, 5.1, 7.0 mph) |
| Direct-drive transmission, reverse speeds, gears 1-6 | 2.7, 3.5, 4.8, 6.4, 8.2, 11.4 km/h (1.7, 2.2, 3.0, 4.0, 5.1, 7.1 mph) |
| Direct-drive drawbar pull at rated engine rpm, gears 1-6 | 25,400 / 18,930 / 12,990 / 9,370 / 6,610 / 4,090 kgf (56,000 / 41,740 / 28,640 / 20,650 / 14,580 / 9,010 lb) |
| Direct-drive maximum drawbar pull at lug, gears 1-6 | 32,540 / 24,420 / 16,955 / 12,400 / 8,945 / 5,770 kgf (71,730 / 53,830 / 37,380 / 27,340 / 19,720 / 12,730 lb) |
| Power shift drawbar pull | Published in factory literature as a drawbar-pull-versus-ground-speed curve rather than discrete per-gear figures; pull peaks near 1st-gear engagement and tapers as speed rises. Usable pull always depends on traction and equipped weight of the tractor. |
| Ground pressure | 88.3 kPa (12.8 psi) with standard 560 mm (22 in) shoes, S-blade, power-shift transmission, full operating trim. Figure shifts with blade choice, optional wider shoes, or an added ripper — treat as configuration-specific. |
| Gradeability | Not published as a discrete percentage figure in factory literature for this model; drawbar-pull-versus-speed curves stand in for a stated maximum-grade rating |
Blades
| S-blade (straight, standard) | Width 4.04 m (13 ft 3 in) over cupped end bits, 102 mm (4 in) narrower over standard forged end bits; height 1.52 m (5 ft 0 in); digging depth 510 mm (20 in); ground clearance 1.40 m (4 ft 7 in); maximum tilt 1.02 m (40 in); blade weight 5,480 kg (12,080 lb) with tilt cylinder, excluding hydraulic control valving |
| U-blade (universal) | Width 4.24 m (13 ft 11 in); height 1.52 m (5 ft 0 in); digging depth 510 mm (20 in); ground clearance 1.40 m (4 ft 7 in); maximum tilt 1.06 m (41.7 in); blade weight 6,040 kg (13,310 lb) with tilt cylinder, excluding hydraulic control valving |
| A-blade, straight (angling dozer) | Width 4.72 m (15 ft 6 in) over end bits; C-frame only (no moldboard) measures 3.48 m (11 ft 5 in); height 1.12 m (3 ft 8 in); digging depth 610 mm (24.2 in); ground clearance 1.32 m (4 ft 4 in); maximum tilt 330 mm (13 in); blade weight 5,260 kg (11,590 lb), excluding hydraulic control valving |
| A-blade, angled 25 degrees | Width 4.27 m (14 ft 0 in); height 1.12 m (3 ft 8 in); digging depth 790 mm (31 in); ground clearance 1.57 m (5 ft 2 in); maximum tilt 330 mm (13 in) |
| Blade capacity | Heaped/SAE blade capacity in cubic meters or cubic yards is not stated in the factory spec sheet reviewed for this model; only physical width, height, digging-depth and tilt figures are published |
| Cutting edges and control | Bolt-on cutting edges and end bits; push-arm braces connect through a sliding center ball that absorbs side loading on the arms and blade; blade raise/lower/tilt run off a common hydraulic control lever on hydraulically controlled blades |
Service capacities
| Fuel tank | 640 L (170 US gal) |
| Cooling system | 121 L (32 US gal) |
| Engine crankcase (oil) | 32.9 L (8.7 US gal) |
| Power-shift transmission, bevel gear and steering-clutch compartments (includes torque converter) | 117 L (31 US gal) |
| Direct-drive transmission, flywheel clutch, steering clutch and bevel gear compartments | 132 L (35 US gal) |
| Final drive, each side | 36.0 L (9.5 US gal) |
| Hydraulic system reservoir (blade/tilt/ripper pilot hydraulics, fender-mounted tank) | 70 L (18.5 US gal) |
Values vary by configuration, region, and serial range — confirm against your machine before planning transport or lifts.
D8K fluids & capacities
| System | Capacity | Recommended fluid |
|---|---|---|
| Engine crankcase (w/ filter) — D342T turbocharged inline-6 diesel (turbocharged-aftercooled from later serial run) | approx. 34.8 US qt (32.9 L); single-sourced figure, confirm against your unit's serial-specific OMM before ordering oil | Diesel engine oil graded to the era's API CD/CC-class multigrade; SAE 30 for warm ambient, stepping down to SAE 10W or 10W-30 in cold weather per Cat's temperature-viscosity chart. Modern cross-reference: Cat DEO-family diesel engine oil. |
| Cooling system | Not reliably documented in available secondary sources — published figures for this row conflict with the hydraulic tank number and should not be trusted without the serial-specific OMM | Cat-spec ethylene-glycol based antifreeze/coolant (or Cat corrosion-inhibitor water mix where extreme cold protection isn't required), per the era's Cat cooling system specification. |
| Fuel tank | approx. 169-170 US gal (640-644 L) | No. 2-D diesel fuel; No. 1-D diesel fuel recommended below freezing ambient per Cat's cold-weather fuel guidance. |
| Transmission (3F/3R powershift) | approx. 124 US qt (117.4 L) on powershift-equipped units; direct-drive-transmission units reported around 140 US qt (132.5 L) — varies by transmission configuration, treat both as single-sourced pending OMM confirmation | SAE-graded powertrain/gear oil per Cat's temperature chart (SAE 30 typical operating range, SAE 10W in cold start conditions). Modern cross-reference: Cat TDTO-family transmission/drive-train oil. |
| Bevel gear / steering clutch compartment | Not separately documented — this compartment draws from the same oil supply as the powershift transmission case on this platform, with no distinct fill volume published | Same oil spec as the transmission (SAE-graded gear/powertrain oil per temperature; Cat TDTO-family equivalent). |
| Final drives (each side) | Not confirmed in available sources for this model — consult the serial-specific OMM or your Cat dealer for the exact per-side fill volume | SAE-graded gear oil from the same powertrain-oil family used in the transmission/bevel gear case (Cat TDTO-family equivalent), per Cat's temperature-viscosity guidance. |
| Hydraulic system / tank | approx. 18.5 US gal (70 L) as reported by parts/spec aggregators — this number recurs against more than one field in low-quality secondary sources, so treat as unconfirmed until checked against the OMM | Cat-spec hydraulic oil (SAE 10W-class hydraulic oil in the era's viscosity chart, cross-referencing to modern Cat TDTO/HYDO-family fluid). |
| Pivot shaft / equalizer bar and other grease fittings | N/A — grease-gun lubrication points, no fill volume | Cat multipurpose grease, NLGI 2 (or NLGI 1/0 in cold climates per the temperature-graded grease chart), applied at scheduled grease intervals. |
Capacities are refill values from factory literature — always fill to the dipstick/sight gauge, not the number.
Caterpillar D8K maintenance schedule
| Service interval | Tasks |
|---|---|
| Every 10 h |
|
| Every 250 h |
|
| Every 500 h |
|
| Every 1,000 h |
|
| Every 2,000 h |
|
| Every 6,000 h |
|
Servicing the D8K beyond the schedule
Predictive Maintenance & Fluid Analysis
Run scheduled oil sampling on the D342T sump. This turbocharged, aftercooled six is prone to cylinder liner movement in the block, and early wear or coolant-in-oil readings flag counterbore or liner-seal trouble before it drops a liner. Test coolant additive level at every service interval; wet liners on this engine pit and crack from cavitation if additive drops off. Sample transmission oil separately on 77V/66V powershift units versus 76V direct-drive final drives, since wear metals differ by drivetrain.
Corrective & Common Repairs
The D342T's best-known failure is a dropped cylinder liner. Counterbore cracking or liner sink lets compression push into the cooling system and coolant out the overflow. Machines without the factory spacer-plate block retrofit are most exposed; inspect liner protrusion at every top-end job. On 76V direct-drive units, steering clutch and brake linkage wear out of adjustment and need regular resetting. On 77V/66V powershift units, expect eventual torque converter and clutch-pack wear as the common overhaul driver instead.
Overhaul & Rebuild Points
Undercarriage is the D8K's biggest rebuild line item. It uses conventional, non-elevated rollers and sprockets, which take more direct shock and dirt loading than the later Hi-Drive D8L design, so chain, roller, and idler wear accelerates faster under heavy dozing or ripping. Engine overhauls center on the D342T's liner and counterbore condition. Powertrain rebuilds split by configuration: torque converter and clutch packs on powershift 77V/66V machines, steering clutch and brake assemblies on direct-drive 76V machines. Plan parts sourcing accordingly.
Seasonal & Environment Servicing
Cold climates need a reliable ether starting aid for the 24V electric-start D342T and full-strength antifreeze protection; a weak coolant additive mix invites liner cavitation on top of normal freeze risk. In hot, dusty conditions shorten air cleaner and aftercooler core cleaning intervals, since a clogged core cuts the turbocharged engine's aftercooling and derates power. The D342T holds full rated output up to roughly 2,300 m (7,500 ft) altitude; above that, expect the factory-rated derate and flag it during pre-shift checks in mountain or high-plateau operation.
D8K common service parts
| Part number | Part | Notes | |
|---|---|---|---|
| 2S-8877 | Filter As-Engine Oil | Lubrication service | Check fitment → |
Always confirm against your machine's serial number — cross-check any part in Heavy Parts AI before ordering.
D8K fault codes & troubleshooting
| Code | Meaning | Likely cause | What to do |
|---|---|---|---|
| Coolant Temperature Gauge – Red Zone (High) | Engine coolant temperature has risen into the gauge's red operating zone. | Blocked or fouled radiator core, low coolant level, worn or slipping fan drive, or sustained high-load work in hot ambient conditions. | Reduce load and let temperature drop before shutdown; once cooled, check coolant level, clean radiator fins, and inspect the fan belt and drive. |
| Engine Oil Pressure Gauge – Red Zone (Low) | Engine lubricating oil pressure has dropped below the normal band shown on the analog gauge. | Low oil level, oil diluted by fuel or hydraulic oil, worn oil pump, or worn crankshaft/camshaft bearings on a high-hour engine. | Shut down without delay, check oil level and condition, and confirm the gauge itself reads correctly before further teardown. |
| Torque Converter Oil Temperature Gauge – Red Zone (High) | Torque converter and transmission oil temperature has exceeded the safe operating range. | Sustained stall-condition or high-load operation, low transmission oil level, a plugged torque-converter oil cooler, or a worn converter. | Ease off the load and shift toward neutral or a lower gear to let the converter cool, then check oil level and inspect the cooler for restriction. |
| Charging System Indicator (Ammeter/Voltmeter) – Discharge | Alternator output is not keeping pace with electrical load; the panel gauge shows discharge instead of charge. | Worn or slipping drive belt, a failing alternator or regulator, or a loose/corroded wiring connection. | Check belt tension and condition, inspect wiring and grounds, and test alternator output. |
| Air Cleaner Service Indicator – Restriction (Red Signal) | Intake air restriction across the air cleaner element has reached the service limit shown on the indicator. | A dirty or clogged primary air filter element, or a damaged intake hose or seal causing a false restriction reading. | Service or replace the filter element as indicated, then reset the indicator after cleaning. |
| Transmission/Torque Converter Oil Filter Bypass Indicator – Extended | The oil filter bypass valve has opened, shown by a pop-up (extended) indicator button on the filter housing. | Cold, thickened oil at startup, or a clogged filter element restricting flow enough to force the bypass open. | Recheck after the machine reaches operating temperature; if the button stays extended once warm, change the filter element. |
Codes and remedies are general guidance for this model family — always confirm with diagnostic tooling and your dealer before major repairs.
D8K attachments & work tools
Blades
Factory blade options for the D8K are the 8S straight blade (4040 mm / 13'3" wide, 1520 mm high, 1020 mm max tilt), the 8U U-blade (4240 mm / 13'11" wide, 1520 mm high, 1060 mm max tilt), and the 8A 25-degree angling blade (4720 mm / 15'6" wide, 1120 mm high, 330 mm max tilt). All three run off a single hydraulic lever that controls lift, tilt, and angle together. VPAT (variable pitch/angle tilt) is not documented for this generation — that feature belongs to later D6-family dozers. A semi-U (SU) low-ground-pressure blade is cataloged for the later D8N/D8R/D8T line, not for the D8K itself.
Rippers
Two ripper packages are documented for the D8K: a positionable single-shank hydraulic ripper (paired with the S-blade/closed-cab package) and a multi-shank parallelogram ripper from the No. 8 series (paired with the U-blade/closed-cab package). The multi-shank unit lets the shank pattern be adjusted for ground conditions, from a single shank up to a fuller multi-shank spread, trading penetration depth for total ripped width. Published attachment weights are not consistent across sources for this exact model — expect a heavy multi-tonne class typical of D8-size rippers, and confirm the figure for your specific shank configuration with a dealer.
Winches
The factory winch pairing for the D8K is the Cat 58, run from a single lever covering reel-in, reel-out, inching, and braking, with roughly a 292 mm (11.5 in) drum diameter and about a 1:32 gear ratio; it's the winch tied to the open-ROPS/A-blade package. Reported bare-drum line pull for this class of winch runs roughly 45,000 kg (about 99,000 lb), with heavier aftermarket dozer-class winches sized for the D8-D9-D10 range pulling upward of 112,000 lb (51 t) bare drum. Treat pull figures as configuration-dependent and verify against the winch's own data plate.
Drawbars/counterweights
A rigid rear drawbar is the standard rear towing point on the D8K. A rear counterweight is offered as a bolt-on ballast option, normally fitted in place of a rear ripper or winch to keep rear track loading and traction balanced when the machine runs blade-only or with a heavy front attachment. Counterweight and rear-mounted implements (ripper, winch) occupy the same rear-frame location, so they're mutually exclusive on one machine.
Cab/ROPS guarding
The D8K was offered with either an open ROPS canopy or a closed ROPS/FOPS cab, with the closed cab forming the base for forestry and pipeline conversions. Forestry and waste-handling builds commonly add heavy screen guarding over the glass, a screened rear window, belly/underside guarding, and radiator screening; rear screening is specifically called for when a rear winch is fitted, to shield the operator from the cable and rear pinch points. These heavier guarding packages are typically aftermarket ROPS/cab conversion kits layered onto the base machine rather than a distinct factory Caterpillar forestry trim for this generation.
Hydraulic arrangement (front/rear tools)
Blade lift, tilt, and angle run off one hydraulic lever feeding the implement pump, which is driven off the turbocharged D342 engine alongside the power-shift transmission. The ripper (single- or multi-shank) has its own separate lift/tilt hydraulic lever, independent of the blade circuit. The winch is a separate clutched unit at the rear of the power train with its own control lever, not tied into the blade or ripper hydraulic circuits — front and rear tools are operated independently of one another.
All D8K assemblies by section
Every catalogued assembly group for the Caterpillar D8K. Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.
Central Structure
6n1860 Cylinder Block Cover Group
| 6N***60 | Cover Group-Cylinder Block; Cylinder Block Cover Group | 1 |
4n6929 Cylinder Block Group
| 4N***29 | Cylinder Block Assembly | 1 |
2p903 Cylinder Block Assembly
| 2P***03 | Cylinder Block Assembly | 1 |
6n5400 Cylinder Block Assembly
| 6N***00 | Cylinder Block Assembly | 1 |
7n3035 Cylinder Block Assembly--Replaced By 8n4312 Shown On Page 18e
| 7N***35 | Cylinder Block Assembly | 1 |
8n4312 Cylinder Block Assembly
| 8N***12 | Cylinder Block Assembly | 1 |
6n5401 Cylinder Block Group
| 6N***01 | Cylinder Block Assembly | 1 |
2p903 Cylinder Block Group
| 2P***03 | Cylinder Block Assembly | 1 |
6n1859 Cylinder Block Group
| 6N***59 | Cylinder Block Group; Cylinder Block Group | 1 |
4n9873 Cylinder Block Group
| 4N***73 | Cylinder Block Group | 1 |
7n3803 Cylinder Block Group--Field Installation
| 1A***69 | Bolt (R.H. Side Flywheel Housing) | 12 |
| 1D***99 | Bolt Plate To Head | 26 |
| 1D***00 | Bolt (.625" Dia.-7.50" Long) | 2 |
4h9649 Camshaft Group
| 4H***49 | Camshaft Group | 1 |
4s6868 Connecting Rod And Piston--6 Required
| 4S***68 | Connecting Rod And Piston | 1 |
4n6816 Connecting Rod And Piston Group--6 Required
| 4N***16 | Connecting Rod And Piston Group | 1 |
Crankshaft Bearing Replacement
| 6N***38 | Bearing Intermediate | 6 |
| 6N***39 | Bearing Center | 1 |
4n5236 Crankshaft Group
| 4N***36 | Crankshaft Group; End-To L.H. Rod Assembly | 1 |
7n142 Crankshaft Seal Group--Front
| 7N***42 | Crankshaft Seal Group | 1 |
| 9J***10 | Sleeve | 1 |
| 9N***39 | Seal | 1 |
4n9875 Cylinder Block Cover Group
| 4N***75 | Cylinder Block Cover Group | 1 |
4s9388 Crankshaft Bearing Replacement Groups
| 4S***88 | For Use With .025 Undersize Crankshaft | 1 |
| 4S***96 | Bearing Assembly Intermediate | 6 |
| 4S***97 | Bearing Assembly Center | 1 |
4s9389 Crankshaft Bearing Replacement Groups
| 4S***89 | For Use With .050 Undersize Crankshaft | 1 |
| 4S***98 | Variable Timing Drive Assembly; Bearing Assembly Intermediate | 6 |
| 4S***99 | Bearing Assembly Center | 1 |
4s9387 Crankshaft Bearing Replacement Groups
| 4S***87 | For Use With Standard Crankshaft | 1 |
Cooling System
6n334 Transmission Oil Cooler Group
| 6N***34 | Cooler Group-Transmission Oil; Transmission Oil Cooler Group | 1 |
6n2676 Oil Cooler Group
| 6N***76 | Engine Oil Cooler Group; Oil Cooler Group | 1 |
6n335 Transmission Oil Cooler Group
| 6N***35 | Transmission Oil Cooler Group | 1 |
6n337 Water Lines Group--Part 2 Of 2
| 6N***37 | Water Lines Group | 1 |
6n337 Water Lines Group--Part 1 Of 2
| 6N***37 | Water Lines Group | 1 |
6n338 Water Lines Group--Part 1 Of 2
| 6N***38 | Water Lines Group | 1 |
6n338 Water Lines Group--Part 2 Of 2
| 6N***38 | Water Lines Group | 1 |
5s1911 Water Pump Group (4s7757 N/S)--Type 2
| 5S***11 | Water Pump | 1 |
5s1911 Water Pump Group (4s7757 N/S)--Type 1
| 5S***11 | Water Pump | 1 |
6n6015 Water Pump Group
| 6N***15 | Water Pump Group | 1 |
Electrical System
2p1204 Alternator Group
| 2P***04 | Alternator Group | 1 |
4n5233 Alternator Group
| 4N***33 | Alternator Group-Charging; Alternator Group | 1 |
3s4463 Electric Starting Motor Group--24 Volt
| 3S***63 | Electric Starting Motor Group; Electric Starting Motor Group--24 Volt | 1 |
3s5160 Glow Plug And Wiring Group
| 3S***60 | Glow Plug And Wiring Group; Glow Plug Group | 1 |
1p9182 Electric Starting Motor Group--Part 2 Of 2
| 1P***82 | Starting Motor Group | 1 |
1p9182 Electric Starting Motor Group--Part 1 Of 2
| 1P***82 | Starting Motor Group | 1 |
6n5123 Solenoid Switch Assembly--24 Volt
| 6N***23 | Switch As-Solenoid | 1 |
Engine Arrangement
4n4445 Basic Engine Arrangement--Part 2 Of 2
| 2P***10 | Service Meter Group | 1 |
| 2P***50 | Governor And Fuel Injection Pump Group | 1 |
| 2P***60 | Fuel Injection Lines Group | 1 |
4n4445 Basic Engine Arrangment--Part 1 Of 2
| 2P***38 | Breather And Oil Filler Group; Breather And Filler Group | 1 |
| 2P***03 | Oil Filter Group | 1 |
| 3H***93 | Oil Pump Group | 1 |
4n4444 Basic Engine Arrangement--Part 2 Of 2
| 2P***50 | Governor And Fuel Injection Pump Group | 1 |
| 2P***60 | Fuel Injection Lines Group | 1 |
| 2P***44 | Fuel Filter Group | 1 |
4n7664 Basic Engine Arrangement--Part 1 Of 2
| 1M***26 | Power Take-Off Group; Power Take-Off Group | 1 |
| 2P***43 | Filler & Breather Group; Breather And Filler Group | 1 |
| 2P***52 | Gauge Group-Oil Level (Dipstick); Oil Level Gauge Group | 1 |
4n7664 Basic Engine Arrangement--Part 2 Of 2
| 2P***13 | Service Meter Group; Service Meter Group | 1 |
| 2P***50 | Governor And Fuel Injection Pump Group | 1 |
| 2P***36 | Control Group-Governor; Governor Control Group | 1 |
4n4444 Basic Engine Arrangement--Part 1 Of 2
| 2P***38 | Breather And Oil Filler Group; Breather And Filler Group | 1 |
| 2P***03 | Oil Filter Group | 1 |
| 3H***93 | Oil Pump Group | 1 |
Front Structure
6n941 Fan Drive Group
| 6N***41 | Fan Drive Group | 1 |
4n5235 Pulley And Damper Group
| 4N***35 | Pulley And Damper Group | 1 |
5h4204 Water Pump Idler Gear Group
| 5H***04 | Water Pump Idler Gear Group | 1 |
Fuel System And Governor
2p2436 Governor Control Group
| 2P***36 | Control Group-Governor; Governor Control Group | 1 |
2p1213 Service Meter Group
| 2P***13 | Service Meter Group; Service Meter Group | 1 |
2p6509 Service Meter Group
| 2P***09 | Service Meter Group | 1 |
2p1210 Service Meter Group
| 2P***10 | Service Meter Group | 1 |
2p5171 Governor And Fuel Pump Drive Group
| 2P***71 | Accessory Drive Group; Governor & Fuel Injection Pump Group | 1 |
4n7536 Air Lines Group
| 4N***36 | Air Lines Group | 1 |
8n9527 Fuel Heater Changeover Group--Field Installation
| 8N***27 | Changeover Group | 1 |
2p5144 Fuel Filter Group
| 2P***44 | Fuel Filter Group | 1 |
2p2660 Fuel Injection Lines Group
| 2P***60 | Fuel Injection Lines Group | 1 |
1p9988 Fuel Pump Housing Group
| 1P***88 | Fuel Injection Pump Group | 1 |
1p2297 Fuel Priming Pump Assembly
| 1P***97 | Fuel Priming Pump Assembly | 1 |
6n9740 Fuel Priming Pump Barrel Assembly
| 6N***40 | Fuel Priming Pump Barrel Assembly | 1 |
2p5208 Fuel Priming Pump Group
| 2P***08 | Fuel Priming Pump Group | 1 |
8s5095 Fuel Ratio Control Group
| 8S***95 | Fuel Ratio Control Group | 1 |
4n4880 Fuel Transfer Pump Group (2p5194 N/S)
| 4N***80 | Fuel Transfer Pump Group | 1 |
4n4733 Governor Control Group
| 4N***33 | Governor And Decelerator Control Group | 1 |
4n4732 Governor Control Group--Part 2 Of 2
| 4N***32 | Governor And Decelerator Control Group; Governor Control Group | 1 |
4n4732 Governor Control Group--Part 1 Of 2
| 4N***32 | Governor And Decelerator Control Group; Governor Control Group | 1 |
2p1650 Governor And Fuel Injection Pump Group
| 2P***50 | Governor And Fuel Injection Pump Group | 1 |
2p1499 Governor Group--Part 1 Of 2
| 2P***99 | Governor Group | 1 |
2p1499 Governor Group--Part 2 Of 2
| 2P***99 | Governor Group | 1 |
8s7608 Primary Fuel Filter Group
| 8S***08 | Primary Fuel Filter Group | 1 |
6n4402 Torque Control Group
| 6N***02 | Torque Control Group | 1 |
Intake And Exhaust System
6n171 Exhaust Manifold Group
| 6N***71 | Exhaust Manifold Group | 1 |
6n170 Inlet Manifold Group
| 6N***70 | Inlet Manifold Group | 1 |
6n7203 Turbocharger Group (3s2341 N/S)
| 6N***03 | Turbocharger Group | 1 |
6n3253 Turbocharger Group (3s2341 N/S)
| 6N***53 | Turbocharger Group | 1 |
Lower Structure
2p6552 Oil Level Gauge Group
| 2P***52 | Gauge Group-Oil Level (Dipstick); Oil Level Gauge Group | 1 |
4n3291 Oil Level Gauge Group
| 4N***91 | Oil Level Gauge Group | 1 |
Lubrication System
2p2743 Breather And Filler Group
| 2P***43 | Filler & Breather Group; Breather And Filler Group | 1 |
2s8877 Oil Filter Assembly
| 2S***77 | Filter As-Engine Oil | 1 |
6n1861 Oil Filter Group
| 6N***61 | Filter Group-Oil; Oil Filter Group | 1 |
6n1862 Oil Lines Group--Part 2 Of 3
| 6N***62 | Lines Group-Oil; Oil Lines Group | 1 |
6n1862 Oil Lines Group--Part 1 Of 3
| 6N***62 | Lines Group-Oil; Oil Lines Group | 1 |
6n1862 Oil Lines Group--Part 3 Of 3
| 6N***62 | Lines Group-Oil; Oil Lines Group | 1 |
2p2538 Breather And Filler Group
| 2P***38 | Breather And Oil Filler Group; Breather And Filler Group | 1 |
2p5103 Oil Filter Group
| 2P***03 | Oil Filter Group | 1 |
6n336 Oil Lines Group--Part 2 Of 3
| 6N***36 | Oil Lines Group | 1 |
6n336 Oil Lines Group--Part 3 Of 3
| 6N***36 | Oil Lines Group | 1 |
6n336 Oil Lines Group--Part 1 Of 3
| 6N***36 | Oil Lines Group | 1 |
4n9877 Oil Pan Group
| 4N***77 | Oil Pan Group | 1 |
6n2412 Oil Pump Drive Group
| 6N***12 | Oil Pump Drive Group | 1 |
1p9340 Oil Pump Group (3h3093 N/S)
| 1P***40 | Oil Pump Group | 1 |
6n2463 Oil Pump Group
| 6N***63 | Oil Pump Group | 1 |
Rear Structure
1m626 Power Take-Off Group--Part 2 Of 2
| 1M***26 | Power Take-Off Group; Power Take-Off Group | 1 |
1m626 Power Take-Off Group--Part 1 Of 2
| 1M***26 | Power Take-Off Group; Power Take-Off Group | 1 |
4s7368 Support Group
| 4S***68 | Support Group-Engine; Support Group | 1 |
4n5703 Support Group
| 4N***03 | Engine Support Group | 1 |
4s7417 Flywheel Group
| 4S***17 | Flywheel Group; Flywheel Group | 1 |
9s1807 Flywheel Group
| 9S***07 | Flywheel Group | 1 |
4n9874 Flywheel Housing Group
| 4N***74 | Flywheel Housing Group | 1 |
3s1660 Power Take-Off Group
| 3S***60 | Power Take-Off Group-Rear; Power Take-Off Group | 1 |
9h6248 Power Take-Off Drive Group
| 9H***48 | Rear Power Take-Off Drive Group; Power Take-Off Drive Group | 1 |
Service Equipment And Supplies
Gasket Kits
Upper Structure
8n6004 Cylinder Head Service Group--Field Installation
| 8N***04 | Cyl Head A | 1 |
7n3503 Cylinder Head Assembly--Replaced By 8n6000 Shown On Page 22c
| 7N***03 | Cylinder Head Assembly | 1 |
8n6000 Cylinder Head Assembly
| 8N***00 | Cylinder Head Assembly | 1 |
4n9894 Cylinder Head Group
| 4N***94 | Cylinder Head Group | 1 |
4n9878 Front Housing Cover Group
| 4N***78 | Front Housing Cover Group | 1 |
4n9876 Front Housing Group
| 4N***76 | Front Housing Group | 1 |
4n9893 Valve Mechanism Cover Group
| 4N***93 | Valve Mechanism Cover Group | 1 |
4n9892 Valve Mechanism Group
| 4N***92 | Valve Mechanism Group | 1 |
D8K serial number reference
The PIN/serial plate on a D8K-era Cat dozer is riveted to the left front of the mainframe, and the number is also stamped into the frame itself as a backup if the plate is lost or painted over. Read the first three characters as the prefix, which ties the machine to its model and the plant that built it; the digits after that are the sequential build number within that prefix run. Since the D8K predates Cat's later 17-character PIN format, a dealer confirms exact build year and factory configuration by looking up the prefix plus serial number against factory build records.
| Prefix | Identifies | Notes |
|---|---|---|
| 66V | D8K, UK-built, powershift transmission | UK-built, mechanically the same as the US-built 77V aside from plant and PIN. Turbocharged D342T six-cylinder engine, rated near 224 kW (300 hp) gross. Produced from 1974 into the early 1980s, before the D8L replaced the model in 1982. |
| 76V | D8K, US-built, direct-drive transmission | US-built with direct-drive transmission (no torque converter/powershift). Same turbocharged D342T engine as the other D8K prefixes. Lower-volume configuration next to the powershift 77V. Produced 1974 through the end of the D8K run around 1982. |
| 77V | D8K, US-built, powershift transmission | US-built with powershift transmission; the highest-volume D8K prefix and the most common configuration seen. Turbocharged D342T engine, about 224 kW (300 hp) gross. Produced 1974-1982, when the D8L (3408 engine) took over the nameplate. |
Frequently asked questions
What engine does the Caterpillar D8K use?
A turbocharged, aftercooled Cat D342T inline-six diesel, 20.4 L (1,246 cu in) displacement, rated at 300 flywheel horsepower (224 kW) net at 1330 rpm. That is up from the roughly 275 hp of the D8H it replaced.
What is the operating weight of the Caterpillar D8K?
With a blade fitted, 31,430 to 32,523 kg (69,300 to 71,700 lb) depending on blade type and transmission choice. A bare shipping tractor without blade or canopy weighs less, around 24,270 to 25,580 kg (53,500 to 56,400 lb).
What replaced the Caterpillar D8K?
Caterpillar replaced the D8K in 1982 with the D8L, the first D8 to use the elevated-sprocket Hi-Drive undercarriage. The D8L was followed by the D8N, D8R, and the current D8T.
What D8K owners discuss
What engine powers the D8K, and how much does it make?
Direct drive or power shift — which does the community prefer, and how do you tell them apart?
Why do so many D8K owners complain about the machine running hot?
What wears out first in the undercarriage?
What do owners say about adjusting the steering clutches and brakes?
What electrical issues come up most on a D8K?
What should you check before buying a used D8K?
Compiled from owner and technician discussions across the industry — experiences vary by serial range and machine history.
Need a specific D8K part?
Search live OEM part data, check fitment, and cross-reference alternatives with Heavy Parts AI.