Caterpillararticulated dump truckarticulated truck

Caterpillar D350D

Maintenance schedule, common problems & OEM parts breakdown

The Caterpillar D350D is a mid-size articulated dump truck (ADT) in the roughly 30-32 tonne payload class, built for off-highway earthmoving and quarry haul work. It runs a single engine option across its production run: the Cat 3306 turbocharged, direct-injection diesel with aftercooling, inline 6-cylinder, 10.5 L (640.8 cu in) displacement, rated about 213 kW (285-286 hp) and mechanically governed with no electronic control module. A 5-speed powershift transmission drives the axles, and the same TO-4-type oil lubricates both the transmission and the wet-disc service brakes. Empty operating weight runs about 24,595-24,735 kg (54,223-54,531 lb) depending on chassis, loaded gross weight reaches roughly 56,336-56,482 kg (124,200-124,519 lb), and rated payload sits near 31.7 tonnes (about 69,977-69,988 lb). Caterpillar built the D350D roughly 1989 through 1993 under the 9RF serial prefix, following the D350C and preceding the D350E that took over the nameplate from 1993, part of a broader D-series line, alongside the related D25D, D30D, and D40D, that traces back to the DJB Engineering-built articulated trucks Caterpillar acquired rights to in the mid-1980s. It was offered in standard-axle and wide-axle chassis configurations, the two differing in overall width and dump-body capacity while sharing the same engine and driveline.

Within the D350D's own run the driveline stayed fixed: same 3306 engine, same 5-speed powershift, same TO-4 fluid strategy, with the wide-axle chassis offered as a factory option for a wider stance and a shallower, less-heaped dump body rather than a mechanical change. The bigger shift sits at the edges of the nameplate. The D350C before it and the D350E after it are separate engineering generations, and there is no factory D350D Series II; that designation belongs to the later D350E generation, worth checking before assuming two listings describe the same machine. In the used and parts market, the D350D's value is its mechanical simplicity: no ECM, no aftertreatment, and a driveline closely related to the D25D/D30D/D40D family, which keeps diagnostics straightforward and widens the pool of cross-compatible driveline parts. Surviving units are mostly older fleets and secondary markets, making documented service history and fluid-sample trends the best way to judge remaining life before buying or parting one out.

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 D350D specifications

Engine

Engine model	Cat 3306, turbocharged direct-injection diesel with aftercooling (DITA configuration)
Cylinders	6, inline
Gross power	213 kW (285-286 hp)
Displacement	10.5 L (640.8 cu in)
Emissions certification	Not emissions-tiered; production run ended before nonroad diesel emissions-tier regulations took effect

Weights

Operating (empty) weight - standard axle	24,595 kg (54,223 lb)
Operating (empty) weight - wide axle configuration	24,735 kg (54,531 lb)
Gross (loaded) weight - standard axle	56,336 kg (124,200 lb)
Gross (loaded) weight - wide axle configuration	56,482 kg (124,519 lb)
Rated payload	31,738-31,743 kg (69,977-69,988 lb), varies by axle configuration

Dimensions

Overall length - standard axle	9.96 m (32.65 ft)
Overall length - wide axle configuration	10.09 m (33.11 ft)
Overall width - standard axle	3.00 m (9.85 ft)
Overall width - wide axle configuration	3.30 m (10.83 ft)
Overall height	3.33 m (10.93 ft), both configurations
Wheelbase - standard axle	5.89 m (19.33 ft)
Wheelbase - wide axle configuration	6.02 m (19.76 ft)
Dump (body raised) height - standard axle	6.52 m (21.4 ft)
Dump (body raised) height - wide axle configuration	6.46 m (21.2 ft)

Performance

Maximum travel speed	48.1 km/h (29.9 mph)
Transmission	5-speed powershift
Tire size	26.5x25 radial
Body capacity, heaped - standard axle	20.5 m3 (26.8 yd3)
Body capacity, struck - standard axle	16.0 m3 (20.9 yd3)
Body capacity, heaped - wide axle configuration	20.0 m3 (26.2 yd3)
Body capacity, struck - wide axle configuration	14.0 m3 (18.3 yd3)

Service capacities (summary)

Fuel tank

450 L (118.9 gal)

Values vary by configuration, region, and serial range — confirm against your machine before planning transport or lifts.

D350D fluids & capacities

System	Capacity	Recommended fluid
Engine crankcase (with filter) - Cat 3306 turbocharged diesel, 10.5 L (640 cu in) inline-6, approx. 213 kW (285 hp) gross	Not published for the D350D specifically in sources found. The 3306 engine block runs roughly 27 L (7.2 US gal) with filter at the engine level; confirm the truck-installed figure on the machine's OMM decal or with your dealer.	Cat Diesel Engine Oil (DEO); pick the multigrade viscosity from the Cat DEO chart for the expected ambient temperature at service.
Cooling system	Not published for the D350D specifically. 3306-family engine-only figures run about 16-18 L (4.2-4.8 US gal), varies by configuration; the installed truck system (radiator, hoses, expansion tank) holds more than the bare engine. Confirm on the machine or with your dealer.	Cat Extended Life Coolant (ELC) or a Cat-approved glycol/water antifreeze mixed to the ratio shown on the machine's cooling system chart.
Fuel tank	450 L (118.9 US gal)	No. 2-D diesel fuel meeting Cat's fuel specification; switch to a winterized blend or use a cold-flow additive in cold climates.
Powershift transmission (5-speed)	Not published for the D350D in sources found - check the OMM decal or your dealer for the exact fill.	Cat TDTO (Transmission/Drive Train Oil), TO-4 spec, viscosity grade selected by ambient temperature.
Front axle differential and final drives	Not published for the D350D in sources found - verify with your dealer.	Cat TDTO (Transmission/Drive Train Oil), TO-4 spec, viscosity grade selected by ambient temperature.
Rear tandem differentials and final drives (center and rear axles)	Not published for the D350D in sources found - verify with your dealer.	Cat TDTO (Transmission/Drive Train Oil), TO-4 spec, viscosity grade selected by ambient temperature.
Hydraulic system and tank (steering, hoist, brakes)	Not published for the D350D in sources found - verify with your dealer.	Caterpillar Hydraulic Oil (HYDO) or an approved TO-4 equivalent; select viscosity grade by ambient temperature per the machine's hydraulic chart.
Grease points (chassis, pins, articulation joint)	N/A - spec only, no reservoir capacity.	Cat Multipurpose Grease (NLGI-2 lithium-complex equivalent), applied per the lubrication schedule.

Capacities are refill values from factory literature — always fill to the dipstick/sight gauge, not the number.

Caterpillar D350D maintenance schedule

Service interval	Tasks
Every 50 h	Check engine oil, coolant, and fuel levels, and drain water and sediment from the fuel/water separator before starting. Walk around the machine and check for TO-4 and hydraulic oil leaks at the hitch, axles, and dump-body hoist cylinders. Test the service and parking brakes and confirm the brake-system warning indicator before moving the truck. Grease the oscillating hitch pins and articulation joint at every fitting. Check tire pressure and inspect the 26.5x25 radials for cuts, cracks, or uneven wear.
Every 250 h	Change engine oil and filter on the 3306. Service the air cleaner primary element and replace it if the restriction indicator shows red. Check alternator, fan, and water pump belt tension and condition. Check battery electrolyte level and clean the terminal connections. Pull engine oil, TO-4, and hydraulic oil samples for S.O.S analysis. Inspect the wiring harness near the hitch and hydraulic lines for chafe from articulation flex.
Every 500 h	Change the transmission/brake system oil filter. Check differential and final drive oil levels on both axles and top off as needed. Check wheel bearing oil level front and rear. Clean the radiator core and oil cooler fins of built-up debris. Inspect dump-body hoist cylinder mounts, pins, and hoses for wear or leaks. Check the fuel ratio control valve line at the back of the injection pump for oil, an early sign of diaphragm wear.
Every 1,000 h	Change the TO-4 oil and filter shared by the powershift transmission and wet-disc brakes. Change differential and final drive oil in both axles. Check and adjust valve lash on the 3306. Inspect the turbocharger for shaft play and boost leaks. Check and adjust articulation and oscillation bearing clearances at the hitch. Check the parking brake accumulator precharge and charging-valve operation.
Every 2,000 h	Change hydraulic tank oil and filter. Check and adjust fuel injection timing on the mechanically governed 3306. Inspect engine, radiator, and cab mounts for wear or cracking. Flush the cooling system and check corrosion inhibitor concentration. Inspect powershift clutch packs and modulation for wear trends.
Every 4,000 h	Inspect the oscillating hitch casting and front oscillation trunnion for cracking and excess play. Inspect wet-disc brake packs for wear and pressure-test the brake circuit. Rebuild or inspect steering cylinders, pins, and bushings. Inspect the frame, dump-body pivot pins, and hoist mounts for stress cracks.
Every 6,000 h	Evaluate cylinder liner and piston wear on the 3306 if oil consumption or blow-by has been trending up. Rebuild the injection pump governor and fuel ratio control assembly as part of a full fuel-system overhaul. Rebuild the differential and final drive assemblies if S.O.S trends indicate advancing wear. Rebuild the powershift transmission clutch packs and torque-converter components as indicated by sample and performance history. Fully drain and refill the cooling system with fresh coolant and inhibitor package.

Servicing the D350D beyond the schedule

Predictive Maintenance & Fluid Analysis

The D350D predates onboard diagnostics, so fluid sampling carries the load. Pull S.O.S samples from the 3306 crankcase, the TO-4 oil shared by the powershift transmission and wet-disc brakes, the differentials, and the hydraulic tank on a fixed interval. Rising wear metals in the shared TO-4 supply can signal brake-disc glazing or clutch-pack wear before it shows at the pedal. Track soot loading and TBN in engine oil since injection timing drifts gradually on a mechanically governed pump, not through a fault code.

Corrective & Common Repairs

The 3306's common failure mode under load is smoke and lost power traced to the fuel ratio control valve behind the injection pump (a ruptured diaphragm lets oil cross into the air side) rather than the turbocharger itself. A weak fuel transfer pump mimics the same symptoms once the tank runs low. The spring-applied, hydraulically-released parking brake depends on accumulator precharge; one that reapplies early points there, not a worn brake pack. Hitch pins, steering cylinder pins, and the front oscillation trunnion round out the recurring wear list.

Overhaul & Rebuild Points

Top-end overhaul on the 3306 comes due once compression and blow-by trend past normal on oil-sample data; expect liner, piston, and injector work at that stage. The 5-speed powershift eventually needs a clutch-pack rebuild, usually flagged by slipping shifts and metal in the TO-4 oil. Differentials and final drives on both standard- and wide-axle chassis are rebuilt as a set once gear wear shows in sampling. The hitch trunnion bushings and wet-disc brake packs are the other major wear items worth budgeting for at a full driveline rebuild.

Seasonal & Environment Servicing

Cold starts on the mechanically governed 3306 need the right TO-4 viscosity grade and functioning starting aids; run winter-grade fuel in the 450 L tank to avoid gelling. In hot, dusty applications, shorten the air-cleaner service interval and clean the radiator and oil cooler fins more often, since the turbocharged engine is sensitive to restricted airflow. Wet-season work calls for more frequent greasing at the oscillating hitch and articulation joint, plus a closer eye on the wet-disc brake seals where water and mud collect around the axle housings.

D350D common service parts

Part number	Part	Notes
8M-3182	Spring,Helical,Comp Engine Oil Filter Assembly	Lubrication service	Check fitment →
2P-2537	Stud Engine Oil Filter	Lubrication service	Check fitment →

Always confirm against your machine's serial number — cross-check any part in Heavy Parts AI before ordering.

D350D fault codes & troubleshooting

Code	Meaning	Likely cause	What to do
100-03 / 100-04	Engine Oil Pressure sensor circuit reads above or below the valid signal range	Open or shorted wiring at the oil pressure sender, corroded connector, or a failed sender rather than a real pressure loss	Check sender wiring and connector for an open or short before condemning the sender; confirm actual pressure with a mechanical test gauge
110-03 / 110-04	Engine Coolant Temperature sensor circuit reads above or below the valid signal range	Open or shorted wiring at the coolant temperature sender, corroded connector, or a failed sender	Inspect the sender harness and connector, verify actual temperature with a handheld probe, replace the sender only after wiring checks good
111-02	Engine Coolant Level sensor signal is erratic or intermittent	Coolant level near the probe tip, a corroded probe, or a loose connector causing an intermittent signal	Check actual coolant level and top off as needed, clean and inspect the level probe and its connector
096-03 / 096-04	Fuel Level sender circuit reads above or below the valid signal range	Open or shorted wiring to the tank sending unit, a stuck float, or a failed sender	Check harness continuity to the sender and float movement, replace the sender only if wiring tests good
177-03 / 177-04	Transmission/torque converter oil temperature sensor circuit reads above or below the valid signal range	Open or shorted wiring or connector at the transmission oil temperature sender	Inspect the harness and connector, confirm actual temperature with a handheld probe, replace the sender only if wiring checks good
168-02	Electrical system (battery/charging) voltage is erratic or out of normal range	Loose or corroded battery terminals, a failing alternator, or a bad ground strap	Load-test the battery, check alternator output and drive belt, clean and tighten all battery and ground connections
Low Engine Oil Pressure warning lamp / action alarm	Actual engine oil pressure has dropped below the safe operating threshold; this is the most common real-world alert on this machine, separate from a stored circuit code	Low oil level, a plugged oil filter, a worn oil pump, or a failed pressure sender	Shut down promptly, check oil level and filter condition, confirm true pressure with a mechanical gauge before returning to service
High Coolant Temperature warning lamp / action alarm	Actual coolant temperature has risen above the safe operating threshold	Low coolant, a blocked radiator core or fan drive issue, a stuck thermostat, or a failing water pump	Shut down and let the engine cool, check coolant level and look for leaks, inspect the radiator, fan drive, and thermostat

Codes and remedies are general guidance for this model family — always confirm with diagnostic tooling and your dealer before major repairs.

D350D attachments & work tools

Dump body / rated capacity class

Standard steel dump body, struck capacity about 14.0-16.0 m3 (18.3-20.9 yd3) and heaped capacity about 20.0-20.6 m3 (26.2-26.9 yd3), varies by configuration/series across dealer spec sheets. Rated payload is about 31.7 t (roughly 69,980 lb).

Wide-axle chassis configuration

A wide-axle version of the D350D is listed separately from the standard-gauge unit, with greater overall width and a longer wheelbase (overall length about 10.1 m / 33.1 ft vs 9.95 m / 32.65 ft standard). Same engine, capacity, and payload rating as the standard unit; the wider stance is a factory chassis option for stability rather than a bolt-on attachment.

Tailgate and body-discharge control

Standard rear tailgate contains material during haul and travel. For sticky or wet loads that resist a normal dump cycle, rear-eject (ejector) bodies that push the load off the chassis are offered for this size class by specialist truck-body builders as a body swap, not a Cat quick-attach work tool.

Wear liners and spill guards

Abrasion-resistant liner plate and impact liners for the body floor/sides, plus tailgate spill guards to reduce carryback, are standard options across Cat's haul-truck body lineup for abrasive or sticky material. Treat sizing/fitment as class-typical rather than confirmed on a specific D350D document.

Articulation and oscillation hitch (frame coupling)

This machine class has no quick-attach work-tool coupler; the functional 'mounting' system is the oscillating hitch frame joining the front tractor half to the rear dump-body frame half, allowing the frames to articulate for steering and oscillate independently over rough terrain. This hitch/steering arrangement is documented in Cat service literature covering the D-series articulated truck line that includes the D350D.

Tires

Standard fitment is 26.5x25 radial earthmover tire on both standard and wide-axle D350D configurations. Bias-ply tires in the same nominal size are a common industry alternative for rock/quarry duty in this class, though not confirmed as a listed factory option for this specific model.

Powertrain and why there is no work-tool ecosystem

Power comes from a Caterpillar 3306 turbocharged diesel rated about 213 kW (285-286 hp) through a 5-speed automatic powershift transmission. As an articulated dump truck the D350D hauls loose material only; it does not run interchangeable buckets, forks, blades, or hydraulic work tools the way a loader or excavator does, so 'attachments' for this model are body/chassis configuration choices rather than a coupler-based tool line.

All D350D assemblies by section

Every catalogued assembly group for the Caterpillar D350D. Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.

Basic Engine

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
0S***18	Bolt; (5/16-18x1-In)(Hydraulic Pump)	2

See all parts with full part numbers in Heavy Parts AI →

Engine Arrangement

284-3287 Conversion Ar-Engine

0R***14	Rod As-Connecting	1
0R***97	Cylinder Pack Group	6
0R***82	Injector As	6
10***92	Pump Group-Gov & Fuel Inj	1

See all parts with full part numbers in Heavy Parts AI →

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
4N***61	Bolt 165.1 mm(6.5 In.) Long	4

See all parts with full part numbers in Heavy Parts AI →

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
2A***46	Bolt,Machine Governor Linkage Bracket	2

See all parts with full part numbers in Heavy Parts AI →

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
15***28	Gasket-Governor	1

See all parts with full part numbers in Heavy Parts AI →

115-9595 Pump Gp-Fuel Injection

0S***15	Bolt 19 mm (.75 In.) Long Return Air Console To Enclosed Rops	4
11***18	Seal-O-Ring; (26.64mm Id)	6
11***95	Pump Group-Fuel Injection	1
11***96	Camshaft As-Fuel Inj Pump	1

See all parts with full part numbers in Heavy Parts AI →

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
6I***27	Bonnet-Valve	1

See all parts with full part numbers in Heavy Parts AI →

7c-8992 Seal Gp-Pump

03***79	Seal-O-Ring (Id=10.82mm)	1
14***77	Gasket	1
15***26	Gasket	1
15***27	Gasket-Fuel	1

See all parts with full part numbers in Heavy Parts AI →

1w-1597 Torque Control Gp

1P***52	Insulator,Bushing Governor	1
1W***97	Torque Control Group	1
2P***85	Spacer (.635 mm Thk); (0.635-mm Thk)	1
2W***34	Bar-Load Stop; (4.0mm Thk)	1

See all parts with full part numbers in Heavy Parts AI →

Service Equipment And Supplies

284-3299 Kit-Engine Parts

10***68	Hose As	1
10***69	Tube As; (Oil)	1
12***74	Clip-Loop; (12.7mm Id)	1
12***94	Bolt-Tamperproof; (28.58mm)	1

See all parts with full part numbers in Heavy Parts AI →

D350D serial number reference

The PIN plate sits on the truck frame, typically on the right-hand side near the cab/articulation area, with a duplicate data plate on the engine itself. Read it as a 3-letter prefix (build series) followed by a 5-digit sequence number, e.g. 9RF00460 — the prefix pins down which service manual and parts range apply, the digits track that individual unit off the line.

Prefix	Identifies	Notes
9RF	D350D articulated truck, standard production run	Main PIN prefix for the D350D (9RF00001 and up). Documented in the factory service manual set for this range and matched to real field units — 1991-1992 D350D trucks carrying PINs in the 9RF00300-9RF00460 span, all fitted with the Cat 3306 diesel (3306B noted on field nameplates). Expect this prefix on a genuine D350D.
3AJ	D350D articulated truck, early/combined-family build (confirm with dealer)	Covers 3AJ00001-00414. Caterpillar's own service documentation for this range is published jointly for the D25D, D30D and D350D articulated truck family (shared chassis/driveline lineage from the DJB-built line), and at least one separate parts reference ties this same range to the D30D specifically. No field-verified D350D unit carrying a 3AJ PIN turned up. Treat as unconfirmed for D350D — check the PIN plate against your dealer before ordering parts.

Frequently asked questions

What engine does the Caterpillar D350D use?

A Cat 3306 turbocharged, direct-injection diesel with aftercooling: inline 6-cylinder, 10.5 L (640.8 cu in) displacement, rated about 213 kW (285-286 hp). It is mechanically governed with no electronic control module, consistent with Caterpillar's pre-electronic engine generation of that era.

What is the operating weight of the D350D?

Empty operating weight runs about 24,595-24,735 kg (54,223-54,531 lb) depending on standard- or wide-axle chassis. Loaded gross weight reaches roughly 56,336-56,482 kg (124,200-124,519 lb), with a rated payload near 31.7 tonnes (about 69,977-69,988 lb).

What replaced the Caterpillar D350D?

The D350E took over the nameplate from 1993. There is no factory D350D Series II; that name belongs to a later D350E-generation update, so a listing using that term describes the newer machine, not the D350D.

What D350D owners discuss

The D350D loses power and smokes heavily once it's under load. What's the usual cause?

On the 3306 turbocharged and aftercooled engine, black smoke under load with a power drop is more often boost related than a straight fuel problem. Work it in order: air filter and intake restriction first, then boost leaks at the turbo boots and aftercooler tubing, then the fuel ratio control (air-fuel ratio) valve at the back of the injection pump. A ruptured diaphragm in that valve lets oil cross into the air side, which shows up as smoke and soft power together. Pull the air line off the back of the valve and check for oil before condemning the turbo itself. A worn fuel transfer pump can mimic the same symptoms by starving the injection pump once the engine is loaded.

The truck cuts out and won't restart once the tank runs below about half full, but it's fine on a full tank. What's going on?

This points to a weak fuel transfer pump rather than anything in the injection pump. A pump that has lost its internal seal can still pull fuel off the top of a fuller tank but can't generate enough lift once the level drops, so the engine starves and dies. Pressure-test at the filter housing; a healthy pump holds a steady supply pressure, and a pump reading close to nothing is done and needs to be rebuilt or replaced. Rule out a collapsed fuel line or a cracked suction line drawing air before committing to the pump.

What oil actually belongs in the D350D's transmission and brakes?

The 5-speed powershift and the oil-immersed disc brakes both run on a TO-4 type powershift/hydraulic oil, not automotive brake fluid. TO-4 carries the friction-modifier package the wet clutches and brake discs need; DOT 3 or DOT 4 attacks seals and glazes the friction material over time. Confirm the exact viscosity grade and change interval for your serial range in the machine's operation and maintenance manual before a service, since running the wrong fluid is one of the costlier mistakes owners make on this family of truck. Have your dealer verify the correct fluid and interval for your specific serial number before any fluid change.

The parking brake releases fine at startup, but a few minutes after shutdown it looks like it's already reapplied. Is that normal?

It can be, to a point. These trucks use a spring-applied, hydraulically-released parking brake, so the spring is what actually sets the brake and oil pressure is what holds it off. That release pressure is held in an accumulator, which is why the brake can still be released a handful of times after the engine is shut down before the spring wins back. If it reapplies almost immediately with the engine running, or won't release at all, check the accumulator precharge and the charging valve before assuming the brake pack itself is worn. Have your dealer verify accumulator precharge and brake pump output before returning the truck to service.

What wear points should I keep an eye on at the center hitch and axle oscillation?

The articulation (hitch) pins and bushings and the steering cylinder pins are usually the first things to show play, showing up as a clunk on direction changes or when the dump body is raised and the rear end settles. A simple check is to have someone stand well clear behind the truck and watch the hitch while the box is raised; any looseness there is worth investigating before it turns into an expensive repair. The front axle oscillation trunnion is the other high-wear pivot on this style of truck. Both points are on a grease schedule in the maintenance manual, and machines kept to that schedule rarely show early play.

What should I check before buying a used D350D?

Start with the hitch and articulation joint: raise the dump body and watch for play at the pins as above. Run the engine cold and watch the exhaust for smoke, listen for turbo whine or knock, and check for oil weeping around the engine and hoist valve. Cycle the transmission through every gear, forward and reverse, and confirm it shifts cleanly without hunting. Check that the parking brake releases and holds and that the brake pressure warning stays off at idle. Walk the tires and rims for wear and cuts, and check the frame and dump body for cracks or repair welds around the hoist mounts. Ask for service records and compare hour meter wear against the condition of the seat, pedals, and steering wheel. A pre-purchase inspection by an independent mechanic is worth the cost on a machine this age.

Gauges on the D350D read wrong or flicker on and off. Is it the sensor or something else?

On a truck of this generation the gauges run off simple sender units rather than a full electronic monitoring system, so an odd reading is more often a bad connection than a failed sender. Check the sender's connector for corrosion or a backed-out pin first, and check the wiring harness for chafe points near the hitch and hydraulic lines, since flexing at the articulation joint is hard on harness runs over the years. If the reading stays steady but is clearly wrong compared to a mechanical test gauge at the same point, the sender itself is the likely culprit.

Compiled from owner and technician discussions across the industry — experiences vary by serial range and machine history.

Need a specific D350D part?

Search live OEM part data, check fitment, and cross-reference alternatives with Heavy Parts AI.

Search parts in the app