Caterpillarroad reclaimersoil stabilizer
Caterpillar SS-250
Maintenance schedule, common problems & OEM parts breakdown
The Caterpillar SS-250 is a self-propelled, wheeled soil stabilizer and road reclaimer built around a chain-driven rotor that pulverizes and mixes pavement or subgrade material in a single pass. Caterpillar sold it alongside a near-identical reclaimer variant, the RR-250, with both riding on a rear-steer, four-wheel chassis and a roughly 2438 mm (96 in) mixing chamber. Power came from Caterpillar's 3406-series inline-six diesel: the base machine (6DD prefix) carries a 3406B rated near 335 gross hp (250 kW), and the updated SS-250B (5GR prefix) carries a plain 3406 rated at the same 335 gross hp per factory literature. A higher-output 3406C DITA rating near 430 hp appears in some secondary listings but is not confirmed for this chassis; a small number of listings also cite a Cummins-powered variant, and neither should be treated as the norm without confirming the specific unit's engine tag. Operating weight varies with configuration, ballast, and rotor fitted, spanning roughly 12,900 to 16,000 kg (28,500 to 35,200 lb) across sources. Working depth is quoted from 0 to 406-457 mm (16-18 in) depending on the rotor and series. Serial number records place production through the mid-1980s into the mid-1990s, with an updated SS-250B/RR-250B series carrying the design into the later 1990s and 2000s.
Across its life the SS-250/SS-250B line stayed mechanically conservative: a down-cut, chain-driven rotor, a mechanical or powershift transmission, and a 3406-family diesel with no electronic engine controls. Later B-series machines shared service parts with Caterpillar's RM-350B and RM-250C reclaimers, showing the platform was kept in production and cross-supported even as Caterpillar began developing a fully redesigned rotary mixer line. That redesign arrived as the RM300 and RM500 (and later RM500B), which moved to electronically controlled ACERT engines, up-cut rotor designs, and factory ROPS/cab options - a clean break from the SS-250's mechanical architecture. For the used and parts market today, the SS-250 remains a low-cost entry point into full-depth reclamation and stabilization work: the mechanical drivetrain is straightforward to maintain and rebuild without proprietary electronics, wear parts (chain case components, wear skis, cutting bit holders) are simple bolt-on or weld-on items, and surviving units are commonly sourced for parts to keep RR-250, SS-250B, and RR-250B siblings running.
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 SS-250 specifications
Engine
| Engine model | Cat 3406 / 3406B, inline-6, 4-stroke turbocharged diesel. Dealer listings for SS-250 machines (6DD serial prefix) name the 3406B specifically; factory service documentation for the RR-250 counterpart (6ED prefix) groups the power train under the 3406 engine family. |
| Gross power | 335 hp (250 kW) at rated speed |
| Net power | Not published in available spec sources |
| Displacement | 14.6 L (893 cu in) |
| Cylinders | 6, inline |
| Emissions tier | Mechanical, pre-electronic diesel; predates EPA nonroad Tier certification (machine generation is mid-1980s to mid-1990s) |
Weights
| Operating weight (base SS-250) | Reported 12 927 to 15 967 kg (28,500 to 35,200 lb) depending on individual unit and options; varies by configuration |
| Operating weight (SS-250B) | Approx. 13 290 kg (29,300 lb) for the later B-series machine |
| Shipping weight | Not separately published; use operating weight for transport planning |
| Ground pressure | Not published |
Dimensions
| Transport length | 8.79 m (28 ft 10 in) |
| Transport width | 2.92 m (9 ft 7 in) on base SS-250 listings; 3.00 m (9 ft 10 in) reported for SS-250B — varies by tire/track configuration |
| Transport height | 3.23 m (10 ft 7 in) |
| Rotor / mixing chamber width | 2.44 m (8 ft / 96 in) |
| Wheelbase / ground clearance | Not published in available spec sources |
Performance
| Mixing / working depth | 0 to 406 mm (0 to 16 in) working depth per dealer spec sheet; treat as configuration-dependent |
| Travel speed | Not documented in available spec sources for this model — verify with dealer or original brochure |
| Gradeability | Not published |
| Drive configuration | Documented examples show 2-wheel drive; some listings reference 4-wheel drive — varies by unit/options |
Service capacities (summary)
| Fuel tank | Not publicly documented for this model — verify with dealer or original brochure |
| Hydraulic system | Not publicly documented for this model |
| Engine oil | Not publicly documented for this model; follow Cat 3406/3406B engine service literature |
| Cooling system | Not publicly documented for this model |
Values vary by configuration, region, and serial range — confirm against your machine before planning transport or lifts.
SS-250 fluids & capacities
| System | Capacity | Recommended fluid |
|---|---|---|
| Engine crankcase (with filter) - Cat 3406B 6-cylinder diesel | approx. 41.6 L (11.0 US gal) per the 3406B industrial/gen-set engine refill chart; this is the engine-only reference figure, not a confirmed SS-250 installed-total - verify against the machine OMM or dealer | Cat DEO (Diesel Engine Oil), API CD/CE-class multigrade for the era; select SAE viscosity grade by ambient temperature per Cat's standard multigrade chart - exact SS-250 OMM viscosity-by-climate table not found in accessible sources |
| Cooling system | approx. 68.1 L (18.0 US gal) per the 3406B industrial/gen-set engine refill chart; engine-only reference figure, machine-installed radiator/hose total not confirmed - verify with dealer/OMM | Cat DEAC (Diesel Engine Antifreeze/Coolant), full-strength or diluted per climate; later-production units of this era sometimes moved to Cat ELC - exact spec called out in the SS-250 OMM not confirmed |
| Fuel tank | not documented in accessible sources for this specific serial range - verify with dealer/OMM | ultra low sulfur No. 2-D diesel fuel per Cat's standard era recommendation; exact tank spec not confirmed |
| Power train / drive system (self-propelled wheel drive) | not documented in accessible sources - verify with dealer/OMM | Cat TDTO (Transmission and Drive Train Oil, TO-4 spec), the standard Cat fluid for powershift/hydrostatic drive compartments of this machine class and era |
| Final drives (each, if equipped) | not documented in accessible sources - verify with dealer/OMM | Cat TDTO (TO-4 spec), per standard Cat final-drive practice for this machine class |
| Hydraulic system (implement, steering, rotor drive) and tank | not documented in accessible sources - verify with dealer/OMM | Cat TDTO (TO-4 spec) is Cat's standard shared hydraulic/drive-train fluid for construction machines of this era and class; exact SS-250 spec not confirmed |
| Grease (spec only) | not applicable - grease points serviced per OMM lubrication schedule, no reservoir capacity | Cat Multipurpose Grease (NLGI 2), standard Cat chassis grease for this machine class and era |
Capacities are refill values from factory literature — always fill to the dipstick/sight gauge, not the number.
Caterpillar SS-250 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 |
|
Servicing the SS-250 beyond the schedule
Predictive Maintenance and Fluid Analysis
Pull oil samples from the 3406-series diesel and the rotor chain case at every 250-hour service to catch abrasive wear metals before they cause chain or sprocket failure. Because the rotor works in wet reclamation slurry and stabilization additives, check hydraulic and chain case oil for water intrusion at each interval. Track coolant condition on the 3406 block, which is sensitive to liner cavitation without proper additive levels. Rising rotor bearing temperature or chain case oil discoloration are the earliest warning signs of drive wear.
Corrective and Common Repairs
Expect frequent bit and bit-holder replacement on the down-cut rotor from abrasive base material and reclaimed asphalt. Chamber wear skis and the rear door strike-off wear through from constant material drag and need routine replacement. Chain stretch in the rotor drive case shows up as inconsistent mixing depth and rotor speed loss. Hydraulic cylinder seals on the depth-control and rear-steer circuits are common leak points given the machine's age and duty cycle. PTO/rotor clutch slippage is a frequent complaint on higher-hour units.
Overhaul and Rebuild Points
The rotor chain case - chain, sprockets, and rotor bearing - is the highest-wear major assembly and the usual overhaul target on a used SS-250. The 3406-series engine typically needs an inframe overhaul (liners, pistons, injectors) as hours accumulate, since these blocks were built for heavy sustained load. Transmission or PTO clutch packs and final drive planetary gears are secondary rebuild candidates. Rotor chamber housing and wear ski replacement should be planned together, since they wear at similar rates under the same abrasive exposure.
Seasonal and Environment Servicing
Cold climates need block heaters, fuel anti-gel additive, and coolant freeze protection checked before the 3406-series diesel is asked to start in low temperatures. Hot, dusty reclamation sites demand more frequent radiator core cleaning and air filter service, since pulverized asphalt and aggregate dust load the cooling stack quickly. Wet stabilization jobs put extra strain on chain case seals and the water/emulsion spray plumbing, both of which should be inspected for contamination or corrosion after extended wet-weather work.
SS-250 common service parts
| Part number | Part | Notes | |
|---|---|---|---|
| 7R-3004 | Element As-Measuring | Scheduled service item | Check fitment → |
Always confirm against your machine's serial number — cross-check any part in Heavy Parts AI before ordering.
SS-250 fault codes & troubleshooting
| Code | Meaning | Likely cause | What to do |
|---|---|---|---|
| 22 | Rack position sensor fault | Fuel rack position sensor/transducer signal open, shorted, or out of range; damaged transducer or chafed harness at the fuel control housing | Inspect the rack position sensor wiring and connector for corrosion or pinched wires, then test the transducer per the engine service manual and replace if out of spec |
| 23 | Timing position sensor fault | Faulty injection timing sensor or damaged sensor wiring/connector | Inspect timing sensor connector and harness, check sensor air gap, test sensor output against spec |
| 24 | Oil pressure sensor fault | Failed oil pressure sensor/transducer or open/shorted wiring; sensor shares wiring with the rack position circuit on this engine | Verify actual oil level and pressure first, then inspect sensor wiring and connector, test and replace the transducer if faulty |
| 25 | Boost pressure sensor fault | Failed boost pressure sensor, plugged sense line, or wiring fault | Inspect sensor and its air sense line for blockage or damage, check connector, test sensor and replace if out of range |
| 34 | Loss of engine RPM signal (engine speed/timing sensor fault) | Failed engine speed/timing sensor at the fuel rack end cap, excessive sensor air gap, or damaged wiring | Inspect the speed/timing sensor and connector, check and reset air gap to spec; engine may run rough, fail to start, or stall until corrected |
| 35 | Engine overspeed warning | Engine exceeded rated governed speed, often from a downhill grade in the wrong gear, driveline issue, or governor malfunction | Review operating conditions at the time of the code, check governor and linkage for binding, inspect driveline for a cause of overspeed |
| 21 | Sensor supply voltage fault | Low or out-of-range voltage on the shared sensor supply circuit; corroded connector or failing ECM voltage regulator | Check sensor supply wiring and connector for corrosion, measure supply voltage at the ECM, repair or replace as needed |
| 01 | Override of idle shutdown timer | Clutch or service brake pedal pressed while the idle shutdown timer is counting down; not a component failure | No repair needed; this is an informational log entry confirming the shutdown timer was reset by pedal input |
| 55 | No detected faults | System operating normally at time of check; a real fault may have self-cleared or logged fault history remains stored | No repair action required; review logged (inactive) code history separately if an intermittent problem is still suspected |
Codes and remedies are general guidance for this model family — always confirm with diagnostic tooling and your dealer before major repairs.
SS-250 attachments & work tools
Reclaiming/mixing rotor
Main work tool is a single rotary mixing drum spanning roughly 2.4 m (8 ft), matched to the machine's fixed mixing chamber. Working/milling depth is rated in the 400-460 mm (16-18 in) range depending on source and series, so treat depth as a range rather than a fixed figure.
Coupler/mounting system
Rotor is not a quick-coupler excavator-style attachment; it is an integral driveline component pinned/bolted inside the mixing chamber and driven by the machine's own drivetrain. No universal third-party quick-hitch exists for this machine class.
Cutting bit system
Rotor carries tungsten-carbide-tipped cutter bits on a steel body, the same general bit style used across the wider Cat road reclaimer/soil stabilizer line spanning this and later RM-series machines. Bits are wear items replaced individually as they dull or break.
Bit holder / mounting
Bits seat in cast stand-off holders that are part of the rotor casting. A worn or damaged cast holder can be cut off and replaced with a weld-on holder rather than replacing the rotor segment itself.
Water spray/injection system
Machine carries an onboard spray bar and metering system feeding the mixing chamber, used to control moisture during in-place reclaiming and stabilizing passes. This is documented as a dedicated factory spray/water group in the parts catalog, not sold as an add-on accessory.
Rotor drive and guarding
Rotor is chain-driven off the machine's power train, and later-production units received an uprated drive chain rated to roughly 61,000 kg (135,000 lb) for extra durability. Drive chain and rotor housing are enclosed by factory guards/covers per the parts catalog.
Engine/power configuration
Base units (6DD prefix) use a Cat 3406B inline-six rated around 335 gross hp (250 kW); the later SS-250B (5GR prefix) carries a Cat 3406 rated at the same 335 gross hp per factory literature. A higher-output 3406C DITA variant near 430 hp shows up in some secondary listings but isn't confirmed for this chassis - verify the exact engine and rating against the machine's serial number with your dealer.
Tire/undercarriage options
Standard rolling stock is rubber pneumatic tires. Flat-proof solid cushion tires (around 53x14-24 on the rear axle) are offered as an aftermarket option for high-puncture job sites. No track undercarriage option is documented for this class.
Reclaimer vs stabilizer badge configuration
The same base chassis and rotor/mixing-chamber assembly is marketed under two names: RR-250 as a road reclaimer and SS-250 as an in-place soil stabilizer, carried into their B-series updates. Rotor and bit compatibility generally carries across both badges unless a source ties a part to only one.
All SS-250 assemblies by section
Every catalogued assembly group for the Caterpillar SS-250. Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.
Asphalt Spray System
8c9299 Asphalt Ar-Metric
| 5E***58 | Frame As | 1 |
| 5E***59 | Lines As | 1 |
| 5E***61 | Electrical As | 1 |
8c9298 Asphalt Ar-English
| 5E***36 | Lines As | 1 |
| 5E***58 | Frame As | 1 |
| 5E***62 | Electrical As | 1 |
5e9261 Electrical As
| 5E***61 | Electrical As | 1 |
5e9262 Electrical As
| 5E***62 | Electrical As | 1 |
7r3004 Element As
| 7R***04 | Element As-Measuring | 1 |
817900 Enclosure As-Meter
| 08***00 | Enclosure As-Meter | 1 |
5e9258 Frame As
| 5E***58 | Frame As | 1 |
5e9259 Lines As
| 5E***59 | Lines As | 1 |
5e9236 Lines As
| 5E***36 | Lines As | 1 |
9n9530 Meter Gp-Flow
| 9N***30 | Meter Group-Flow | 1 |
9n9531 Meter Gp-Flow
| 9N***31 | Meter Group-Flow | 1 |
7x7439 Pump & Meter Gp
| 7X***39 | Pump & Meter Group | 1 |
5e9260 Pump & Meter Gp
| 5E***60 | Pump & Meter Group | 1 |
7x4246 Pump Gp-Hydraulic
| 7X***46 | Pump Group-Hydraulic | 1 |
7x4246 Pump As-Hydraulic
| 7X***46 | Pump Group-Hydraulic | 1 |
7x4236 Flow Readout As
| 7X***36 | Readout As-Flow | 1 |
7x4292 Flow Readout As
| 7X***92 | Readout As-Flow | 1 |
9t8248 Rotating Gp
| 9T***48 | Rotating Group-Pump | 1 |
5e9270 Spray Bar As
| 5E***70 | Spray Bar As | 1 |
5e9277 Spray Gp
| 5E***77 | Spray Group | 1 |
7x4241 Valve As
| 7X***41 | Valve As-Flow | 1 |
9t6859 Valve Gp
| 9T***59 | Valve Group-Press & Flow Cmpnstr; (Pressure, Flow Compensator) | 1 |
Basic Engine
7w3798 Camshaft Gp-Single
| 7W***98 | Camshaft Group; -Single | 1 |
8n9244 Camshaft Gp-Single
| 8N***44 | Camshaft Group-Single | 1 |
9n0684 Cover Gp-Cylinder Block
| 9N***84 | Cover Group-Cylinder Block; Cylinder Block Cover Group | 1 |
4n4792 Cover Gp-Flywheel Housing
| 4N***92 | Cover Group-Flywheel Housing; Flywheel Housing Cover Group | 1 |
1w1395 Cover Gp-Front Housing
| 1W***95 | Cover Group-Front Housing; Front Structure Cover Gp | 1 |
7c0730 Cover Gp-Valve Mechanism
| 7C***30 | Cover Group-Valve Mechanism | 1 |
4n2272 Cover Gp-Valve Mechanism
| 4N***72 | Cover Group-Valve Mechanism; Valve Mechanism Cover Group | 1 |
1w6207 Crankshaft As*R
| 1W***07 | Crankshaft As | 1 |
4n0741 Crankshaft Gp
| 4N***41 | Crankshaft Group; Crankshaft Group | 1 |
4n0741 Crankshaft Gp-Type 1
| 4N***41 | Crankshaft Group; Crankshaft Group | 1 |
8n9267 Cylinder Block Gp*R
| 8N***67 | Cylinder Block Group; Cylinder Block Group | 1 |
2w6039 Cylinder Block Gp*R
| 2W***39 | Cylinder Block Group | 1 |
7w0009 Cylinder Head As*R-Type 1
| 7W***09 | Cylinder Head As | 1 |
7w0007 Cylinder Head As
| 7W***07 | Cylinder Head As | 1 |
7w0009 Cylinder Head As*R-Type 2
| 7W***09 | Cylinder Head As | 1 |
9y3775 Cylinder Head As
| 9Y***75 | Cylinder Head As | 1 |
1w1439 Cylinder Head Gp*R
| 1W***39 | Cylinder Head Group; Cylinder Head Group | 1 |
7w2203 Cylinder Head Gp
| 7W***03 | Cylinder Head Group | 1 |
7w2202 Cylinder Head Gp
| 7W***02 | Cylinder Head Group | 1 |
4w2436 Cylinder Head Gp*R
| 4W***36 | Cylinder Head Group; Cylinder Head Group | 1 |
6n7379 Pulley & Damper Gp
| 6N***79 | Damper & Pulley Group | 1 |
8n9653 Drive Gp-Accessory
| 8N***53 | Drive Group-Accessory; Drive Gp-Accessory-Air Compressor | 1 |
1n3970 Drive Gp-Accessory
| 1N***70 | Drive Group-Accessory; Drive Gp-Accessory-Lh | 1 |
7x8964 Engine Gp
| 7X***64 | Engine Group | 1 |
7x8903 Engine Gp
| 7X***03 | Engine Group | 1 |
4n6006 Fastener Gp-Front Housing
| 4N***06 | Fastener Group-Front Housing; Front Housing Fastener Gp | 1 |
6n1299 Flywheel Gp
| 6N***99 | Flywheel Group | 1 |
7n3060 Flywheel Gp
| 7N***60 | Flywheel Group; Flywheel Group | 1 |
8n9246 Gear Gp-Front Timing
| 8N***46 | Gear Group-Front Timing; Front Timing Gear Group | 1 |
7c5064 Gear Gp-Front Timing
| 7C***64 | Gear Group-Front Timing | 1 |
8n5965 Housing Gp-Flywheel
| 8N***65 | Housing Group-Flywheel | 1 |
8n5941 Housing Gp-Flywheel
| 8N***41 | Housing Group-Flywheel; Flywheel Housing Group | 1 |
1w1468 Housing Gp-Front
| 1W***68 | Housing Group-Front; Front Housing Group | 1 |
4n1331 Lifting Eye Gp-Engine
| 4N***31 | Lifting Group; Lifting Eye Gp-Engine | 1 |
0774402 Line As-Drive
| 07***02 | Line As-Drive | 1 |
4n0756 Pan Gp-Engine Oil
| 4N***56 | Pan Group-Oil; -Engine | 1 |
7n3516 Rod & Piston Gp
| 7N***16 | Piston & Rod Group; Connecting Rod And Piston Group | 1 |
1w9373 Piston Gp
| 1W***73 | Piston Group | 1 |
4n1045 Rocker Arm Gp
| 4N***45 | Rocker Arm Group | 1 |
6n0719 Support Gp-Engine
| 6N***19 | Support Group-Engine | 1 |
8n2020 Support Gp-Front
| 8N***20 | Support Group-Engine; Engine Support Group-Front | 1 |
777813 Line As-Drive
| 07***13 | Universal Joint Group-Pump Drive | 1 |
4w2461 Valve Mechanism Gp
| 4W***61 | Valve Mechanism Group; Valve Mechanism Group | 1 |
4n2271 Valve Mechanism Gp
| 4N***71 | Valve Mechanism Group; Valve Mechanism Group | 1 |
Brakes
7x2147 Brake Gp
| 7X***47 | Brake Group | 1 |
7x9380 Brake Gp-Hydraulic
| 7X***80 | Brake Group-Hydraulic | 1 |
0776782 Valve As-Power Brake
| 07***82 | Valve As-Power Brake | 1 |
Console/Panel
8c0123 Cab Ar
| 8C***23 | Cab Ar | 1 |
7x8888 Console Gp-Part 1 Of 3
| 7X***88 | Console Group | 1 |
7x8888 Console Gp-Part 3 Of 3
| 7X***88 | Console Group | 1 |
7x8888 Console Gp-Part 2 Of 3
| 7X***88 | Console Group | 1 |
0775922 Control As-Electrical
| 07***22 | Control As-Electrical | 1 |
7x9026 Panel As-Instrument
| 7X***26 | Kit-Panel | 1 |
Cooling System
1w8347 Aftercooler Gp-Water
| 1W***47 | Aftercooler Group-Water; Water Aftercooler Gp | 1 |
4w4251 Conditioner Gp-Coolant
| 4W***51 | Coolant Conditioner Group | 1 |
4n0729 Cooler Gp-Engine Oil
| 4N***29 | Cooler Group-Engine Oil; Engine Oil Cooler Group | 1 |
7c5430 Cover Gp-Water Outlet
| 3S***43 | Seal-Lip Type; (Water Temperature Regulator) | 1 |
| 4N***56 | Gasket-Regulator Cover; (Temperature Regulator Housing) | 1 |
| 5N***15 | Cover As-Regulating | 1 |
5n8761 Drive Gp-Fan
| 0L***70 | Bolt (2-1/4") Filler Tube Assembly To Transfer Drive Case | 6 |
| 0S***94 | Bolt (1 In. Long 3/8 In. Dia.); Plate Assembly To Support Assembly | 2 |
| 1D***66 | Bolt Bracket Assembly To Yoke | 2 |
4n2474 Lines Gp-Water-Aftercooler
| 4N***74 | Lines Group-Water; Aftercooler Water Lines Group | 1 |
4n1641 Lines Gp-Water
| 4N***41 | Lines Group-Water; Water Lines Group | 1 |
9n3288 Pump Gp-Water
| 9N***88 | Pump Group-Water; Water Pump Group | 1 |
7c4957 Pump Gp-Water*R
| 7C***57 | Pump Group-Water | 1 |
7w7019 Pump Gp-Water*R
Engine Arrangement
9e2022 Engine Ar
| 1N***70 | Drive Group-Accessory; Drive Gp-Accessory-Lh | 1 |
| 1W***57 | Mounting Group-Alternator | 1 |
| 2W***01 | Filler Group-Oil | 1 |
7c6843 Engine Ar-Part 2 Of 2*R
| 2W***81 | Pump Group-Fuel Transfer; Fuel Transfer Pump Group | 1 |
| 2W***33 | Meter Group-Service; Service Meter Group | 1 |
| 3N***90 | Plate Serial Number; On R.H. Rear Bank Of Cylinder Block As Viewed From Rear Of Engine | 1 |
4w3797 Engine Ar-Part 1 Of 2
| 1W***57 | Lines Group-Fuel Injection; Fuel Injection Lines Group | 1 |
| 1W***95 | Cover Group-Front Housing; Front Structure Cover Gp | 1 |
| 1W***39 | Cylinder Head Group; Cylinder Head Group | 1 |
7c6843 Engine Ar-Part 1 Of 2*R
| 1W***95 | Cover Group-Front Housing; Front Structure Cover Gp | 1 |
| 1W***68 | Housing Group-Front; Front Housing Group | 1 |
| 1W***76 | Fastener Group-Fuel Inj Pump; Fuel Injection Pump Fastener Gp | 1 |
4w3797 Engine Ar-Part 2 Of 2
| 2W***81 | Pump Group-Fuel Transfer; Fuel Transfer Pump Group | 1 |
| 2W***33 | Meter Group-Service; Service Meter Group | 1 |
| 3N***90 | Plate Serial Number; On R.H. Rear Bank Of Cylinder Block As Viewed From Rear Of Engine | 1 |
1383936 Engine Ar-Nonrunnable-Part 1 Of 2
| 10***47 | Alternator Group-Charging; -24-Volt, 50-Ampere | 1 |
| 13***36 | Aftercooler Group-Water | 1 |
| 13***36 | Engine Ar-Nonrunnable | 1 |
1383936 Engine Ar-Nonrunnable-Part 2 Of 2
| 13***61 | Lines Group-Fuel Injection | 1 |
| 13***36 | Engine Ar-Nonrunnable | 1 |
| 4N***33 | Pump Group-Engine Oil | 1 |
Frame
0980556 Roll Bar As
| 09***56 | Bar As-Roll; Roll Bar As | 1 |
7x8869 Mainframe Gp-Part 1 Of 5
| 7X***69 | Frame Group-Main | 1 |
7x8869 Mainframe Gp-Part 3 Of 5
| 7X***69 | Frame Group-Main | 1 |
7x8869 Mainframe Gp-Part 4 Of 5
| 7X***69 | Frame Group-Main | 1 |
7x8869 Mainframe Gp-Part 2 Of 5
| 7X***69 | Frame Group-Main | 1 |
7x8869 Mainframe Gp-Part 5 Of 5
| 7X***69 | Frame Group-Main | 1 |
8c0122 Rops Ar-Open
| 07***71 | Seat Belt As | 1 |
| 09***56 | Bar As-Roll; Roll Bar As | 1 |
| 8C***22 | Rops Ar-Open | 1 |
Fuel System And Governor
8n2177 Control Gp-Governor
| 8N***77 | Control Group-Governor; Governor Control Group | 1 |
4w4619 Drive Gp-Governor & Fuel Pump
| 4W***19 | Drive Group-Governor & Fuel Pump | 1 |
1w7376 Fastener Gp-Fuel Injection Pump
| 1W***76 | Fastener Group-Fuel Inj Pump; Fuel Injection Pump Fastener Gp | 1 |
9y1234 Fastener Gp
| 9Y***34 | Fastener Group-Fuel Inj Pump; -Governor | 1 |
8h7204 Filter Gp-Fuel
| 8H***04 | Filter Group-Fuel | 1 |
4n1981 Filter Gp-Fuel
| 4N***81 | Filter Group-Fuel | 1 |
5e9577 Fuel System
| 5E***77 | Fuel System Group | 1 |
6n8878 Gauge Gp-Fuel Pressure
| 6N***78 | Gauge Group-Fuel Pressure | 1 |
2w7325 Governor Gp-Part 3 Of 4
| 2W***25 | Governor Group | 1 |
2w7325 Governor Gp-Part 2 Of 4
| 2W***25 | Governor Group | 1 |
2w7325 Governor Gp-Part 4 Of 4
| 2W***25 | Governor Group | 1 |
2w7325 Governor Gp-Part 1 Of 4
| 2W***25 | Governor Group | 1 |
2w3452 Lines Gp-Fuel Filter
| 2W***52 | Lines Group-Fuel Filter; Fuel Filter Lines Group | 1 |
7c9937 Lines Gp-Fuel Injection
| 7C***37 | Lines Group-Fuel Injection | 1 |
4w1566 Lines Gp-Fuel Injection
| 4W***66 | Lines Group-Fuel Injection; Fuel Injection Lines Group | 1 |
7c9936 Lines Gp-Fuel Injection
| 7C***36 | Lines Group-Fuel Injection | 1 |
1w0557 Lines Gp-Fuel Injection
| 1W***57 | Lines Group-Fuel Injection; Fuel Injection Lines Group | 1 |
7c2107 Lines Gp-Fuel Injection
| 7C***07 | Lines Group-Fuel Injection | 1 |
7c3418 Lines Gp-Fuel Injection
| 7C***18 | Lines Group-Fuel Injection | 1 |
7c2108 Lines Gp-Fuel Injection
| 7C***08 | Lines Group-Fuel Injection | 1 |
7c3428 Lines Gp-Fuel Injection
| 7C***28 | Lines Group-Fuel Injection | 1 |
7c9935 Lines Gp-Fuel Injection
| 7C***35 | Lines Group-Fuel Injection | 1 |
4w7017 Nozzle As-Fuel Valve*R
| 4W***17 | Nozzle As-Fuel Valve | 1 |
4w2549 Pump Gp-Fuel Injection
| 4W***49 | Pump Group-Fuel Injection | 1 |
7e6006 Pump Gp-Fuel Injection
| 7E***06 | Pump Group-Fuel Injection | 1 |
4p1381 Pump Gp-Fuel Injection
| 4P***81 | Pump Group-Fuel Injection | 1 |
4n3287 Pump Gp-Fuel Priming
| 4N***87 | Pump Group-Fuel Priming; Pump Group-Fuel Priming | 1 |
2w4381 Pump Gp-Fuel Transfer
| 2W***81 | Pump Group-Fuel Transfer; Fuel Transfer Pump Group | 1 |
1w1700 Pump Gp-Fuel Transfer*R
| 1W***00 | Pump Group-Fuel Transfer | 1 |
2w8541 Governor & Fuel Injection Pump Gp
| 2W***41 | Pump Group-Gov & Fuel Inj; Pump Gp-Governor & Fuel Injection | 1 |
2w8628 Torque Control Gp
| 2W***28 | Torque Control Group | 1 |
Gauges And Accessories
8c0126 Indicator As
| 08***47 | Indicator As-Electrical | 1 |
| 7R***09 | Indicator As-Mechanical | 1 |
| 8C***26 | Indicator As | 1 |
0821247 Indicator As-Electrical
| 08***47 | Indicator As-Electrical | 1 |
7r2909 Indicator As-Mechanical
| 7R***09 | Indicator As-Mechanical | 1 |
2w8133 Meter Gp-Service
| 2W***33 | Meter Group-Service; Service Meter Group | 1 |
Hydraulic System
7x9185 Hood & Rotor Lift Gp-Part 4 Of 4
| 7X***85 | Lift Group-Hood & Rotor | 1 |
7x9185 Hood & Rotor Lift Gp-Part 2 Of 4
| 7X***85 | Lift Group-Hood & Rotor | 1 |
7x9185 Hood & Rotor Lift Gp-Part 3 Of 4
| 7X***85 | Lift Group-Hood & Rotor | 1 |
7x9185 Hood & Rotor Lift Gp-Part 1 Of 4
| 7X***85 | Lift Group-Hood & Rotor | 1 |
7x9603 Lines Gp-Rear Door Lift-Part 2 Of 2
| 7X***03 | Lines Group-Rear Door Lift | 1 |
7x9603 Lines Gp-Rear Door Lift-Part 1 Of 2
| 7X***03 | Lines Group-Rear Door Lift | 1 |
780287 Pump Gp-Hydraulic
| 07***87 | Pump Group-Hydraulic | 1 |
0778617 Valve As-Solenoid
| 07***17 | Valve As-Solenoid | 1 |
Intake And Exhaust System
0980930 Air Cleaner Gp
| 09***30 | Air Cleaner Group | 1 |
7x9154 Air Cleaner Gp
| 7X***54 | Air Cleaner Group | 1 |
7c6610 Cartridge Gp-Turbocharger*R
| 7C***10 | Cartridge Group-Turbocharger | 1 |
9n5263 Cartridge Gp-Turbocharger*R
| 9N***63 | Cartridge Group-Turbocharger | 1 |
5l7661 Elbow Gp-Exhaust
| 5L***61 | Elbow Group-Exhaust; Exhaust Elbow Group | 1 |
8n4398 Lines Gp-Air
| 8N***98 | Lines Group-Air; Air Lines Group | 1 |
4n5394 Lines Gp-Turbocharger Oil
| 4N***94 | Lines Group-Turbocharger Oil; Turbocharger Oil Lines Group | 1 |
4n0754 Manifold Gp-Exhaust
| 4N***54 | Manifold Group-Exhaust | 1 |
5l8632 Pipe Gp-Exhaust
| 5L***32 | Pipe Group-Exhaust | 1 |
9l6671 Shield Gp-Manifold
| 9L***71 | Shield Group-Manifold; Manifold Shield Group | 1 |
9n5264 Turbocharger Gp*R
| 9N***64 | Turbocharger Group | 1 |
8n4416 Turbocharger Gp
| 8N***16 | Turbocharger Group; Turbocharger Group | 1 |
7c6624 Turbocharger Gp
| 7C***24 | Turbocharger Group | 1 |
7c6615 Turbocharger Gp
| 7C***15 | Turbocharger Group | 1 |
Lubrication System
2n8220 Breather Gp-Crankcase
| 2N***20 | Breather Group; Breather Gp-Crankcase | 1 |
4n2481 Fastener Gp-Oil Pump Mounting
| 4N***81 | Fastener Group-Oil Pump Mounting; Oil Pump Mounting Fastener Group | 1 |
2w7201 Filler Gp-Oil-L.H.
| 2W***01 | Filler Group-Oil | 1 |
4n0731 Filter Gp-Oil
| 4N***31 | Filter Group-Oil; Filter Gp-Engine Oil | 1 |
4n1288 Fumes Disposal Gp
| 4N***88 | Fumes Disposal Group; Fumes Disposal Group | 1 |
4n9951 Gauge Gp-Oil Level-L.H.
| 4N***51 | Gauge Group-Oil Level (Dipstick); Oil Level Gauge Group | 1 |
4n1128 Lines Gp-Engine Oil
| 4N***28 | Lines Group-Engine Oil; Oil Lines Group-Engine | 1 |
7x8889 Circulation Gp-Lubrication-Part 1 Of 2
| 7X***89 | Lubrication Group | 1 |
7x8889 Circulation Gp-Lubrication-Part 2 Of 2
| 7X***89 | Lubrication Group | 1 |
4n0733 Pump Gp-Engine Oil*R
| 4N***33 | Pump Group-Engine Oil | 1 |
0774352 Pump Gp-Hydraulic
| 07***52 | Pump Group-Hydraulic | 1 |
Power Train
7x2191 Axle Ar-Steering Drive
| 7X***15 | Housing Group-Axle | 1 |
| 7X***16 | Differential Group | 1 |
| 7X***42 | Axle Group; Axle Gp-Wheel End | 1 |
7x2142 Axle Gp-Wheel End
| 7X***42 | Axle Group; Axle Gp-Wheel End | 1 |
7x2190 Axle Gp-Drive
| 7X***90 | Axle Group-Drive | 1 |
0775973 Clutch Gp
| 07***73 | Clutch Group-Power Take-Off | 1 |
7x2116 Differential Gp
| 7X***16 | Differential Group | 1 |
7x2115 Housing Gp-Axle
| 7X***15 | Housing Group-Axle | 1 |
0780278 Motor Gp-Hydraulic*R
| 07***78 | Motor Group-Piston | 1 |
7x9170 Propel Gp-Hydrostatic-Part 2 Of 4
| 7X***70 | Propel Group-Hydrostatic | 1 |
7x9170 Propel Gp-Hydrostatic-Part 3 Of 4
| 7X***70 | Propel Group-Hydrostatic | 1 |
7x9170 Propel Gp-Hydrostatic-Part 4 Of 4
| 7X***70 | Propel Group-Hydrostatic | 1 |
7x9170 Propel Gp-Hydrostatic-Part 1 Of 4
| 7X***70 | Propel Group-Hydrostatic | 1 |
7r4901 Pump Gp-Charge
| 7R***01 | Pump Group-Charge | 1 |
7x7438 Pump Gp-Hydraulic*R
| 7X***38 | Pump Group-Hydraulic | 1 |
0780289 Line As-Drive
| 07***89 | Shaft Group-Drive | 1 |
7x8242 Transmission As-Part 1 Of 2
| 7X***42 | Transmission As | 1 |
7x8242 Transmission As-Part 2 Of 2
| 7X***42 | Transmission As | 1 |
7x8314 Wheel & Tire Gp-Front
| 7X***14 | Wheel & Tire Group-Front | 1 |
7x8309 Wheel & Tire Gp-Rear
| 7X***09 | Wheel & Tire Group-Rear | 1 |
Rotor System
0816817 Axle As-Rotor
| 08***17 | Axle As | 1 |
7x2201 Case As-Chain-L.H.-Part 4 Of 5
| 7X***01 | Case As-Chain-Lh | 1 |
7r2908 Case As-Chain-L.H.-Part 2 Of 4
| 7R***08 | Case As-Chain-Lh | 1 |
7x2201 Case As-Chain-L.H.-Part 1 Of 5
| 7X***01 | Case As-Chain-Lh | 1 |
7r2908 Case As-Chain-L.H.-Part 3 Of 4
| 7R***08 | Case As-Chain-Lh | 1 |
7r2908 Case As-Chain-L.H.-Part 4 Of 4
| 7R***08 | Case As-Chain-Lh | 1 |
7r2908 Case As-Chain-L.H.-Part 1 Of 4
| 7R***08 | Case As-Chain-Lh | 1 |
7x2201 Case As-Chain-L.H.-Part 3 Of 5
| 7X***01 | Case As-Chain-Lh | 1 |
7x2201 Case As-Chain-L.H.-Part 2 Of 5
| 7X***01 | Case As-Chain-Lh | 1 |
7x2201 Case As-Chain-L.H.-Part 5 Of 5
| 7X***01 | Case As-Chain-Lh | 1 |
7x2202 Case As-Chain-R.H.-Part 2 Of 5
| 7X***02 | Case As-Chain-Rh | 1 |
7x2202 Case As-Chain-R.H.-Part 1 Of 5
| 7X***02 | Case As-Chain-Rh | 1 |
7r2907 Case As-Chain-R.H.-Part 2 Of 4
| 7R***07 | Case As-Chain-Rh | 1 |
7r2907 Case As-Chain-R.H.-Part 4 Of 4
| 7R***07 | Case As-Chain-Rh | 1 |
7x2202 Case As-Chain-R.H. -Part 3 Of 5
| 7X***02 | Case As-Chain-Rh | 1 |
7r2907 Case As-Chain-R.H.-Part 1 Of 4
| 7R***07 | Case As-Chain-Rh | 1 |
7x2202 Case As-Chain-R.H.-Part 5 Of 5
| 7X***02 | Case As-Chain-Rh | 1 |
7x2202 Case As-Chain-R.H.-Part 4 Of 5
| 7X***02 | Case As-Chain-Rh | 1 |
7r2907 Case As-Chain-R.H.-Part 3 Of 4
| 7R***07 | Case As-Chain-Rh | 1 |
7x8778 Control Gp-Depth-Part 2 Of 2
| 7X***78 | Control Group-Depth | 1 |
7x8778 Control Gp-Depth-Part 1 Of 2
| 7X***78 | Control Group-Depth | 1 |
7x9576 Drive Gp-Rotor-Part 1 Of 2
| 7X***76 | Drive Group-Rotor | 1 |
7x9576 Drive Gp-Rotor-Part 2 Of 2
| 7X***76 | Drive Group-Rotor | 1 |
7x8315 Hood As-Rotor-Part 3 Of 5
| 7X***15 | Hood As-Rotor | 1 |
7x8315 Hood As-Rotor-Part 1 Of 5
| 7X***15 | Hood As-Rotor | 1 |
7x8315 Hood As-Rotor-Part 4 Of 5
| 7X***15 | Hood As-Rotor | 1 |
7x8315 Hood As-Rotor-Part 2 Of 5
| 7X***15 | Hood As-Rotor | 1 |
7x8315 Hood As-Rotor-Part 5 Of 5
| 7X***15 | Hood As-Rotor | 1 |
7x9589 Hood Gp-Rotor-Part 1 Of 5
| 7X***89 | Hood Group-Rotor | 1 |
7x9589 Hood Gp-Rotor-Part 5 Of 5
| 7X***89 | Hood Group-Rotor | 1 |
7x9589 Hood Gp-Rotor-Part 4 Of 5
| 7X***89 | Hood Group-Rotor | 1 |
7x9589 Hood Gp-Rotor-Part 3 Of 5
| 7X***89 | Hood Group-Rotor | 1 |
7x9589 Hood Gp-Rotor-Part 2 Of 5
| 7X***89 | Hood Group-Rotor | 1 |
0774330 Kit-Electric Shift
| 07***30 | Kit-Electric Shift | 1 |
8c0008 Rotor Ar-Chopper
| 8C***08 | Rotor Ar-Chopper | 1 |
8c0009 Rotor As-Part 2 Of 2
| 8C***09 | Rotor As | 1 |
8c0010 Rotor As-Tool
| 8C***10 | Rotor As | 1 |
8c0009 Rotor As-Part 1 Of 2
| 8C***09 | Rotor As | 1 |
0980709 Transmission As
| 09***09 | Transmission Group-Rotor | 1 |
Service Equipment And Supplies
7r0009 Decal & Finish Gp-Part 2 Of 3
| 7R***09 | Film Group | 1 |
7r0009 Decal & Finish Gp-Part 1 Of 3
| 7R***09 | Film Group | 1 |
7r0009 Decal & Finish Gp-Part 3 Of 3
| 7R***09 | Film Group | 1 |
Soil Stabilizer
Ss-250 Soil Stabilizer
| 8C***07 | General Ar | 1 |
Starting And Electrical System
1005047 Alternator Gp-Charging-24 Volt, 50 Ampere*R
| 10***45 | Alternator Group-Charging; (Nippondenso) | 1 |
| 10***46 | Alternator Group-Charging; -24-Volt, 50-Ampere | 1 |
| 10***47 | Alternator Group-Charging; -24-Volt, 50-Ampere | 1 |
9g9538 Alternator Gp
| 9G***38 | Alternator Group-Charging | 1 |
1005046 Alternator Gp-Charging-24 Volt, 50 Ampere
| 10***46 | Alternator Group-Charging; -24-Volt, 50-Ampere | 1 |
6t7223 Alternator Gp
| 6T***23 | Alternator Group-Charging; Alternator Group-Nippondenso -- 24 Volt, 50 Ampere | 1 |
1005045 Alternator Gp-Charging-24 Volt, 50 Ampere
| 10***45 | Alternator Group-Charging; (Nippondenso) | 1 |
5s9088 Alternator Gp*R
| 3T***88 | Alternator Group-Charging; Alternator Group Delco-Remy 24 Volt, 50 Ampere | 1 |
| 5S***88 | Alternator Group-Charging | 1 |
| 6T***23 | Alternator Group-Charging; Alternator Group-Nippondenso -- 24 Volt, 50 Ampere | 1 |
3t1888 Alternator Gp
| 3T***88 | Alternator Group-Charging; Alternator Group Delco-Remy 24 Volt, 50 Ampere | 1 |
5e9573 Electrical Gp-Part 1 Of 2
| 5E***73 | Control Group | 1 |
5e9573 Electrical Gp-Part 2 Of 2
| 5E***73 | Control Group | 1 |
8c0120 Light Ar-Working
| 8C***20 | Lighting Ar-Working | 1 |
5n8757 Magnetic Pickup Gp
| 5N***57 | Magnetic Pickup Group; Magnetic Pick-Up Group | 1 |
7w1340 Mounting Gp-Alternator
| 7W***40 | Mounting Group-Alternator | 1 |
1w6157 Mounting Gp-Alternator
| 1W***57 | Mounting Group-Alternator | 1 |
7x8312 Shunt As
| 7X***12 | Shunt As | 1 |
2w8198 Shut-Off Gp-Electrical
| 2W***98 | Shutoff Group-Electrical; -Fuel | 1 |
2w8198 Shutoff Gp-Electrical
| 2W***98 | Shutoff Group-Electrical; -Fuel | 1 |
Steering
8c9281 Bolster As-Rear
| 8C***81 | Bolster As-Rear | 1 |
7x8779 Steering Gp-Power-Part 1 Of 2
| 7X***79 | Steering Group-Power | 1 |
7x8779 Steering Gp-Power-Part 2 Of 2
| 7X***79 | Steering Group-Power | 1 |
0774160 Valve Gp-Steering
| 07***60 | Valve Group-Steering | 1 |
Water Spray System
5e9998 Control Gp
| 5E***98 | Control Group | 1 |
7r0005 Lines As
| 7R***05 | Lines As | 1 |
7r0004 Lines As
| 7R***04 | Lines As | 1 |
7r0006 Lines As
| 7R***06 | Meter & Lines As-Flow; Lines & Flow Meter As | 1 |
7r0003 Lines & Flow Meter As
| 7R***03 | Meter & Lines As-Flow; Lines & Flow Meter As | 1 |
9n9528 Spray Ar-Water
| 5E***98 | Control Group | 1 |
| 7R***02 | Spray Bar & Pump Group | 1 |
| 7R***05 | Lines As | 1 |
8c9279 Spray Ar-Water
| 5E***98 | Control Group | 1 |
| 7R***02 | Spray Bar & Pump Group | 1 |
| 7R***06 | Meter & Lines As-Flow; Lines & Flow Meter As | 1 |
8c9280 Spray Ar-Water
| 5E***98 | Control Group | 1 |
| 7R***01 | Spray Bar & Pump Group | 1 |
| 7R***03 | Meter & Lines As-Flow; Lines & Flow Meter As | 1 |
9n9529 Spray Ar-Water
| 5E***98 | Control Group | 1 |
| 7R***01 | Spray Bar & Pump Group | 1 |
| 7R***04 | Lines As | 1 |
7r0002 Pump Gp-Bar
| 7R***02 | Spray Bar & Pump Group | 1 |
7r0001 Pump & Spray Bar As
| 7R***01 | Spray Bar & Pump Group | 1 |
SS-250 serial number reference
On these Cat soil stabilizer/road reclaimer units the Product Identification Number (PIN) plate is mounted on the machine frame, commonly on a frame rail or post near the operator's platform/steps, separate from the engine's own serial plate on the block. On the PIN, the first three characters are the serial prefix, tying the unit to a specific model/build series; the digits that follow are the sequential unit number within that prefix. Use the prefix plus serial number to match the correct parts and service manual break, and confirm exact placement with your dealer if the plate is not visible at the frame rail.
| Prefix | Identifies | Notes |
|---|---|---|
| 6DD | SS-250 (base/first-generation Soil Stabilizer) | Base SS-250 machine prefix. Serials 6DD00001-00117 are catalogued with the Cat 3406B engine; from 6DD00118 up, the same prefix is catalogued with the plain Cat 3406 engine - a documented mid-run engine change within one prefix, not a different model. Field units carrying this prefix are dated from 1986 through at least 1990, so the prefix spans the full base-SS-250 production run rather than only the mid-1980s. |
| 5GR | SS-250B (updated Soil Stabilizer) | Prefix for the SS-250B parts catalog and service manual line, distinct from the base 6DD SS-250. The SS-250B uses a Cat 3406 diesel rated around 335 gross hp (metric equivalent approx. 250 kW). Documented units with this prefix date from around 1990-1991, overlapping the tail end of 6DD production. |
Frequently asked questions
What engine does the Caterpillar SS-250 use?
A Caterpillar 3406-series inline-six diesel. The base machine (6DD prefix) carries a 3406B rated near 335 gross hp (250 kW); the SS-250B (5GR prefix) carries a plain 3406 rated at the same 335 gross hp per factory literature. Higher-output figures near 430 hp (3406C DITA) turn up in some secondary listings but aren't confirmed for this chassis, so confirm the engine tag on any specific serial number.
What is the operating weight of the SS-250?
Operating weight varies by configuration, ballast, and rotor fitted, ranging roughly from 12,900 to 16,000 kg (28,500 to 35,200 lb) across documented units. Always verify against the specific machine's rotor and equipment package rather than assuming a single figure.
What replaced the Caterpillar SS-250?
Caterpillar carried the platform forward as the SS-250B and RR-250B, which shared service parts with the RM-350B and RM-250C reclaimers into the late 1990s and 2000s. Caterpillar then replaced the entire mechanical platform with its modern electronically controlled RM-series Rotary Mixers, starting with the RM300 and RM500 and later the RM500B.
What SS-250 owners discuss
What engine does the Cat SS-250 actually run, and why do listings show different horsepower numbers?
Base SS-250 units (6DD prefix) run a Cat 3406B inline-six rated around 335 gross hp (250 kW). The updated SS-250B (5GR prefix) carries a Cat 3406 rated at the same 335 gross hp per factory literature. A 430 hp 3406C DITA figure turns up in some secondary listings, but it isn't confirmed for this chassis and may reflect a different reclaimer model - confirm the exact engine tag on the serial plate before ordering major engine parts or comparing output to another owner's machine.
Mechanical 3406B vs electronically controlled 3406C on this platform - does it change how the engine behaves?
Yes. The 3406B here uses a mechanical unit-injection fuel system with a jake-style governor and fuel rack linkage - straightforward to diagnose with a pressure gauge, but slow throttle response or rough idle after any fuel-system work usually traces back to a sticking rack or a linkage that's out of adjustment. Machines built with the PEEC-style electronically controlled 3406C add an ECM, timing/rack solenoid, and engine speed sensor into the mix; owners of that engine family across other applications report surging or intermittent power loss when those components or their wiring degrade with age. If you're chasing an intermittent power or surge complaint on a PEEC-equipped unit, have your dealer verify the ECM and speed-sensor wiring before replacing fuel system parts.
What wears out first on the rotor and its drive?
The cutting bits and bit holders on the rotor take the brunt of the abuse and wear rate depends heavily on the material being reclaimed - asphalt with a lot of aggregate chews through carbide bits far faster than a soft soil-cement job. Worn or damaged cast bit holders can be cut off and replaced with weld-on holders rather than swapping the whole rotor. The rotor drive itself is a heavy chain-and-clutch setup; the chain is self-lubricating and isn't meant to need routine adjustment, so persistent chain slack, clutch slip, or chain noise is a sign something upstream (bearing, sprocket, or clutch wear) needs a proper inspection rather than a quick tension fix.
Any known differences between early and later serial-numbered machines?
Yes - Caterpillar increased the rated rotor drive chain capacity on production from roughly serial number 6DD00070 onward. If you're pricing a chain or drive component for an early-build machine, don't assume it interchanges with a later one without checking the serial break; the drivetrain load rating differs across that production change.
What should I expect from the drivetrain and tires day to day?
The SS-250 is an all-wheel-drive rubber-tired machine, not a tracked undercarriage, and many were built with solid cushion tires rather than pneumatics given the low-speed, high-torque application. Expect tire/cushion wear and cracking to be the main wear item in place of an undercarriage, rather than track pads or rollers - inspect the cushion rubber for chunking and check wheel-end seals for leaks, since these machines spend most of their life crawling through abrasive reclaimed material at walking speed.
The water spray system keeps clogging or applying uneven moisture - what's going on?
This is a generic spray-system wear issue rather than an SS-250-specific defect: reclaimed base material and job-site water sources carry sand, silt, and mineral content that plug nozzle orifices over time. Owners dealing with inconsistent spray patterns on similar mixing/stabilizing equipment generally trace it to nozzle wear, a dirty inline filter ahead of the spray bar, or mineral buildup rather than a pump failure. Regular nozzle inspection and filtration ahead of the spray manifold prevents most of it; if the spray bar won't calibrate correctly even with clean nozzles, have your dealer verify the metering/flow-control circuit before assuming a pump problem.
What should I check before buying a used SS-250?
Weigh hours against age and job history - a machine that mostly ran soil-cement will show far less rotor and bit wear than one that spent its life chewing old asphalt. Pull the side access doors and inspect the rotor bits, bit holders, and end rings directly rather than trusting a seller's description. Confirm which engine is actually installed (mechanical 3406B vs electronically controlled 3406C DITA) since that changes both the power rating and how you'll diagnose future issues. Check the rotor drive chain and clutch for slack, slip, or unusual noise under load, inspect tires/cushions for chunking, and run the water spray system through a calibration check. Verify hydraulic response on all functions is crisp with no lag, and confirm the machine's serial number to know which production-run drivetrain rating it carries. For anything involving the fuel system, ECM wiring, or rotor clutch adjustment, have your dealer verify before you finalize the purchase price.
Compiled from owner and technician discussions across the industry — experiences vary by serial range and machine history.
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