Caterpillarwork tooltrencher

Caterpillar T15

Maintenance schedule, common problems & OEM parts breakdown

The Caterpillar T15 is a passive, hydraulically driven trencher work tool built around a 1524 mm (60 in) boom class, one of the larger sizes in Cat's compact-trencher range. It has no engine, no ECM and no fuel or cooling system of its own; every bit of digging power comes from the carrier machine, and its weight and output shift with the digging chain and tooth package fitted rather than with any engine rating. It mounts through a universal quick-attach face to skid steer loaders, compact track loaders, multi-terrain loaders, backhoe loaders and compact wheel loaders, driving its chain off the carrier's auxiliary hydraulic circuit through a gerotor-style drive motor feeding a reduction drivetrain inside the boom. Serial prefix ABL identifies this base T15, and it predates the direct-drive T15B that followed it, offered over its run with a choice of digging chains for different soil types and with manual or hydraulic side-shift.

Cat's follow-on T15B dropped the internal reduction stage in favor of a direct-coupled, variable-speed, bi-directional gerotor motor bolted straight to the sprocket shaft, trading a mechanical reduction stage for fewer wear points and tighter chain-speed control. That direct-drive layout carried on into today's Cat trencher line, where the same 60 in boom class continues under a later model designation. For the used and parts market, the base T15 matters mainly as an interchange source for boom, chain, sprocket and wear-bar components sized to the same 60 in class, plus the quick-attach mounting hardware that keeps these tools working on older skid steer and backhoe loader fleets long after Cat stopped selling the model new. With no engine or electronics to fail, surviving units are typically retired by structural fatigue, chain-case wear or a worn-out drive motor rather than obsolescence, which keeps sound examples and their teardown parts in steady demand.

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 T15 specifications

Engine

Power source	No onboard engine. The T15 is a passive trencher work tool driven entirely by the carrier machine's hydraulic system, through a variable-speed, bi-directional gerotor-style drive motor mounted on the trencher frame.
Motor displacement	Not separately published for the original ABL-prefix T15. The direct-drive successor design (60 in / 1524 mm boom trencher, now sold as part of the B-Series/T315 line) lists 629.1 cm3/rev (38.4 in3/rev) — reference only, not confirmed for the original T15.
Emissions tier	Not applicable. This work tool carries no combustion engine of its own.

Weights

Unit weight

Not independently published for the original T15. The direct-drive successor trencher in the same 60 in boom, double-standard chain, 8 in cut configuration lists 601 kg (1,325 lb) as tested — treat as a reference point only and confirm the exact figure with your dealer for an ABL-prefix unit.

Dimensions

Standard boom length	Original T15 boom length not confirmed from an independent factory spec sheet. The successor direct-drive trencher built on this size class uses a 1524 mm (60 in) boom — reference only.
Overall width	Not confirmed for the original T15. Successor unit in this size class: 1901 mm (74.8 in) — reference only.
Overall length	Not confirmed for the original T15. Successor unit in this size class: 3010 mm (118.5 in) — reference only.
Overall height	Not confirmed for the original T15. Successor unit in this size class: 786 mm (30.9 in) — reference only.
Side-shift travel	Not confirmed for the original T15. Successor unit offers up to 559 mm (22 in) of side shift — reference only.
Spoil auger diameter	Not confirmed for the original T15. Successor unit: 457 mm (18 in) — reference only.
Max auger clearance	Not confirmed for the original T15. Successor unit: 534 mm (21 in) — reference only.

Performance

Carrier / host machine class	Factory parts documentation ties the original T15 trencher to a size class matched with a T9 trencher sibling (no B suffix), for smaller loaders and backhoes of that era. Requires the carrier's high-flow auxiliary hydraulic circuit.
Required hydraulic flow range	Not confirmed for the original T15. Successor unit in this size class needs 95 to 152 L/min (25 to 40 gpm) — reference only, varies by carrier and configuration.
Optimal hydraulic pressure range	Not confirmed for the original T15. Successor unit: 207 to 310 bar (3,000 to 4,500 psi), with a maximum rated pressure of 290 bar (4,205 psi) — reference only.
Theoretical drive shaft torque	Not confirmed for the original T15. Successor unit: 2905 N.m (2,144 lb-ft) — reference only.
Chain pull at max pressure	Not confirmed for the original T15. Successor unit: 2424 kg (5,344 lb) — reference only.
Chain speed at max flow	Not confirmed for the original T15. Successor unit: 158 m/min (518 ft/min) — reference only.
Drive shaft speed at max flow	Not confirmed for the original T15. Successor unit: about 207 rpm at 129 L/min (34 gpm) — reference only.
Optional cutting widths	Chain and cutting-width options on the trencher line span roughly 152 to 305 mm (6 to 12 in), offered across multiple chain styles (standard, combo, terminator, rock-frost) for different soil conditions — not confirmed which subset applied to the original T15 specifically.

Service capacities (summary)

Fuel tank	Not applicable — the work tool has no fuel system; it runs off the carrier machine.
Hydraulic system	No dedicated reservoir on the work tool itself. It draws hydraulic flow directly from the carrier machine's auxiliary circuit — see Performance group for flow and pressure ranges.
Engine oil	Not applicable — no engine on the work tool.
Cooling system	Not applicable — heat rejection is handled through the carrier machine's hydraulic system.

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

T15 fluids & capacities

System	Capacity	Recommended fluid
Engine crankcase (with filter)	Not applicable	The T15 has no engine of its own. It is a passive digging-chain work tool mounted on a skid steer loader, compact track loader, or mini excavator, driven entirely by the carrier machine's auxiliary hydraulic circuit.
Cooling system	Not applicable	No radiator or coolant circuit on the work tool. Cooling is handled by the host carrier machine's own system.
Fuel tank	Not applicable	No fuel tank. The attachment carries no combustion engine.
Transmission / powertrain compartment	Not applicable	No transmission or powershift compartment on the attachment. Digging chain speed is set directly by the carrier's auxiliary hydraulic flow to the trencher's hydraulic drive motor.
Final drives (each)	Not applicable	No final drive housings. The chain sprocket is driven straight off the integral hydraulic motor; there is no gearbox oil sump documented for this attachment.
Hydraulic system and tank	No dedicated reservoir on the attachment. Family literature for this trencher line calls for standard-flow auxiliary hydraulics in the low-to-mid teens gpm range on the base/A-series unit, with the later high-flow chain and boom variants needing roughly 95 to 152 L/min (25 to 40 US gpm) at up to about 290 bar (4,205 psi), all supplied by the carrier machine's own hydraulic tank	Runs on whatever hydraulic oil the host skid steer, track loader, or excavator already carries (typically Cat HYDO Advanced or the machine-specific hydraulic fluid called out in that carrier's own OMM). The trencher itself specifies no separate fluid brand or viscosity grade — match the host machine's chart.
Axles / differentials	Not applicable	No axles or differentials. The unit has no wheels or drive axles of its own; it rides on the carrier's quick-coupler frame.
Grease (spec only)	No fluid capacity figure published; lube per the interval chart, not by volume	Multipurpose chassis grease at the boom pivot, side-shift slide, idler and drive-sprocket bearings, per Cat's general work-tool lubrication convention (Cat Multipurpose Grease or Cat Advanced 3Moly Grease, NLGI 2). No climate-based viscosity split is published for this attachment the way there is for engine or hydraulic oil.

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

Caterpillar T15 maintenance schedule

Service interval	Tasks
Every 50 h	Daily: clean mud and debris off the chain, sprockets and boom before and after each shift Daily: inspect digging teeth for wear, cracks or missing carbide inserts; replace as a matched set to keep the chain balanced Daily: check digging-chain tension and adjust to the boom-sag spec before resuming work Weekly (50 hr): grease the boom pivot pins, idler bearings and quick-attach mounting points Weekly (50 hr): inspect wear bars on the boom rails for grooving cut by the chain side plates Weekly (50 hr): check the carrier's auxiliary hydraulic hoses and quick-couplers for leaks, chafing or swelling
Every 250 h	Rotate or replace the drive sprocket if teeth show scalloped wear, even if the chain still looks serviceable Inspect digging-chain rollers for beveled grooves and replace the chain before it damages the sprocket Check the gerotor drive motor's shaft seal and mounting bolts for hydraulic seepage or looseness Verify the carrier's hydraulic flow and pressure output still matches this trencher's rating before resuming heavy digging
Every 500 h	Open the reduction drivetrain case inside the boom and inspect the internal gearing or chain for wear Drain and renew the chain-case gear lubricant; check the drain plug for metal fines Inspect boom-to-mainframe pivot bushings and pins for play; shim or replace as needed Bench-check the drive motor circuit relief setting against the OMM chart
Every 1,000 h	Pull the drive sprocket and idler shaft bearings and measure wear against service limits Inspect the boom structure and wear-bar welds for cracking from cumulative shock loads Replace the gerotor motor shaft seal as a preventive measure regardless of visible leakage Re-torque all mounting bracket and quick-attach fasteners to spec
Every 2,000 h	Overhaul or exchange the gerotor drive motor if flow and pressure tests fall below new-unit performance Replace the reduction drivetrain's chain, sprockets and bearings as a matched set Inspect the full boom weldment for fatigue cracking, especially around pivot bosses and idler mounts Have the carrier's own auxiliary hydraulic circuit flow-checked; a tired carrier pump can masquerade as trencher wear
Every 4,000 h	Strip the boom assembly and replace all wear bars, idler wheels and pivot bushings regardless of measured wear Decide whether the chain case and gerotor motor get a full rebuild or an exchange unit Have the mainframe and quick-attach mounting plate crack-checked before returning the tool to service Weigh true rebuild cost against current used-parts market value before committing to a full overhaul

Servicing the T15 beyond the schedule

Predictive Maintenance & Fluid Analysis

Because the T15 has no engine or hydraulic reservoir of its own, predictive care means watching the carrier's hydraulic oil. Pull samples from the carrier tank on schedule; metal fines or varnish there often trace back to a worn gerotor drive motor or a failing shaft seal in the trencher, not the carrier itself. Sample the reduction chain-case gear lubricant separately at drain intervals and watch for bright metal or chain-pitch particles, an early flag that the sprocket or reduction gearing is fatiguing before it fails in the field.

Corrective & Common Repairs

Most T15 callbacks trace to the digging chain, the wear bars and the drive motor seal. A stretched or derailed chain and wear bars grooved by the chain's side plates account for the bulk of them. Replace wear bars before the groove reaches the rail steel, not after, and always swap the drive sprocket alongside a new chain rather than mating fresh chain to a scalloped sprocket. Check the quick-attach wedge and pins for play too; a loose mount accelerates every other wear point on the boom.

Overhaul & Rebuild Points

A full T15 rebuild centers on the reduction drivetrain inside the boom: open the chain case, measure the internal gearing or chain and sprockets against service limits, and renew the set together rather than piecemeal. Inspect the boom weldment around the pivot bosses and idler mounts for fatigue cracking, since cumulative shock loads from rock and root strikes concentrate there. Decide early whether the gerotor drive motor gets rebuilt or exchanged; on a tool this age, sourcing a sound used motor often beats a reseal-and-hope repair.

Seasonal & Environment Servicing

Cold ground stiffens chain lubricant and shrinks steel, so recheck chain tension after the first hard freeze and step up to a rock-frost or combo chain if the dig program moves into frozen or rocky ground. Before winter layup, relieve residual pressure at the carrier's auxiliary couplers, cap the hose ends, and grease every boom pivot and idler point to keep moisture out. In wet clay season, wash the chain and wear bars each shift; packed mud turns abrasive and eats wear-bar life fast.

T15 attachments & work tools

Machine type and mounting class

The T15 is itself a hydraulic trencher work tool, not a host machine. It mounts on Cat skid steer loaders, compact track loaders, multi-terrain loaders, and compact wheel loaders as the largest member of the compact trencher family alongside the T6 and T9. It carries its own serial identity separate from the host carrier.

Boom and digging capacity

The T15 uses a 1524 mm (60 in) boom and digs to a maximum depth of about 1524 mm (60 in). Maximum trench width capability with side-shift travel runs up to roughly 300 mm (12 in), though the fitted chain sets the actual cut width.

Digging chain options

Factory chain choices for this size class include standard cup-tooth chain and a rock-rated chain for harder ground, with documented cutting widths as narrow as about 150 mm (6 in) on the 60 in boom. Exact width and tooth pattern are set at order to match soil conditions; confirm the fitted chain code with your dealer since options vary by build.

Drive system

The chain is direct-driven by a bidirectional, variable-speed gerotor-style hydraulic motor fed from the host machine's auxiliary circuit — there is no separate onboard engine. This is a shared design trait across the T6/T9/T15 trencher line.

Hydraulic flow and pressure requirement

Trenchers in this family are documented across a standard-flow band of about 42-86 L/min (11-23 gpm) at 145-235 bar (2,100-3,400 psi), with a high-flow variant at 95-152 L/min (25-40 gpm) and 207-310 bar (3,000-4,500 psi). The T15, being the largest chain-width unit, sits toward the higher end of this range and generally needs a high-flow-equipped carrier; verify the exact spec plate figures for a given build.

Side-shift configuration

This trencher class is offered with hydraulic or manual side-shift carriages, letting the operator slide the boom sideways for close-in trenching along walls, fences, and curbs without repositioning the host machine.

Mounting and coupler system

The T15 attaches through a universal skid-steer quick-attach mounting plate that engages the host machine's loader arms and pin (or powered hydraulic) quick coupler, allowing cab-controlled work-tool swaps without leaving the seat.

Chain guarding and depth control

A shielded boom track and skid shoes run along the digging chain to guide depth and shield the rotating chain from the operator side, standard practice across this trencher class rather than an extra-cost option.

Generation and family notes

The base T15 is the predecessor generation to the later T15B (grouped in factory literature with the T6B and T9B under a shared operation manual), which in turn was succeeded by Cat's current T1xx/T3xx trencher numbering. Treat T15 and T15B as separate generations for exact pressure and chain-width figures — they are documented separately and specs should not be swapped between them.

All T15 assemblies by section

Every catalogued assembly group for the Caterpillar T15. Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.

Frame And Body

179-6319 Frame Gp-Chain Roller

16***89	Screw	1
17***19	Frame Group-Chain Roller	1
17***26	Support As	1
17***27	Arm As-Chain Roller; (60-In)	1

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179-6318 Frame Gp-Trencher

02***87	Fitting-Grease; (Universal Joint)	2
16***75	Frame As	1
16***76	Pin	1
16***77	Bar As	2

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Hydraulic System

147-6781 Cylinder Gp-Hydraulic

00***14	Ring-Retaining; (Internal)	1
14***81	Cylinder Group-Hydraulic	1
16***77	Kit-Seal	1

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179-6329 Lines Gp-Connecting

14***17	Adapter, -12 Orb / -16 Orfs	4
14***18	Connector As	1
14***19	Connector As	2
14***36	Adapter; (Straight) (-6 Orb X -6 Orfs)	3

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179-6322 Motor Gp-Gerotor

17***22	Motor Group-Gerotor	1
19***34	Key	1
19***35	Kit-Seal	1

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Service Equipment And Supplies

189-0703 Plate & Film Gp

15***15	Plate-Identification	1
15***17	Film-Warning; (Entanglement Hazard, Stay Back)(Auger)	1
15***35	Film-Warning; (Crush Hazard, Stay Back)	1
15***36	Film-Warning; (Read Operation Manual)	1

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Work Tool Arrangement

222-7911 Trencher Ar -60-In, Hyd Sishf, High Flow

22***11	Trencher Ar; -60-In, Hydraulic Sishf, High Flow	1
22***23	Chain Group-Trencher; -60-In, 8-In Cut, Standard	1
22***20	Trencher Ar; -60-In, Hydraulic Sishf, High Flow	1

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179-6314 Trencher Ar -60-In Hyd Sishf, 6-In Std Chain, High Flow

14***81	Cylinder Group-Hydraulic	1
17***14	Trencher Ar; -60-In Hydraulic Sishf, 6-In Std Chain, High Flow	1
17***17	Drive Group-Trencher	1
17***18	Frame Group-Trencher	1

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222-8620 Trencher Ar -60-In, Hyd Sishf, High Flow

14***81	Cylinder Group-Hydraulic	1
17***17	Drive Group-Trencher	1
17***18	Frame Group-Trencher	1
17***19	Frame Group-Chain Roller	1

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222-8557 Trencher Ar -60-In, Hyd Sishf, High Flow

22***47	Chain Group-Trencher; -60-In, 6-In Cut, Hard Soil	1
22***57	Trencher Ar; -60-In, Hydraulic Sishf, High Flow	1
22***20	Trencher Ar; -60-In, Hydraulic Sishf, High Flow	1

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Work Tools

166-0788 Arm As-Chain Roller

16***88

Arm As-Chain Roller

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264-7602 Blade Gp-Tool Bar -60-In,Crumber

26***12	Scraper As; (Trencher)	1
26***16	Plate	4
26***00	Support As	1
26***02	Blade Group-Tool Bar; -60-In,Crumber	1

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166-0773 Blade Gp-Tool Bar -48-In, Crumber

16***73	Blade Group-Tool Bar; -48-In, Crumber	1
16***79	Tube	1
16***80	Scraper As	1
16***82	Plate	4

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179-6313 Blade Gp-Tool Bar -60-In, Crumber

16***80	Scraper As	1
16***82	Plate	4
16***99	Plate	1
16***16	Support As	1

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208-2694 Chain Gp-Trencher -48-In, 8-In Cut, Hard Soil

16***08	Chain Group-Trencher; -48-In	1
20***94	Chain Group-Trencher; -48-In, 8-In Cut, Hard Soil	1
20***84	Tooth Group-Trencher; -8-In Hard Soil, 48-In Chain	1

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208-2675 Chain Gp-Trencher -48-In, 8-In Cut, Standard

16***08	Chain Group-Trencher; -48-In	1
19***81	Tooth Group-Trencher; -8-In Standard, 48-In Chain	1
20***75	Chain Group-Trencher; -48-In, 8-In Cut, Standard	1

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208-2699 Chain Gp-Trencher -60-In, 8-In Cut, Hard Soil

17***16	Chain Group-Trencher; -60-In	1
20***99	Chain Group-Trencher; -60-In, 8-In Cut, Hard Soil	1
20***94	Tooth Group-Trencher; -8-In Hard Soil, 60-In Chain	1

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222-7747 Chain Gp-Trencher -60-In, 6-In Cut, Hard Soil

17***16	Chain Group-Trencher; -60-In	1
20***91	Tooth Group-Trencher; -6-In Hard Soil, 60-In Chain	1
22***47	Chain Group-Trencher; -60-In, 6-In Cut, Hard Soil	1

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208-2697 Chain Gp-Trencher -60-In, 6-In Cut, Rock

17***16	Chain Group-Trencher; -60-In	1
20***97	Chain Group-Trencher; -60-In, 6-In Cut, Rock	1
20***92	Tooth Group-Trencher; -6-In Rock, 60-In Chain	1

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179-6316 Chain Gp-Trencher -60-In

16***10	Pin	1
17***16	Chain Group-Trencher; -60-In	1
17***21	Chain As	1
18***58	Pin	1

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199-6198 Chain Gp-Trencher -60-In, 6-In Cut, Standard

17***16	Chain Group-Trencher; -60-In	1
18***02	Tooth Group-Trencher; -6-In Standard, 60-In Chain	1
19***98	Chain Group-Trencher; -60-In, 6-In Cut, Standard	1

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166-0808 Chain Gp-Trencher -48-In

16***08	Chain Group-Trencher; -48-In	1
16***09	Chain As	1
16***10	Pin	1
18***58	Pin	1

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208-2698 Chain Gp-Trencher -60-In, 8-In Cut, Rock

17***16	Chain Group-Trencher; -60-In	1
20***98	Chain Group-Trencher; -60-In, 8-In Cut, Rock	1
20***93	Tooth Group-Trencher; -8-In Rock, 60-In Chain	1

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208-2695 Chain Gp-Trencher -60-In, 6-In Cut, Rock

17***16	Chain Group-Trencher; -60-In	1
20***95	Chain Group-Trencher; -60-In, 6-In Cut, Rock	1
20***90	Tooth Group-Trencher; -6-In Rock, 60-In Chain	1

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208-2677 Chain Gp-Trencher -60-In, 8-In Cut, Standard

17***16	Chain Group-Trencher; -60-In	1
19***27	Tooth Group-Trencher; -8-In Standard, 60-In Chain	1
20***77	Chain Group-Trencher; -60-In, 8-In Cut, Standard	1

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208-2678 Chain Gp-Trencher -48-In, 10-In Cut, Standard

16***08	Chain Group-Trencher; -48-In	1
19***82	Tooth Group-Trencher; -10-In Standard, 48-In Chain	1
20***78	Chain Group-Trencher; -48-In, 10-In Cut, Standard	1

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208-2692 Chain Gp-Trencher -48-In, 6-In Cut, Rock

16***08	Chain Group-Trencher; -48-In	1
20***92	Chain Group-Trencher; -48-In, 6-In Cut, Rock	1
20***82	Tooth Group-Trencher; -6-In Rock, 48-In Chain	1

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189-5957 Chain Gp-Trencher -60-In, 6-In Cut, Standard

17***16	Chain Group-Trencher; -60-In	1
18***02	Tooth Group-Trencher; -6-In Standard, 60-In Chain	1
18***57	Chain Group-Trencher; -60-In, 6-In Cut, Standard	1

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208-2679 Chain Gp-Trencher -60-In, 10-In Cut, Standard

17***16	Chain Group-Trencher; -60-In	1
19***28	Tooth Group-Trencher; -10-In Standard, 60-In Chain	1
20***79	Chain Group-Trencher; -60-In, 10-In Cut, Standard	1

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208-2690 Chain Gp-Trencher -48-In, 6-In Cut, Rock

16***08	Chain Group-Trencher; -48-In	1
20***90	Chain Group-Trencher; -48-In, 6-In Cut, Rock	1
20***80	Tooth Group-Trencher; -6-In Rock, 48-In Chain	1

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222-8523 Chain Gp-Trencher -60-In, 8-In Cut, Standard

17***16	Chain Group-Trencher; -60-In	1
19***27	Tooth Group-Trencher; -8-In Standard, 60-In Chain	1
22***23	Chain Group-Trencher; -60-In, 8-In Cut, Standard	1

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208-2691 Chain Gp-Trencher -48-In, 6-In Cut, Hard Soil

16***08	Chain Group-Trencher; -48-In	1
20***91	Chain Group-Trencher; -48-In, 6-In Cut, Hard Soil	1
20***81	Tooth Group-Trencher; -6-In Hard Soil, 48-In Chain	1

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208-2693 Chain Gp-Trencher -48-In, 8-In Cut, Rock

16***08	Chain Group-Trencher; -48-In	1
20***93	Chain Group-Trencher; -48-In, 8-In Cut, Rock	1
20***83	Tooth Group-Trencher; -8-In Rock, 48-In Chain	1

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179-6317 Drive Gp-Trencher

00***12	Cup-Roller Bearing	2
16***98	Hub	1
16***03	Auger	1
17***17	Drive Group-Trencher	1

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179-6320 Idler Gp-Chain

02***87	Fitting-Grease; (Universal Joint)	1
11***48	Nut; (M30x1.5-Thd)	1
16***92	Spacer; (Bearing)(10.41mm Thk)	2
16***93	Seal	2

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208-2793 Tooth Gp-Trencher -8-In Rock, 60-In Chain

16***25	Tooth; (Lh)	15
16***26	Tooth; (Rh)	15
19***23	Bracket; (8-In Cut)(8 In)	6
19***26	Bracket; (6.5-In Cut)(6.5 In)	6

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208-2782 Tooth Gp-Trencher -6-In Rock, 48-In Chain

20***81	Spacer; (13.9x21.3x26.4-mm Thk)	32
20***83	Spacer; (13.9x21.3x46-mm Thk)	40
20***84	Holder-Bit; (Lh)(Center)	15
20***85	Holder-Bit; (Rh)(Center)	15

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195-3900 Tooth Gp-Trencher -12-In Standard, 48-In Chain

16***25	Tooth; (Lh)	28
16***26	Tooth; (Rh)	28
19***23	Bracket; (8-In Cut)(8 In)	5
19***24	Bracket; (10-In Cut)(10 In Cut)	5

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208-2783 Tooth Gp-Trencher -8-In Rock, 48-In Chain

16***25	Tooth; (Lh)	12
16***26	Tooth; (Rh)	12
19***23	Bracket; (8-In Cut)(8 In)	4
19***26	Bracket; (6.5-In Cut)(6.5 In)	4

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208-2790 Tooth Gp-Trencher -6-In Rock, 60-In Chain

16***25	Tooth; (Lh)	13
16***26	Tooth; (Rh)	13
19***26	Bracket; (6.5-In Cut)(6.5 In)	6
20***81	Spacer; (13.9x21.3x26.4-mm Thk)	16

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208-2791 Tooth Gp-Trencher -6-In Hard Soil, 60-In Chain

16***25	Tooth; (Lh)	13
16***26	Tooth; (Rh)	13
19***21	Tooth; (Lh)	3
19***22	Tooth; (Rh)	3

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194-4681 Tooth Gp-Trencher -8-In Standard, 48-In Chain

16***25	Tooth; (Lh)	25
16***26	Tooth; (Rh)	25
19***23	Bracket; (8-In Cut)(8 In)	7
19***26	Bracket; (6.5-In Cut)(6.5 In)	14

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193-5729 Tooth Gp-Trencher

16***25	Tooth; (Lh)	33
16***26	Tooth; (Rh)	33
19***23	Bracket; (8-In Cut)(8 In)	6
19***24	Bracket; (10-In Cut)(10 In Cut)	6

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208-2781 Tooth Gp-Trencher -6-In Hard Soil, 48-In Chain

16***25	Tooth; (Lh)	12
16***26	Tooth; (Rh)	12
19***21	Tooth; (Lh)	3
19***22	Tooth; (Rh)	3

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194-4682 Tooth Gp-Trencher -10-In Standard, 48-In Chain

16***25	Tooth; (Lh)	27
16***26	Tooth; (Rh)	27
19***23	Bracket; (8-In Cut)(8 In)	6
19***24	Bracket; (10-In Cut)(10 In Cut)	6

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208-2784 Tooth Gp-Trencher -8-In Hard Soil, 48-In Chain

16***25	Tooth; (Lh)	12
16***26	Tooth; (Rh)	12
19***21	Tooth; (Lh)	4
19***22	Tooth; (Rh)	4

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193-5727 Tooth Gp-Trencher -8-In Standard, 60-In Chain

16***25	Tooth; (Lh)	29
16***26	Tooth; (Rh)	29
19***23	Bracket; (8-In Cut)(8 In)	8
19***26	Bracket; (6.5-In Cut)(6.5 In)	16

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189-0702 Tooth Gp-Trencher -6-In Standard, 60-In Chain

16***25	Tooth; (Lh)	11
16***26	Tooth; (Rh)	10
18***02	Tooth Group-Trencher; -6-In Standard, 60-In Chain	1
6V***87	Locknut; (M12x1.75-Thd)	42

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193-5728 Tooth Gp-Trencher -10-In Standard, 60-In Chain

16***25	Tooth; (Lh)	31
16***26	Tooth; (Rh)	32
19***23	Bracket; (8-In Cut)(8 In)	7
19***24	Bracket; (10-In Cut)(10 In Cut)	7

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208-2792 Tooth Gp-Trencher -6-In Rock, 60-In Chain

20***81	Spacer; (13.9x21.3x26.4-mm Thk)	36
20***83	Spacer; (13.9x21.3x46-mm Thk)	48
20***84	Holder-Bit; (Lh)(Center)	17
20***85	Holder-Bit; (Rh)(Center)	17

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208-2794 Tooth Gp-Trencher -8-In Hard Soil, 60-In Chain

16***25	Tooth; (Lh)	15
16***26	Tooth; (Rh)	15
19***21	Tooth; (Lh)	6
19***22	Tooth; (Rh)	6

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208-2780 Tooth Gp-Trencher -6-In Rock, 48-In Chain

16***25	Tooth; (Lh)	12
16***26	Tooth; (Rh)	12
19***26	Bracket; (6.5-In Cut)(6.5 In)	6
20***81	Spacer; (13.9x21.3x26.4-mm Thk)	12

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T15 serial number reference

The PIN/serial tag on a Cat T15 or T15B trencher is riveted to the attachment frame or mounting plate near the hydraulic hose connections at the rear of the boom, not on the host machine. Read it as a 3-letter prefix followed by a numeric sequence (e.g. SLW00001); the prefix identifies the specific trencher model and its parts/manual set, while the sequence number pins down the individual unit within that run.

Prefix	Identifies	Notes
ABL	T15 (base/predecessor chain trencher, pre-B generation)	Earlier Cat T15 chain trencher work tool, ahead of the later T15B update. Serial range starts ABL1 and up. Passive hydraulically driven attachment with no engine of its own; runs off the host carrier's hydraulic system. Confirm exact production years with your dealer.
SLW	T15B chain trencher (current/updated generation)	T15B is the updated trencher in the same digging-depth class as the base T15, fitted to compact track loaders, skid steers, compact wheel loaders and backhoe loaders. Serial range starts SLW00001 and up. Shares a combined parts/manual set with the T9B and T6B siblings, but SLW is specific to the T15B unit, not its T6B or T9B counterparts. Passive attachment; hydraulic motor drives the chain, no ECM or engine.

Frequently asked questions

What engine does the Caterpillar T15 trencher use?

None. The T15 is a passive work tool with no engine, ECM, fuel system or cooling system of its own. It drives its digging chain with a gerotor-style hydraulic motor powered entirely by the carrier machine's auxiliary hydraulic circuit, so its performance depends on the flow and pressure the host skid steer, track loader or backhoe loader can supply.

What does the Caterpillar T15 trencher weigh?

There is no single fixed operating weight; it shifts with the digging chain, tooth package and side-shift option fitted, all built around the same 1524 mm (60 in) boom-class housing. Treat any single weight figure for this class as a starting point rather than a spec-plate number, and confirm the exact figure for your unit against its own nameplate or parts book.

What replaced the Caterpillar T15 trencher?

The direct-drive T15B superseded it, replacing the T15's internal reduction drivetrain with a variable-speed, bi-directional gerotor motor coupled straight to the sprocket shaft. That direct-drive layout carried forward into Cat's current compact trencher line, where the same 60 in boom class continues today under a later model designation.

What T15 owners discuss

How does the T15's hydraulic drive actually work, and what should I know about matching it to my carrier?

The T15 turns its digging chain with a bi-directional gerotor motor mounted at the boom head - there is no gearbox and no engine on the tool itself. Chain speed and torque come entirely from the flow and pressure the carrier's auxiliary circuit supplies, so a standard-flow loader will bog the chain down in anything but soft ground. Across owners of this Cat trencher family, flow mismatch - not the motor itself - is behind most complaints: slow cutting, stalling under load, and extra heat building in the carrier's hydraulic system. Confirm the carrier is rated for the higher auxiliary flow this tool is built around before running it hard. Have your dealer verify your specific carrier's flow and pressure output matches the trencher's rated range before first use.

What wears out first on the chain and boom, and how do I know it needs attention?

The pattern is consistent across Cat and competitor trenchers this size: cupped/carbide teeth dull first, then the chain itself stretches as pins and bushings wear, and finally the drive and idler sprockets thin out from riding a worn chain. Field practice is to stop and eyeball the chain every 8 to 15 m (25 to 50 ft) of cutting in rocky ground, and replace a chain once it can't be adjusted back to spec or the rollers look chewed down to the pin. The boom wear strip on the underside takes the sliding load - replace it before it wears through, because letting it go means machining or replacing the boom body itself, a much bigger job than a strip swap.

How much slack should the chain have, and what happens if it's set wrong?

The consistent target is roughly 38 to 50 mm (1.5 to 2 in) of sag away from the underside of the boom. Too tight accelerates wear on the drive sprocket and boom tip and can overload the drive shaft when packed soil tightens the chain underground; too loose lets the chain slap, jump the idler, or walk off the sprocket. Recheck tension often on a new or reconditioned chain - it seats in quickly during the first few hours of use. If you're not sure what's correct for your serial range, have your dealer verify tension and adjustment procedure before running it under load.

The T15 doesn't have its own engine - where do the drive-related complaints actually come from?

Correct, there's no engine on this tool - it's a fully passive attachment that runs entirely off the carrier's hydraulics. What reads like an engine quirk is really the gerotor drive motor and how well it's matched to the host machine. Gerotor motors are simple and inexpensive to service compared to piston motors, but they're also less tolerant of contaminated oil or the carrier running at the wrong flow setting - reduced torque and accelerated internal wear are the typical symptoms reported. There's no documented pattern of motor failure independent of flow/pressure mismatch or hydraulic contamination.

Are there electrical or sensor problems to worry about with this trencher?

Very little to none. As a fully passive, hydraulically driven work tool, it carries no ECM, wiring harness, or sensors of its own - it runs entirely off the carrier's auxiliary hydraulic circuit and in-cab controls. Reports of electrical faults tied to the trencher itself are essentially nonexistent; any symptom that looks electrical traces back to the carrier's own auxiliary-hydraulics wiring or attachment-detection circuitry, not the tool.

Is the T15 basically the same as the T15B, or should I expect different specs?

The T15 is the earlier tool in this Cat trencher line, predecessor to the later T15B update. Parts and service documentation treat them as related but separate serial families rather than a straight carryover, so boom length, cut width, and maximum system pressure are best treated as varies by series rather than assumed identical between the two. The T15B is documented with roughly a 1524 mm (60 in) boom, about 203 mm (8 in) cut width, and a 290 bar (4205 psi) maximum operating pressure - useful as a family reference point, but not confirmed numbers for the bare T15 until you check the specific serial plate against dealer documentation.

What should I check before buying a used T15?

Work the inspection from boom tip back to the mount plate. Rock the end idler side to side to check for bearing play, look at both sides of the boom wear strips for thin spots, and pull on the chain to check sag while looking for stretched pins, cracked links, or teeth worn past the carbide insert. Check the drive sprocket teeth for thinning caused by running against a worn chain. Inspect hydraulic hoses and quick-couplers for cracking, leaks, or swelling, and confirm the mounting plate matches your carrier's coupler type. Because documentation for the bare T15 is thinner than for the later T15B, confirm the serial prefix and verify flow/pressure specs for that specific serial range with your dealer rather than assuming T15B numbers apply directly.

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

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