Caterpillar D7H
Maintenance schedule, common problems & OEM parts breakdown
The Caterpillar D7H is a medium-class track-type tractor (crawler dozer) built roughly 1986 to 1996. It runs a Cat 3306 turbocharged diesel, a 10.5-liter engine rated at about 231 hp (172 kW) gross / 215 hp (160 kW) net on the original D7H, with the Series II update (1991 onward) raising net output to roughly 230 hp (172 kW). Operating weight runs from about 23-24 t (50,000-53,300 lb) in Standard trim up to around 25.9 t (57,000 lb) for the LGP (Low Ground Pressure) version, with an XR extended-track option and a WDA waste-handling chassis also offered; blade choices span Straight, Semi-Universal, and Universal moldboards. Drive goes through a 3-speed forward/3-speed reverse planetary powershift transmission. The D7H replaced the D7G/D7G2, which used direct-drive transmissions with cable/lever-operated steering clutches, and was itself replaced by the D7R in 1996, which added electronic engine control.
The D7H was the first D7 to use Caterpillar's elevated-sprocket (high-drive) undercarriage, moving the final drives up off the ground and letting the track roller frame pivot on its own trunnion shaft, independent of the drive train. That extra chain joint means pin and bushing wear can add up faster than on an older low-drive Cat unless the machine has the factory sealed-and-lubricated track option. The Series II update (1991 onward) added differential steering as an option alongside the original clutch-and-brake steering, and raised net engine output. Because the 3306 is a mechanically governed engine with no electronic control module, the D7H remains popular with owner-operators and land-clearing outfits who want a simple, field-serviceable machine. Undercarriage, ripper, and winch components carry over across the D7 high-drive lineage, which keeps parts support strong long after factory production ended.
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 D7H specifications
Identification / Production
| Model | Caterpillar D7H track-type tractor (crawler dozer), including the mid-production Series II update |
| Production span | Approximately 1985 to the mid-1990s; the D7H was the first D7 built with Caterpillar's elevated (high) drive-sprocket undercarriage, replacing the flat-track D7G |
| Succession | Replaced by the D7R in the mid-1990s |
| Configurations documented | Standard (S-track), LGP (low ground pressure), XR (extended-length track), and WDA (waste-handling arrangement) chassis variants |
Engine
| Engine model | Cat 3306, turbocharged inline 6-cylinder diesel |
| Displacement | 10.5 L (640.8 cu in) |
| Gross power, standard D7H (pre-Series II) | 172 kW (231 hp) at 2,100 rpm |
| Net power, standard D7H (pre-Series II) | 160 kW (215 hp) |
| Gross power, D7H Series II | 184 kW (247 hp); some spec listings instead show 160 kW (215 hp) for Series II — treat as varying by source/market tune |
| Net power, D7H Series II | 172 kW (230 hp) |
| Emissions certification | Pre-emissions-tier era mechanical diesel; no EPA/EU tier rating published for this model |
| Electrical system | 24V, alternator charging (35-50A depending on listing), 12V batteries |
Weights
| Operating weight, standard D7H (S dozer, standard track) | 22.9-23.8 t (50,400-52,100 lb) depending on blade/track fitment and source |
| Operating weight, D7H Series II standard | 24.2 t (53,341 lb) |
| Operating weight, D7H Series II LGP | 25.9 t (57,069 lb) |
| Operating weight, D7H WDA Series II (waste-handling arrangement) | 24.9 t (55,001 lb) |
| Base/shipping weight, bare Series II tractor | 20.0 t (44,154 lb) before blade and attachments |
| Upper operating-weight range, fully equipped | Up to about 27.2 t (60,047 lb) with LGP tracks plus attachments such as a rear ripper |
Dimensions
| Overall length with blade, standard configs | 5.54-5.59 m (18.18-18.30 ft) depending on series/blade |
| Overall length without blade | 4.62-4.63 m (15.16-15.20 ft) |
| Width over tracks, standard shoe | 2.54 m (8.34 ft) |
| Width over tracks, LGP shoe | 3.15 m (10.34 ft) |
| Height to cab/ROPS top | 3.34-3.43 m (10.95-11.23 ft) depending on series and cab type |
| Ground clearance | 0.40-0.41 m (1.33-1.34 ft) |
| Track gauge, standard | 1.98 m (6.5 ft) |
| Track gauge, LGP | 2.23 m (7.32 ft) |
| Track length on ground, standard Series II | 2.90 m (9.52 ft) |
| Track length on ground, LGP | 3.18 m (10.41 ft) |
| Track length on ground, XR (extended) variant | 3.07 m (120.8 in), same shoe width as standard but a longer ground-contact footprint for reduced pressure without going to full LGP width |
| Ground contact area, standard D7H (20 in shoe) | 2.94 m2 (4,560 in2) |
| Ground contact area, standard Series II (22 in shoe) | 3.24 m2 (5,022 in2) |
| Ground contact area, LGP (36 in shoe) | 5.83 m2 (9,037 in2) |
| Track shoe width options, standard line | 508-660 mm (20-26 in) grouser shoes offered across the standard chassis |
| Track shoe width, LGP | 914 mm (36 in) |
Performance
| Transmission | Planetary powershift, 3 speeds forward and 3 speeds reverse; steering via multi-disc clutches and brakes |
| Maximum travel speed, forward | 11.9 km/h (7.4 mph), consistent across standard, LGP and WDA configurations |
| Maximum travel speed, reverse | 14.3 km/h (8.9 mph) |
| Per-gear speed breakdown | Not published on available spec sheets for this model — only the top forward and reverse speeds are documented |
| Drawbar pull | Not consistently published as a single spec-sheet figure for this model. Performance-handbook data places first-gear pull near 145-150 kN (32,500-34,000 lbf) at stall, tapering to roughly 60-65 kN (13,500-14,500 lbf) around 2.4 km/h (1.5 mph); actual pull depends heavily on ground traction and conditions |
| Ground pressure, standard D7H (pre-Series II) | 76-77 kPa (11.0-11.1 psi) |
| Ground pressure, Series II standard | 73 kPa (10.6 psi) |
| Ground pressure, Series II LGP | 43-44 kPa (6.3-6.4 psi) |
| Gradeability | Not published as a standalone percentage figure for this model; effective grade climbing is governed by drawbar pull and track traction rather than a stated maximum grade |
| Hydraulic relief valve pressure | 22,750 kPa (3,300 psi) |
| Hydraulic pump flow | About 175 L/min (46.2-46.3 US gal/min) |
Blades
| Standard blade, pre-Series II D7H | Width 3.84 m (12.6 ft), height 1.28 m (50.3 in), capacity 4.5 m3 (5.9 cu yd), maximum cutting depth 500 mm (19.7 in) |
| Standard blade, D7H Series II | Width 3.90 m (12.8 ft), height 1.36 m (53.6 in), capacity 5.2 m3 (6.8 cu yd), maximum cutting depth 528 mm (20.8 in) |
| LGP blade, D7H Series II | Width 4.51 m (14.8 ft), height 1.34 m (52.8 in), capacity 6.0 m3 (7.8 cu yd), maximum cutting depth 668 mm (26.3 in) |
| WDA (waste-handling) blade, D7H Series II | Width 3.81 m (12.5 ft), a notably tall high-lift refuse-pack face at 1.88 m (74.1 in), capacity 9.7 m3 (12.7 cu yd), maximum cutting depth 528 mm (20.8 in) |
| Blade naming convention | Cat literature for this model groups blades by chassis arrangement (standard, LGP, WDA) rather than by the S/SU/U/A letter codes used on some other dozer families; no VPAT blade option is documented for the D7H — VPAT arrived on later-generation models |
Service Capacities
| Fuel tank | 488 L (129 US gal) is the figure most consistently reported; a small number of listings show about 480 L (126 US gal) |
| Hydraulic system | Reported figures vary by listing: roughly 52-66 L (13.8-17.5 US gal) on some Series II listings versus about 115 L (30.4 US gal) on pre-Series II listings. This spread likely reflects different measurement bases (implement tank only versus total hydraulic system) — confirm against the spec sheet for your specific machine |
| Cooling system | About 52.6 L (13.9 US gal), same 3306 engine used across the model run |
| Engine oil (crankcase, refill with filter change) | Approximately 15.9 L (4.2 US gal), based on 3306 engine service data — verify against the sump configuration on your specific unit |
| Final drive, each side | About 9.6-9.8 L (2.6 US gal) |
Values vary by configuration, region, and serial range — confirm against your machine before planning transport or lifts.
D7H fluids & capacities
| System | Capacity | Recommended fluid |
|---|---|---|
| Engine crankcase (with filter) — Cat 3306 turbocharged diesel | Approx. 27.3 L (28.8 US qt / 7.2 US gal). | Cat DEO (Diesel Engine Oil) to the performance level current for this era. SAE 10W-30 is the preferred year-round grade between about -18°C and 40°C (0°F to 104°F). Drop to a lighter multigrade (SAE 0W-20 or 0W-30) for regular starts below -18°C (0°F); a straight SAE 30 or 15W-40 is suited to sustained hot climates above about 10°C (50°F). Use the highest viscosity that still allows reliable cold starting. |
| Cooling system | Approx. 52 L (13.8-13.9 US gal / 54.4 US qt) — two independent spec sheets converge on this figure (51.5-52.6 L). | Cat DEAC (Diesel Engine Antifreeze/Coolant), a glycol-based heavy-duty coolant with organic/inorganic corrosion inhibitors, giving freeze protection to about -37°C (-34°F) at full strength. Dose with Cat SCA (Supplemental Coolant Additive) at scheduled intervals to control pitting, cavitation erosion, and mineral scale; top up SCA rather than replacing coolant at every service unless contamination is found. |
| Fuel tank | 488 L (129 US gal) — consistent across every spec sheet checked. | No. 2-D diesel fuel per the applicable ASTM/EN diesel fuel spec. Switch to a winter-blend or kerosene-cut fuel (or an approved cold-flow additive) when ambient temperatures approach the fuel's cloud point, to prevent wax gelling and filter plugging. |
| Transmission, bevel gear and steering clutch (combined power-train compartment) | Approx. 121 L (128 US qt) — one source reports this as a single combined figure shared by both the 6-speed direct-drive and 3-speed powershift transmission options. Some Cat crawler-tractor OMMs of this era split transmission from the bevel-gear/steering-clutch case into separate compartments; a separate per-compartment split was not found in available sources — confirm against the serial-specific OMM if an exact split is needed. | Factory-era spec called for a SAE 10W engine oil meeting API CD, per Cat's TO-2 transmission/drive-train oil designation (current at the time this model was built). The direct modern equivalent is Cat TDTO (Transmission/Drive Train Oil) meeting the Cat TO-4 specification. By ambient temperature: SAE 10W below about -20°C (-4°F), SAE 30 for the general -20°C to 35°C (-4°F to 95°F) range (typical factory-fill grade), and SAE 50 above about 10°C (50°F) in hot climates. Do not substitute a hydraulic-only oil (e.g. a multipurpose tractor oil) — it lacks the friction-modifier package this wet-clutch compartment needs. |
| Final drives (each side) | Approx. 9.6-9.8 L (2.6 US gal) per the spec sheets checked; sources are not explicit on whether this figure is per side or a combined total — confirm against the serial-specific OMM. | Same drive-train oil as the transmission/bevel-gear compartment — oil meeting the Cat TO-2/TO-4 specification (Cat TDTO). SAE 30 general-purpose grade, dropping to SAE 10W in sustained cold below about -20°C (-4°F) and rising to SAE 50 in sustained heat above about 35°C (95°F). |
| Hydraulic system / tank | Reported figures vary by source: most spec sheets for the base D7H converge near 115 L (30.4 US gal) for the full hydraulic system; some Series II listings instead show 52-66 L (13.8-17.5 US gal), which may reflect a tank-only measurement or a configuration difference rather than the same total-system figure. Treat as varying by configuration/series and verify against the specific machine's OMM. | Oil meeting the Cat TO-4 specification (Cat TDTO) was the factory-era hydraulic fill on this class of machine; a general multipurpose tractor oil is sometimes cited as an original alternative but does not meet the TO-4 friction-material requirement and should not be substituted where TO-4 fluid is called for. Viscosity by climate follows the same pattern as the power-train compartment: SAE 10W cold, SAE 30 moderate, SAE 50 in sustained heat. |
| Pivot shaft (track-roller-frame recoil-spring / pivot-shaft bearing) | Not a scheduled-drain fluid — the pivot shaft carries a small internal oil reservoir that lubricates the bearing; no separate refill volume is published in available sources. | Oil meeting the Cat TO-4 specification (Cat TDTO), SAE 30 for general use, SAE 10W in cold climates below about -20°C (-4°F) and SAE 50 in sustained heat above about 35°C (95°F) — the same drive-train oil family used elsewhere in the power train. |
| Grease points (chassis pins, linkage, C-frame, blade lift/tilt cylinder pins, steering-clutch linkage) | Not applicable — serviced per grease fitting, not a fluid fill volume. | Cat Multipurpose Grease, NLGI 2 for the normal ambient range (roughly -20°C to 40°C / -4°F to 104°F); switch to a softer NLGI 1 or NLGI 0 grease in sustained sub-zero cold so it will still feed through a grease gun. This model's elevated-sprocket undercarriage commonly uses sealed-and-lubricated track link pins that are factory-filled for life and do not take a periodic grease point — verify undercarriage type against the specific serial number before assuming track pins need greasing. |
Capacities are refill values from factory literature — always fill to the dipstick/sight gauge, not the number.
Caterpillar D7H maintenance schedule
| Service interval | Tasks |
|---|---|
| Every 10 h |
|
| Every 250 h |
|
| Every 500 h |
|
| Every 1,000 h |
|
| Every 2,000 h |
|
| Every 4,000 h |
|
| Every 6,000 h |
|
Servicing the D7H beyond the schedule
Predictive Maintenance & Fluid Analysis
The D7H's Cat 3306 runs on mechanical gauges and warning lamps, not an electronic control module, so scheduled oil sampling on the engine, transmission, and final drives is the main way to catch wear early. Watch coolant condition: the water-to-air aftercooler core scales with mineral deposits over time and cuts power before any gauge reacts. Treat the transmission oil filter bypass indicator and air-restriction flag as leading wear signals, and confirm any dash warning against a shop gauge before condemning a part, since sender faults are common on this generation.
Corrective & Common Repairs
Transmission running hot is the most common D7H complaint: a worn torque converter dumps oil into the converter housing instead of routing it through the cooler, so temperature climbs even with a clean cooler and correct fluid level. Check the cooler pressure drop at the test ports rather than trusting the dash gauge alone. Slow or drifting blade lift traces to hydraulic pump wear, a relief valve out of setting, worn cylinder seals, or a sticking control-valve spool. Isolate cylinder versus valve-bank leakage before replacing parts.
Overhaul & Rebuild Points
This is an elevated-sprocket dozer, so pin and bushing wear at the extra chain joint adds up faster than on a low-drive Cat; pull and reverse sprocket segments once chain wear is well advanced rather than run it to failure, since a full chain-and-segment rebuild done late costs more than early segment work. On the engine, plan an inframe overhaul once injector wear or front crank seal, water pump, and precombustion-chamber-seat seepage move past ordinary wear. Steering clutch/brake or differential-steering valve rebuilds are the other major D7H overhaul items.
Seasonal & Environment Servicing
Cold starts on the 3306 need the correct coolant antifreeze concentration plus a lighter multigrade oil below about -18°C (0°F); drain fuel-tank condensation more often through temperature swings and switch to a winter-blend fuel before the cloud point hits. In hot climates, step up to a heavier oil grade and clean the aftercooler and radiator core more often to protect against scale-related power loss. On LGP or wet-ground work, check track-joint seals for abrasive intrusion, and inspect sealed-and-lubricated track pins where fitted rather than assuming they need greasing.
D7H common service parts
| Part number | Part | Notes | |
|---|---|---|---|
| 1D-4540 | Bolt,Machine Fuel Filter Mounting | Fuel system service | Check fitment → |
| 8M-3182 | Spring,Helical,Comp Engine Oil Filter Assembly | Lubrication service | Check fitment → |
| 1H-5514 | Bolt,Machine Engine Oil Filter Assembly | Lubrication service | Check fitment → |
| 2P-2537 | Stud Engine Oil Filter | Lubrication service | Check fitment → |
| 8T-6765 | Plug-Pipe | Scheduled service item | Check fitment → |
Always confirm against your machine's serial number — cross-check any part in Heavy Parts AI before ordering.
D7H attachments & work tools
Blades
The D7H (elevated-sprocket chassis, introduced 1986) is offered with Straight (S), Semi-Universal (SU) and full Universal (U) dozer blades, plus a wider angling blade on the LGP swamp configuration. Standard-blade width runs about 3.84-3.90 m (12.6-12.8 ft), height 1.28-1.36 m (50-54 in), capacity 4.5-5.2 m3 (5.9-6.8 yd3) and cutting depth roughly 500-530 mm (19.7-20.8 in); figures vary between base D7H and D7H Series II documentation, so treat as a range. The LGP angling blade runs close to 4.54 m (about 14.9 ft) front width for wide-track, low-ground-pressure work. VPAT (Variable Pitch Angle Tilt) was launched on the smaller high-drive D4H/D5H dozers and is not documented as a D7H factory blade option; angle and tilt on the D7H are handled through conventional fixed-angle or power-angle/single-tilt hydraulic mounts instead.
Rippers
Rear ripper choices for this class split into a single-shank ripper, suited to hard-packed, frozen or rocky ground plus root and obstacle removal, and a multi-shank parallelogram ripper (2-3 tooth) for faster, shallower work in thinner hard or frozen material. A multi-shank parallelogram ripper of this class weighs on the order of 3400 kg (about 7,500 lb) and uses two lift cylinders; individual replacement shanks run roughly 176 kg (388 lb) each. Ripper shanks and the parallelogram ripper frame are shared across the D7 high-drive/medium-dozer lineage that includes the D7H, so aftermarket shank stock is commonly cross-listed rather than unique to one generation.
Winches
A dedicated towing winch is available for the D7H high-drive chassis, historically built by Allied/Hyster specifically for this frame (the same winch size/class also fits the later D7R). It falls in the size/class-8 dozer-winch bracket, with class-typical line pull around 350-360 kN (roughly 80,000 lbf); exact rated pull can vary by drum/cable configuration. The winch mounts at the rear of the tractor in the same location used by the ripper or drawbar/counterweight, so only one of those three can be fitted at a time.
Drawbars/counterweights
Machines built without a ripper use a rigid drawbar built into the rear striker-bar/frame casting, with a storage compartment behind large access doors. That same rear frame is counterweight-ready, so a bolt-on counterweight can be added when extra rear ballast is wanted for backing on slopes, straight dozing stability, or towing duty, provided no winch or ripper occupies the rear mount.
Cab/ROPS guarding for forestry/waste configs
Documentation naming a specific D7H forestry or waste package is thin; general Cat medium-dozer practice for this size class and era covers a ROPS/FOPS canopy or enclosed cab with screened or heavy-duty glazing, underbody/belly guards, and rear striker-bar protection over the undercarriage. Later Cat waste-handling dozers in the same size bracket add impact-resistant polycarbonate cab glazing, engine/radiator debris screens with an auto-reversing cooling fan, and elevated light guards; treat this as a description of the class rather than a confirmed D7H factory option list, and verify exact forestry or waste guarding availability for a given D7H serial range with your dealer.
Hydraulic arrangement (front/rear tools)
Front blade functions (lift, angle, and tilt where fitted) draw from the main implement hydraulic circuit; S/SU blades are commonly mounted with fixed angling and a single tilt cylinder, while U blades use the same basic circuit scaled for the larger moldboard. D7H Series II documentation lists implement relief pressure near 22,750 kPa (3,300 psi) and pump flow near 175 L/min (46 gal/min), though this can vary by series and options. Rear tool hydraulics (ripper lift and shank-angle cylinders) run off the same pump and valve bank as the blade circuit, and since the winch, ripper and drawbar/counterweight all share one rear mounting position, only one rear hydraulic tool circuit is active on a given machine at a time.
All D7H assemblies by section
Every catalogued assembly group for the Caterpillar D7H. Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.
Basic Engine
9n-5760 Damper Gp
| 1W***78 | Spring; (35.7mm Long) | 2 |
| 1W***79 | Spring; (54.6mm Long) | 2 |
| 4B***73 | Screw-Machine; (10-24x0.5-In) | 2 |
284-7811 Kit-Hardware
| 0L***43 | Bolt 63.5 mm (3/8" X 2 1/2" -Cover Assembly To Fender | 1 |
| 0S***91 | Screw,Cap,Hexagon Bearing Retainer; Part Of Kit P/N 1w***82 | 2 |
| 0S***94 | Bolt (1 In. Long 3/8 In. Dia.); Plate Assembly To Support Assembly | 2 |
284-7810 Kit-Hardware
| 03***19 | Bolt; --To Bearing Ret. At Lower Front Shaft Bore | 4 |
| 03***57 | Bolt; --To Reverse Shaft Bearing Retainer & Forward Shaft Bearing Retainer | 4 |
| 0L***43 | Bolt 63.5 mm (3/8" X 2 1/2" -Cover Assembly To Fender | 1 |
Engine Arrangement
284-3286 Conversion Ar-Engine
| 0R***14 | Rod As-Connecting | 1 |
| 0R***43 | Cylinder Pack Group | 6 |
| 0R***91 | Nozzle As-Fuel Valve | 6 |
281-3220 Conversion Ar-Engine
| 0R***14 | Rod As-Connecting | 1 |
| 0R***43 | Cylinder Pack Group | 6 |
| 0R***91 | Nozzle As-Fuel Valve | 6 |
281-3219 Conversion Ar-Engine
| 0R***14 | Rod As-Connecting | 1 |
| 0R***43 | Cylinder Pack Group | 6 |
| 0R***91 | Nozzle As-Fuel Valve | 6 |
Fuel System
7c-8993 Fastener Gp-Fuel Inj Pump
| 0S***14 | Bolt (.25" Diameter-.50" Long) | 3 |
| 2S***83 | Bolt (3.25" Long-Drilled Head) | 1 |
| 4F***57 | Screw,Cap,Hexagon H Shock Mount To Bracket | 8 |
1w-8668 Torque Control Gp
| 1P***52 | Insulator,Bushing Governor | 1 |
| 1W***68 | Torque Control Group | 1 |
| 2P***85 | Spacer (.635 mm Thk); (0.635-mm Thk) | 1 |
111-5162 Control Gp-Fuel Ratio
| 10***93 | Washer | 1 |
| 11***62 | Control Group-Fuel Ratio (Basic) | 1 |
| 11***58 | Washer; (12.7x6.65x0.79-mm Thk) | 1 |
2w-2410 Governor Gp
| 03***16 | Bolt-Self Locking; (1/4unc X 3/4) | 3 |
| 0S***16 | Screw,Cap,Hexagon H Receptacle Mtg; Bolt Brackets To Firewall Assembly | 6 |
| 13***07 | Seal-Lip Type; (6.39mm) | 1 |
111-3769 Pump Gp-Fuel Injection
| 0S***15 | Bolt 19 mm (.75 In.) Long Return Air Console To Enclosed Rops | 4 |
| 11***69 | Pump Group-Fuel Injection | 1 |
| 11***70 | Camshaft Group | 1 |
4p-9827 Pump Gp-Fuel Injection
| 1W***87 | Valve As-Check; (Fuel Injection Pump) | 1 |
| 4P***27 | Pump Group-Fuel Injection | 1 |
| 4P***30 | Plunger & Barrel Assem. | 1 |
7c-8992 Seal Gp-Pump
| 03***79 | Seal-O-Ring (Id=10.82mm) | 1 |
| 14***77 | Gasket | 1 |
| 15***26 | Gasket | 1 |
Service Equipment And Supplies
281-3222 Kit-Engine Parts
| 10***24 | Bonnet | 1 |
| 10***37 | Bracket Assem. | 1 |
| 10***33 | Tube As-Control | 1 |
281-3221 Kit-Engine Parts
| 12***94 | Bolt-Tamperproof; (28.58mm) | 1 |
| 12***96 | Bolt-Tamperproof; (95.25mm) | 1 |
| 28***21 | Kit-Engine Parts | 1 |
284-3297 Kit-Engine Parts
| 10***24 | Bonnet | 1 |
| 10***37 | Bracket Assem. | 1 |
| 10***33 | Tube As-Control | 1 |
D7H serial number reference
The PIN plate on a D7H is mounted on the main frame/ROPS structure, typically near the operator's left foot area or on the front frame rail; clean off grease, paint, or rust to read the stamped characters. The full PIN reads as a 3-character prefix followed by a sequential unit number (for example, a block starting at unit 4000 on the 5BF prefix) - the prefix identifies the model and production block, and the trailing digits mark that unit's position within the run for that block.
| Prefix | Identifies | Notes |
|---|---|---|
| 2RG | D7H track-type tractor | Early production block, unit 1 and up. 3306 diesel. Std/XL/LGP configuration and steering system for this block are not documented in available listings - confirm with dealer. |
| 2SB | D7H track-type tractor | Parts-book break covers roughly the first 4000 units of this block. 3306 diesel. Configuration and steering system not documented in available listings - confirm with dealer. |
| 3XG | D7H track-type tractor | Service manual break starts at unit 1 of this block. Referenced across independent manual listings, but configuration (Std/XL/LGP), steering system, and generation are not stated - confirm with dealer. |
| 4AB | D7H and D7H LGP, Power Shift transmission | Block starts at unit 1. Built with Power Shift transmission and the 3306 diesel engine. Steering system for this block not separately confirmed. |
| 4FG | D7H and D7H LGP, Series II, Differential Steering | Block starts around unit 4000. Factory parts documentation groups this block with 5BF in the same Series II Differential Steering parts book, covering the D7H and D7H LGP configurations together rather than one config alone. 3306 diesel. A dated field unit places part of this block in production around 1995. Which units in this block are Std vs LGP is not separately documented - confirm with dealer. |
| 5BF | D7H and D7H LGP, Series II, Differential Steering | Operator and parts manuals start at unit 1, with a later parts-book break around unit 4000. Grouped with 4FG in the same factory Series II Differential Steering parts book, covering D7H and D7H LGP together. 3306 diesel. |
| 5WB | D7H, clutch-steer / steering-brake configuration | Confirm with dealer - referenced only in a single field service discussion covering clutch-steer and steering-brake repair; generation and exact build option not otherwise corroborated. |
| 77Z | D7H track-type tractor | Confirm with dealer - grouped with the 79Z and 80Z blocks in factory service documentation, but this block's own configuration is not separately documented in available sources. |
| 79Z | D7H and D7H LGP, Series II, Power Shift transmission, lever (clutch/brake) steering | Manual break covers roughly the first 4000 units of this block, then a second break starting around unit 4000. Grouped with 80Z in the same factory Series II Power Shift parts book, covering D7H and D7H LGP together rather than one config alone. A documented field unit early in this block carries Power Shift transmission with lever steer. 3306 diesel. |
| 80Z | D7H and D7H LGP, Series II, Power Shift transmission, lever (clutch/brake) steering | Manual break starts around unit 4000 of this block. Grouped with 79Z in the same factory Series II Power Shift, lever-steer parts book, covering D7H and D7H LGP together. Which of the paired blocks maps to Std vs LGP specifically is not separately documented - confirm with dealer. |
Frequently asked questions
What engine does the Caterpillar D7H use?
A Cat 3306 turbocharged diesel, a 10.5-liter (640 cu in) inline engine. The original D7H is rated at about 231 hp (172 kW) gross / 215 hp (160 kW) net; the D7H Series II (1991 onward) carries an updated rating of roughly 230 hp (172 kW) net, though some spec listings show different gross figures for Series II. Treat exact numbers as varying by configuration and source.
What is the operating weight of the Caterpillar D7H?
Roughly 23-24 t (about 50,000-53,300 lb) in Standard configuration. The LGP (Low Ground Pressure) version runs heavier, around 25.9 t (about 57,000 lb), and the WDA waste-handling version sits around 24.9 t (about 55,000 lb). Blade choice and attachments such as a rear ripper add further weight, so treat these as a working range.
What replaced the Caterpillar D7H?
The Cat D7R, introduced in 1996. It carried forward the elevated-sprocket undercarriage concept the D7H introduced but added electronic engine control, moving the D7 line away from the D7H's fully mechanical powertrain.
What D7H owners discuss
What's the most common complaint owners report about the D7H's transmission?
Does the D7H's undercarriage wear any differently than an older low-drive Cat dozer?
What are the known weak points of the D7H's engine?
Is the dash warning/monitoring system reliable on a Series II D7H?
How does steering on a Series II D7H differ from the earlier D7H, and what goes wrong with it?
What should I check before buying a used D7H?
Owners mention slow or drifting blade lift on the D7H. What usually causes it?
Compiled from owner and technician discussions across the industry — experiences vary by serial range and machine history.
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