Caterpillarwork toolgrapple-dem/sort

Caterpillar G320

Maintenance schedule, common problems & OEM parts breakdown

The Cat G320 is a passive hydraulic sorting and demolition grapple, a stick-mounted work tool rather than a self-propelled machine. It pairs with the C-linkage Cat 325B L or the D-linkage Cat 330B L excavator, drawing all its power from the host carrier's boom, stick, and auxiliary hydraulic circuit. Operating weight is about 2060 kg (4542 lb) including its mounting bracket, and its ribbed jaw carries a heaped capacity of roughly 900 L (1.17 cu yd). Sitting between the smaller G315 and the larger G330 in Caterpillar's sorting-and-demolition grapple lineup, the G320 is built for non-concrete demolition, debris sorting, scrap handling, and site cleanup, where its fast jaw cycle and full 360-degree rotation let an operator feather material onto a conveyor or sort a mixed debris pile load by load.

The G320 has no engine, transmission, or fuel system of its own, so nearly everything that wears is mechanical or hydraulic: pivot pins, bushings, cylinder seals, hoses, wear plates, and the rotator bearing. That keeps well-maintained units in service long after the excavators they were originally matched to have been retired, and buyers in the used and rebuild market look for this class of tool mainly for pin-and-bushing kits, cylinder seal kits, wear plates, and rotator components rather than powertrain parts. Caterpillar later introduced the G320B as the direct successor in this line, with its own carrier fitment and capacity figures. The two share a naming family but are distinct tools, and specs, cycle times, and parts should not be assumed interchangeable between them.

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 G320 specifications

Hydraulic requirements

Power source	No onboard tank or pump. Jaw cylinder and rotator run entirely off the host excavator's auxiliary hydraulic circuit through quick-disconnect couplers.
Jaw (clamp) circuit flow, max	100 L/min (26.4 gpm)
Jaw (clamp) circuit pressure, max	35 000 kPa / 35 MPa (5075 psi)
Rotation circuit flow, max	40 L/min (10.6 gpm)
Rotation circuit pressure, max	14 000 kPa / 14 MPa (2030 psi)
Rotator	Hydraulic 360-degree continuous-rotation drive on a slewing ring, fed and controlled from the host machine's auxiliary circuit. No independent torque rating published.

Weights

Operating weight (incl. mounting bracket)	2060 kg (4542 lb)
Configuration note	One weight figure published for the G320; no separate jaw/housing weight variants documented.

Dimensions

Overall length, grapple closed	1505 mm (59 in)
Overall length, grapple open	2265 mm (89 in)
Overall width	1394 mm (55 in)
Overall height, grapple closed	1850 mm (72.8 in)
Overall height, grapple open	1690 mm (66.5 in)
Mounting/linkage interface	Linkage class C when carried on a Cat 325B L stick (stick range 2.7-3.2 m / 8 ft 10 in - 10 ft 6 in); linkage class D when carried on a Cat 330B L stick (stick range 3.3-3.9 m / 10 ft 10 in - 12 ft 10 in). Mounts via a dedicated adapter-bracket plate and 360-degree slewing ring at the pivot.

Capacity / Performance

Heaped capacity	900 L (1.17 cu yd)
Rated closing (clamp) force	60 kN (approx. 6.7 metric ton-force)
Open/close cycle time	Approx. 1.7 seconds per cycle at rated flow
Rotation speed	Continuous 360-degree hydraulic rotation; a full 360-degree turn takes about 4 seconds at recommended oil flow
Host machine class	Matched to Cat 325B L and 330B L class excavators (325/330-class carriers)
Cutting edge / wear material	Cutting edges in Hardox-grade steel, protected by bolt-on replaceable wear plates in Cat's proprietary DH2 steel (hardness near 50 RC); plates can be indexed 180 degrees to extend service life

Service

Lubrication	Grease the jaw cylinder pin ends, grapple pivot pins, and the rotator slewing-ring bearing on the standard work-tool lube schedule. No engine, fuel, coolant, or onboard hydraulic-tank service applies to this attachment.
Fluid supply	Hydraulic fluid is supplied and serviced entirely through the host excavator's own hydraulic system; the grapple carries no reservoir of its own.
Wear items	Bolt-on wear plates and side plates are field-replaceable/reversible; check and rotate or replace per inspection rather than on a fixed interval.

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

G320 fluids & capacities

System	Capacity	Recommended fluid
Grease points - jaw/tine pivot pins, housing bushings, and hydraulic rotator bearing/slewing ring	No independent fill capacity applies. The G320 is a passive hydraulic demolition and sorting grapple with grease nipples at each housing pivot pin and bushing plus the integral 360-degree hydraulic rotator/slewing ring. It carries no engine, fuel tank, cooling system, or hydraulic reservoir of its own. Both the jaw-cylinder clamp circuit and the rotator circuit run entirely off the host excavator's auxiliary hydraulic supply through quick-disconnect couplers, so hydraulic oil type and tank capacity are covered under the host machine's own fluid chart, not this work tool's.	Cat multipurpose EP grease with moly additive, NLGI 2, applied at every grease fitting on the pivot pins, bushings, and rotator bearing. Cat's standard-duty spec for this class of pin joint and slew bearing is Cat Advanced 3Moly Grease (lithium-complex base, 3% molybdenum disulfide), rated for roughly -20 to 40 degC (-4 to 104 degF) ambient. For sustained heavy demolition/sorting duty, high shock load, or hot-climate operation, Cat Extreme Application Grease (calcium-sulfonate EP formula, roughly -15 to 140 degC / 5 to 284 degF) is the severe-duty alternative some dealers recommend for grapple pin joints. Grease all points daily under continuous production use, or at minimum every 10 service hours; confirm the exact interval and grease callout for your serial range in the work tool's own OMM or with your dealer. No separate hydraulic-fluid type or cleanliness spec is published for the G320 circuit itself; use the grade and cleanliness level called out in the host excavator's OMM for its auxiliary hydraulic system.

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

Caterpillar G320 maintenance schedule

Service interval	Tasks
Every 10 h	Wipe down the jaw and rotator and check hose fittings and quick-disconnect couplers for visible hydraulic leaks. Check hose routing and hose guards for chafing, kinks, or contact with the jaw frame during full-open and full-close travel. Inspect wear plates and cutting edges for cracks, gouges, or loose mounting bolts. Confirm quick-disconnect couplers seat fully and lock before returning the tool to work. Grease the jaw pivot pins if the tool is running high-cycle demolition or sorting work that day.
Every 50 h	Grease every jaw pivot pin and bushing fitting, cycling the jaw fully open and closed to work grease into each bushing. Grease the rotator bearing and rotation-drive fitting. Inspect the jaw cylinder rod and barrel for scoring, pitting, or seal weep. Check mounting bracket bolts and adapter plate fasteners for correct torque. Inspect hose clamps, guards, and quick-disconnect couplers for wear or damage.
Every 250 h	Check jaw side-play and vertical play at each pivot joint to gauge pin and bushing wear. Inspect the rotator drive and slewing ring for excess backlash or abnormal noise under load. Inspect the cylinder seals and rod wiper for leakage and replace worn seals before they fail in service. Inspect wear plates, cutting edges, and reinforcing bars for material loss; flip reversible wear plates once the working face wears down. Inspect welds on the jaw frame, housing, and mounting bracket for cracking, especially near pin bosses. Sample hydraulic oil from the host carrier's auxiliary circuit for contamination if the tool has been in heavy demolition duty.
Every 500 h	Measure pin and bushing wear against service limits and replace any pin-and-bushing set that exceeds allowable clearance. Inspect the rotator/slewing ring bearing for pitting and check its mounting bolts for correct torque. Replace the jaw cylinder seals and quick-disconnect couplers as matched sets rather than individually. Inspect the full structural weldment on the jaw halves, housing, and mounting bracket for cracking. Touch up or repaint worn steel surfaces to protect against corrosion from scrap and demolition debris.

Servicing the G320 beyond the schedule

Predictive Maintenance & Fluid Analysis

The G320 has no fluid reservoir of its own; its jaw cylinder and rotator draw entirely off the host excavator's auxiliary hydraulic circuit through quick-disconnect couplers. Track oil cleanliness at the carrier's auxiliary circuit rather than the tool itself, since abrasive demolition debris accelerates particulate contamination faster than typical bucket work. Log jaw side-play and rotator backlash at each service interval to catch pin and bushing wear before it becomes play severe enough to affect clamping alignment or rotation smoothness.

Corrective & Common Repairs

Most G320 repairs center on the jaw cylinder, hoses, and wear surfaces. Cylinder seal and rod wiper replacement is the most common internal repair once the tool starts weeping oil at the barrel or rod. Damaged hoses and worn quick-disconnect couplers should be replaced as matched pairs to keep flow balanced between the jaw and rotator circuits. Wear plates and cutting edges bolt on for a reason: flip or replace them once the edge rounds off or the plate thins, before the underlying jaw structure takes the wear instead.

Overhaul & Rebuild Points

A full G320 rebuild centers on the pin-and-bushing joints, the rotator, and the housing weldment. Pins and bushings at the jaw pivots and cylinder clevises take the most cyclic load in demolition work and are usually first to need replacement. The 360-degree rotator and its slewing ring wear from constant reversing under load; inspect for bearing pitting and backlash at overhaul. Cracked welds on the jaw halves, housing, or mounting bracket call for gouging out and rewelding to full section thickness, not a cosmetic pass.

Seasonal & Environment Servicing

Demolition and scrap sites expose the G320 to concrete dust, wood splinters, and metal fines that pack into grease points and accelerate pin wear, so grease more often than the base interval in dusty or gritty conditions. In cold climates switch to a lower-viscosity grease so pivot pins and the rotator bearing still get full lubrication at startup. Because it works in corrosive scrap and demolition debris, touch up worn paint on the jaw and housing and keep quick-disconnect couplers capped when idle to keep grit out of the circuit.

G320 fault codes & troubleshooting

Code	Meaning	Likely cause	What to do
CID 1180 (Auxiliary Hydraulic Solenoid #1) — host excavator code	Host excavator ECM diagnostic for the first auxiliary hydraulic control solenoid, the circuit supplying the work tool's primary function such as jaw open/close on a grapple.	Open or short circuit in the aux solenoid wiring or connector, a failed solenoid coil, or a stuck auxiliary valve spool on the host machine.	Read active and logged codes on the host excavator with the OEM diagnostic tool, then inspect the auxiliary solenoid wiring and connector at the machine before checking the attachment's own hoses and cylinder.
CID 1181 (Auxiliary Hydraulic Solenoid #2) — host excavator code	Host excavator ECM diagnostic for the second auxiliary hydraulic control solenoid, the circuit typically used for a secondary function such as rotation on a rotating grapple.	Open or short circuit in the second aux solenoid wiring or connector, a failed coil, or a valve spool fault on the host machine's auxiliary circuit.	Read active and logged codes on the host excavator with the OEM diagnostic tool, then inspect the second auxiliary solenoid wiring and connector before checking the rotator drive itself.

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

G320 attachments & work tools

Host carrier compatibility

Designed to mount on the Cat 325B L excavator (stick length 2.7-3.2 m / 8'10"-10'6", C-linkage) and the Cat 330B L excavator (stick length 3.3-3.9 m / 10'10"-12'10", D-linkage). It belongs to a demolition and sorting grapple lineup built for excavators spanning roughly the 320B through 345B size class.

Mounting/coupler interface

Mounts through a top plate for an adapter bracket matched to the host excavator's specific stick linkage, giving a positive mechanical pin-on connection rather than a quick-coupler interface. The bracket sits above the grapple's own integral rotation ring, and quoted grapple weight figures include this mounting bracket.

Housing/jaw configuration options

Jaw cutting edges are protected by bolt-on wear plates, roughly 25 mm (1 in) thick, in wear-resistant steel that can be reversed to extend service life, with welded horizontal bars reinforcing the vertical jaw ribs. Bolt-on side plates are offered as an option to close the rib cage for handling smaller-sized debris and material.

Rotator/hydraulic kit

360-degree hydraulic rotation is built into the grapple through an integral slewing ring rather than a separate add-on kit, completing a full turn in about 4 seconds at rated flow. The rotation circuit runs on its own hydraulic supply, up to 40 l/min (10.6 gpm) at 14,000 kPa (2,030 psi), separate from the higher-flow jaw-cylinder circuit rated up to 100 l/min (26.4 gpm) at 35,000 kPa (5,075 psi).

All G320 assemblies by section

Every catalogued assembly group for the Caterpillar G320. Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.

Frame And Body

193-5362 Housing Gp-Grapple

09***48	Nipple, Grease	8
12***81	Bolt-Socket Head; (M10x1.5x55-mm)	2
14***78	Lockwasher	4
15***18	Lockwasher	13

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193-5353 Housing Gp-Grapple

09***48	Nipple, Grease	8
12***81	Bolt-Socket Head; (M10x1.5x55-mm)	2
14***78	Lockwasher	4
15***38	Tee As	1

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174-7842 Housing Gp-Grapple

09***48	Nipple, Grease	8
12***81	Bolt-Socket Head; (M10x1.5x55-mm)	2
14***78	Lockwasher	4
15***38	Tee As	1

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174-1657 Housing Gp-Grapple

09***48	Nipple, Grease	8
12***81	Bolt-Socket Head; (M10x1.5x55-mm)	2
14***78	Lockwasher	4
15***38	Tee As	1

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174-9093 Housing Gp-Grapple

09***48	Nipple, Grease	8
12***81	Bolt-Socket Head; (M10x1.5x55-mm)	2
14***78	Lockwasher	4
15***38	Tee As	1

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193-5358 Housing Gp-Grapple

09***48	Nipple, Grease	8
12***81	Bolt-Socket Head; (M10x1.5x55-mm)	2
14***78	Lockwasher	4
15***38	Tee As	1

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187-4372 Sideboard Gp-Grapple

15***22	Lockwasher	12
17***40	Screw-Flat Head; (M24x3x90mm)	12
18***70	Plate As-Rh	2
18***72	Sideboard Group-Grapple	1

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187-4371 Sideboard Gp-Grapple

15***22	Lockwasher	12
17***40	Screw-Flat Head; (M24x3x90mm)	12
18***69	Plate As-Rh	2
18***71	Sideboard Group-Grapple	1

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Hydraulic System

174-1679 Cylinder Gp-Hydraulic

09***48	Nipple, Grease	2
12***09	Bearing	2
17***79	Cylinder Group-Hydraulic	1
17***68	Cylinder As	1

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177-5046 Lines Gp-Connecting

17***20	Hose As	2
17***46	Lines Group-Connecting	1
5K***90	Seal-To Hydraulic Cooler Inlet Port	2
6V***48	Reducer Assembly	2

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177-5024 Lines Gp-Connecting

17***20	Hose As	2
17***24	Lines Group-Connecting	1
1P***04	Seal - Rectangular (45mm Dia)	1
1P***67	Flange-Half (43.31 mm Id)	2

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177-5019 Lines Gp-Connecting

17***19	Lines Group-Connecting	1
17***20	Hose As	2
7K***81	Strap-Pressure & Return Hoses To	4

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177-5021 Lines Gp-Connecting

12***40	Fitting As-Hydraulic; (Quick Disconnect, Male)	2
17***21	Lines Group-Connecting	1
17***22	Hose As	2
6V***98	Seal-O-Ring -Line From Gear Pump Output	4

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177-5023 Lines Gp-Connecting

17***20	Hose As	2
17***23	Lines Group-Connecting	1
1P***04	Seal - Rectangular (45mm Dia)	2
1P***67	Flange-Half (43.31 mm Id)	4

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177-5129 Lines Gp-Connecting

12***40	Fitting As-Hydraulic; (Quick Disconnect, Male)	2
17***29	Lines Group-Connecting	1
17***45	Hose As	2
6V***98	Seal-O-Ring -Line From Gear Pump Output	4

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229-4905 Lines Gp-Connecting

11***49	Fitting; (Quick Disconnect, Male)	2
1P***04	Seal - Rectangular (45mm Dia)	2
1P***67	Flange-Half (43.31 mm Id)	4
22***05	Lines Group-Connecting	1

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228-9797 Lines Gp-Connecting

11***49	Fitting; (Quick Disconnect, Male)	2
1P***02	Seal-Rectangular 28.83mm(1.136in) Id	2
22***97	Lines Group-Connecting	1
22***19	Hose As	2

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170-2174 Manifold Gp-Control

14***20	Bolt-Socket Head; (M6x1x75-mm)	4
17***74	Manifold Group-Control	1
7Y***19	Seal-O-Ring (Id=12.37mm)	2

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170-2172 Motor & Manifold Gp-Rotator

17***72	Motor & Manifold Group-Rotator	1
17***73	Motor Group-Gerotor	1
17***74	Manifold Group-Control	1
17***76	Ring-Mounting	1

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170-2173 Motor Gp-Gerotor

17***73	Motor Group-Gerotor	1
17***21	Kit-Housing	1
17***22	Shaft-Output	1
17***25	Key-Square	1

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171-7526 Rotator Gp-Hydraulic

03***43	Seal-O-Ring	1
09***48	Nipple, Grease	1
14***70	Elbow, 90°,-8 Orb Swiv. /-8 Orfs	2
15***94	Adapter As	6

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169-6060 Rotator Gp-Hydraulic

03***43	Seal-O-Ring	1
08***09	Spacer; (16.6x32x8.5-mm Thk)	34
12***28	Adaptor - Includes:-	2
15***94	Adapter As	6

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170-3045 Swivel Gp

16***43	Seal	1
17***45	Swivel Group	1
17***41	Stator	1
17***42	Rotor	1

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Service Equipment And Supplies

174-7864 Plate & Film Gp

14***36	Film-Warning; (Flying Debris)	2
14***69	Film-Warning; (Alert)	2
14***70	Film-Warning; (Read Omm)	2
15***35	Film-Warning; (Crush Hazard, Stay Back)	2

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174-9092 Plate & Film Gp

14***36	Film-Warning; (Flying Debris)	2
14***69	Film-Warning; (Alert)	2
14***70	Film-Warning; (Read Omm)	2
15***35	Film-Warning; (Crush Hazard, Stay Back)	2

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204-4257 Plate & Film Gp

14***36	Film-Warning; (Flying Debris)	2
14***69	Film-Warning; (Alert)	2
14***70	Film-Warning; (Read Omm)	2
15***35	Film-Warning; (Crush Hazard, Stay Back)	2

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204-4263 Plate & Film Gp

14***36	Film-Warning; (Flying Debris)	2
14***69	Film-Warning; (Alert)	2
14***70	Film-Warning; (Read Omm)	2
15***35	Film-Warning; (Crush Hazard, Stay Back)	2

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174-1656 Plate & Film Gp

14***36	Film-Warning; (Flying Debris)	2
14***69	Film-Warning; (Alert)	2
14***70	Film-Warning; (Read Omm)	2
15***35	Film-Warning; (Crush Hazard, Stay Back)	2

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204-4260 Plate & Film Gp

14***36	Film-Warning; (Flying Debris)	2
14***69	Film-Warning; (Alert)	2
14***70	Film-Warning; (Read Omm)	2
15***35	Film-Warning; (Crush Hazard, Stay Back)	2

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Work Tool Arrangement

174-9091 Grapple Ar-Hydraulic

14***08	Fitting	2
14***86	Fitting As	2
15***44	Seal	1
17***77	Fitting As; (Quick Disconnect, Male)	4

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193-5361 Grapple Ar-Hydraulic

14***08	Fitting	2
14***86	Fitting As	2
15***44	Seal	1
17***77	Fitting As; (Quick Disconnect, Male)	4

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174-1655 Grapple Ar-Hydraulic

14***08	Fitting	2
14***86	Fitting As	2
15***44	Seal	1
17***77	Fitting As; (Quick Disconnect, Male)	4

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174-7841 Grapple Ar-Hydraulic

14***08	Fitting	2
14***86	Fitting As	2
15***44	Seal	1
17***77	Fitting As; (Quick Disconnect, Male)	4

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193-5352 Grapple Ar-Hydraulic

14***08	Fitting	2
14***86	Fitting As	2
15***44	Seal	1
17***77	Fitting As; (Quick Disconnect, Male)	4

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193-5357 Grapple Ar-Hydraulic

14***74	Fitting As	2
14***86	Fitting As	2
15***44	Seal	1
17***77	Fitting As; (Quick Disconnect, Male)	4

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Work Tools

179-1646 Bracket Gp-Mounting

15***18	Lockwasher	8
16***97	Plate-Cover	1
17***45	Bracket As	1
17***46	Bracket Group-Mounting	1

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169-4968 Bracket Gp-Mounting

16***68	Bracket Group-Mounting	1
16***82	Bolt-Socket Head; (M24x3x70-mm)	14
23***05	Bracket As	1
7Y***10	Washer-Special; (17x65x6-mm Thk)	2

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169-5312 Bracket Gp-Mounting

16***12	Bracket Group-Mounting	1
16***82	Bolt-Socket Head; (M24x3x70-mm)	14
17***54	Bracket Group-Mounting	1
8T***67	Washer-Hard; (26x44x4-mm Thk)	14

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254-4039 Bracket Gp-Mounting

09***49	Washer; (22x60x6-mm Thk)	1
13***55	Setscrew; (M4x0.7x8-mm)	2
16***82	Bolt-Socket Head; (M24x3x70-mm)	14
20***71	Washer; (26x90x8-mm Thk)	1

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179-1654 Bracket Gp-Mounting

15***18	Lockwasher	8
16***15	Bracket As	1
16***97	Plate-Cover	1
17***54	Bracket Group-Mounting	1

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169-4981 Bracket Gp-Mounting

16***81	Bracket Group-Mounting	1
16***99	Bracket As	1
16***82	Bolt-Socket Head; (M24x3x70-mm)	14
7X***53	Bolt-Plt; (M16 X 2.0 X 40)	1

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193-4497 Bracket Gp-Mounting

16***82	Bolt-Socket Head; (M24x3x70-mm)	14
19***97	Bracket Group-Mounting	1
20***66	Bracket Group-Mounting	1
8T***67	Washer-Hard; (26x44x4-mm Thk)	14

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190-5435 Bracket Gp-Mounting

16***82	Bolt-Socket Head; (M24x3x70-mm)	14
19***35	Bracket Group-Mounting	1
19***36	Bracket As	1
8T***67	Washer-Hard; (26x44x4-mm Thk)	14

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169-5307 Bracket Gp-Mounting

16***07	Bracket Group-Mounting	1
16***82	Bolt-Socket Head; (M24x3x70-mm)	14
17***47	Bracket Group-Mounting	1
8T***67	Washer-Hard; (26x44x4-mm Thk)	14

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175-0338 Bracket Gp-Mounting

16***82	Bolt-Socket Head; (M24x3x70-mm)	14
17***38	Bracket Group-Mounting	1
17***46	Bracket Group-Mounting	1
8T***67	Washer-Hard; (26x44x4-mm Thk)	14

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179-1647 Bracket Gp-Mounting

15***18	Lockwasher	8
16***19	Bracket As	1
16***97	Plate-Cover	1
17***47	Bracket Group-Mounting	1

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169-4971 Bracket Gp-Mounting

16***71	Bracket Group-Mounting	1
16***91	Bracket As	1
16***82	Bolt-Socket Head; (M24x3x70-mm)	14
7X***53	Bolt-Plt; (M16 X 2.0 X 40)	2

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169-5311 Bracket Gp-Mounting

16***11	Bracket Group-Mounting	1
16***16	Bracket As	1
16***82	Bolt-Socket Head; (M24x3x70-mm)	14
8T***67	Washer-Hard; (26x44x4-mm Thk)	14

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169-4978 Bracket Gp-Mounting

16***78	Bracket Group-Mounting	1
16***97	Bracket As	1
16***82	Bolt-Socket Head; (M24x3x70-mm)	14
7X***53	Bolt-Plt; (M16 X 2.0 X 40)	1

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169-4969 Bracket Gp-Mounting

16***69	Bracket Group-Mounting	1
16***89	Bracket As	1
16***82	Bolt-Socket Head; (M24x3x70-mm)	14
7X***53	Bolt-Plt; (M16 X 2.0 X 40)	2

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169-4970 Bracket Gp-Mounting

16***70	Bracket Group-Mounting	1
16***90	Bracket As	1
16***82	Bolt-Socket Head; (M24x3x70-mm)	14
7Y***10	Washer-Special; (17x65x6-mm Thk)	2

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169-5308 Bracket Gp-Mounting

16***08	Bracket Group-Mounting	1
16***82	Bolt-Socket Head; (M24x3x70-mm)	14
17***45	Bracket Group-Mounting	1
8T***67	Washer-Hard; (26x44x4-mm Thk)	14

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169-4976 Bracket Gp-Mounting

16***76	Bracket Group-Mounting	1
16***96	Bracket As	1
16***82	Bolt-Socket Head; (M24x3x70-mm)	14
7X***53	Bolt-Plt; (M16 X 2.0 X 40)	1

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169-4974 Bracket Gp-Mounting

16***74	Bracket Group-Mounting	1
16***93	Bracket As	1
16***82	Bolt-Socket Head; (M24x3x70-mm)	14
7X***53	Bolt-Plt; (M16 X 2.0 X 40)	2

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169-4975 Bracket Gp-Mounting

13***55	Setscrew; (M4x0.7x8-mm)	2
16***75	Bracket Group-Mounting	1
16***94	Bracket As	1
16***82	Bolt-Socket Head; (M24x3x70-mm)	14

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209-1776 Bracket Gp-Mounting

13***55	Setscrew; (M4x0.7x8-mm)	2
16***82	Bolt-Socket Head; (M24x3x70-mm)	14
20***59	Plate-Serial Number	1
20***76	Bracket Group-Mounting	1

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175-0342 Bracket Gp-Mounting

16***82	Bolt-Socket Head; (M24x3x70-mm)	14
17***42	Bracket Group-Mounting	1
17***49	Bracket As	1
7X***52	Bolt-Plt; (M16 X 2.0 X 30)	2

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175-0341 Bracket Gp-Mounting

16***82	Bolt-Socket Head; (M24x3x70-mm)	14
17***41	Bracket Group-Mounting	1
17***48	Bracket As	1
7X***52	Bolt-Plt; (M16 X 2.0 X 30)	2

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169-4980 Bracket Gp-Mounting

16***80	Bracket Group-Mounting	1
16***98	Bracket As	1
16***82	Bolt-Socket Head; (M24x3x70-mm)	14
7X***52	Bolt-Plt; (M16 X 2.0 X 30)	2

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201-9466 Bracket Gp-Mounting

15***18	Lockwasher	8
16***97	Plate-Cover	1
20***66	Bracket Group-Mounting	1
20***31	Bracket As	1

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179-1645 Bracket Gp-Mounting

15***18	Lockwasher	8
16***18	Bracket As	1
16***97	Plate-Cover	1
17***45	Bracket Group-Mounting	1

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174-7845 Edge Gp-Cutting

17***45	Edge Group-Cutting	1
18***48	Edge-Cutting	2
2J***05	Nut Rim To Adapter And Adapter To Wheel	24
2J***06	Nut Front Support To Frame; Nut-Front Support To Frame	18

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174-9098 Edge Gp-Cutting

17***98	Edge Group-Cutting	1
18***49	Edge-Cutting	2
2J***06	Nut Front Support To Frame; Nut-Front Support To Frame	18
5J***71	Bolt-Plow; (3/4-10x2.75-In)	18

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174-5567 Edge Gp-Cutting

17***67	Edge Group-Cutting	1
2J***06	Nut Front Support To Frame; Nut-Front Support To Frame	14
5J***73	Bolt 2.06cm(.8125in.)Long	14
7T***91	Sole	2

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179-3479 Grapple Gp

16***60	Rotator Group-Hydraulic	1
17***42	Housing Group-Grapple	1
17***79	Grapple Group	1

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179-3477 Grapple Gp

16***60	Rotator Group-Hydraulic	1
17***57	Housing Group-Grapple	1
17***77	Grapple Group	1

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179-3481 Grapple Gp

17***26	Rotator Group-Hydraulic	1
17***93	Housing Group-Grapple	1
17***81	Grapple Group	1

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193-7174 Grapple Gp

16***60	Rotator Group-Hydraulic	1
19***53	Housing Group-Grapple	1
19***74	Grapple Group	1

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193-7176 Grapple Gp

16***60	Rotator Group-Hydraulic	1
19***62	Housing Group-Grapple	1
19***76	Grapple Group	1

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193-7178 Grapple Gp

17***26	Rotator Group-Hydraulic	1
19***58	Housing Group-Grapple	1
19***78	Grapple Group	1

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G320 serial number reference

The PIN plate for a G320 grapple is a stamped metal tag riveted to the tool's frame or housing, near the mounting bracket or pivot area rather than on a cab. Read the first 3 letters as the prefix and the following digits as the sequential unit number (format PPPNNNNN, e.g. AFA00001), ignoring any leading zeros when matching against a serial break.

Prefix	Identifies	Notes
AFA1-UP	Standard production G320 demolition and sorting grapple	Standard production prefix for the G320 grapple. Mounting-bracket fitment (320/322 excavators with C or S linkage, 322/325/330 with D linkage) matches the G320's typical carrier range.

Frequently asked questions

What excavators does the Cat G320 grapple fit?

The G320 is designed for the Cat 325B L, using the C linkage, and the Cat 330B L, using the D linkage, matched to stick lengths of about 2.7-3.9 m (9-13 ft) depending on the carrier. It is not rated for carriers outside that matching guide.

What is the G320's operating weight and capacity?

Operating weight, including its mounting bracket, is about 2060 kg (4542 lb). Heaped capacity is about 900 L (1.17 cu yd), with a closing force of 60 kN (about 6.7 tons) from its hydraulic jaw cylinder, an oil flow of up to 100 L/min at 35000 kPa (26.4 gpm at 5075 psi).

What replaced the Cat G320?

Caterpillar's later G320B is the direct successor in the sorting-and-demolition grapple line, built around updated carrier fitment. It is a distinct tool from the original G320, so its weight, capacity, and cycle-time figures should not be assumed to apply to this model.

What G320 owners discuss

What wears out first on a grapple like the G320, and how often do wear parts need replacing?

The bolt-on wear plates and tine tips take the brunt of abrasion from concrete, brick, and rebar, and they are the first items operators watch. On grapples in this weight class, cutting edges and tips typically need attention well before the jaw structure itself, with the actual interval driven mostly by material abrasiveness: broken concrete with embedded rebar chews through edges far faster than clean wood or light scrap. Bolt-on wear plates let a crew swap them in the field without welding, which keeps the tool down for hours instead of days. Have your dealer verify current wear-plate and tip condition against your typical material mix.

How do owners manage jaw pivot pin and bushing wear on this type of grapple?

Regular greasing of every pivot point is the standard advice, with shorter intervals when the tool works in mud, demolition dust, or wet sorting conditions. A quick field check is to set the jaw down and try to rock it side to side; a small amount of play is normal, but a noticeable clunk or slop points to a worn pin or bushing. Shop practice is to spec the pin softer than the bushing bore so the cheaper pin wears first and the bushing lasts longer, and when replacement time comes, many shops change pins and bushings together rather than mixing old with new, since a worn pin will quickly ruin a fresh bushing. Have your dealer verify pin-to-bushing clearance before the tool goes back into service.

Where do hydraulic leaks typically show up on a passive grapple attachment like this, since it has no engine of its own?

Everything on this kind of tool runs off the carrier excavator's auxiliary circuit through quick-disconnect couplers at the stick, so those coupler faces and the clamp cylinder seals are the wear points to watch rather than anything resembling a powertrain part. Dirt trapped in the coupler faces is the most common cause of weeping fittings or couplers that are hard to seat, so wiping couplers clean before connecting and bleeding off residual pressure before uncoupling helps avoid fluid loss and premature seal wear. A slow leak at the clamp cylinder rod seal often shows up as the jaw slowly creeping open under load rather than a visible puddle, which is why a daily walkaround should include a look at the rod surface for scoring or seal weep. Have your dealer verify hose and cylinder seal condition if the jaw drifts shut or open on its own or couplers won't seat cleanly.

What should owners watch on the rotator that lets the grapple spin 360 degrees?

The hydraulic rotator is the other component unique to a grapple like this, since it absorbs the twisting load every time a full jaw is spun under load. Rough or jerky rotation, unusual drag, or noise from the slewing ring are the first signs operators look for that the rotator bearing or drive needs attention, and the rotator's grease points are typically kept on the same schedule as the jaw pivot pins. Because the rotator lets the jaw spin freely, it can mask an unbalanced or off-center grab, and repeatedly rotating an overloaded or lopsided load accelerates bearing wear well beyond normal use. Have your dealer verify rotator bearing preload and drag if rotation feels rough or inconsistent.

How do you know if a grapple this size is matched correctly to the excavator it's mounted on?

Getting grapple weight and stick linkage right for the carrier is treated as a basic rule rather than an afterthought. A grapple sized for a larger excavator strains a smaller machine's stick and hydraulics, while an undersized grapple on a bigger carrier wastes capacity and makes fine sorting work harder to control. That is why grapples in this size range are matched against a specific carrier operating-weight band rather than sold as one-size-fits-all, and buyers are told to confirm pin diameter and linkage geometry line up with the coupler before ordering. Have your dealer verify carrier weight class, linkage type, and pin sizing against the grapple before it goes on the machine.

Why does matching hydraulic flow and pressure to the grapple matter, and what happens if it's not matched?

Since the rotator and clamp cylinder both draw off the carrier's auxiliary circuit, matching the excavator's auxiliary flow and pressure to what the tool is built for is treated as being just as important as matching the mechanical size. Pushing more flow through the tool than it is rated for generates excess heat and accelerates seal and bearing wear, while too little flow leaves the jaw sluggish and starves the rotator on heavy grabs. Operators are advised to confirm the carrier's auxiliary flow and pressure settings against the grapple's rated range before regular use, which matters especially on a machine whose auxiliary circuit has previously been set up for a different tool. Have your dealer verify the carrier's auxiliary flow and pressure settings match the grapple's rated range.

What should you check when buying a used G320 grapple?

Start with the housing and mounting plate, looking closely at the weld seams where the mount meets the main frame, since a crack that has been torch-repaired there tends to reopen under load. Next check jaw play: with the tool resting on the ground, rock the jaw to feel for pivot pin and bushing wear, then cycle the clamp under a load to see whether the cylinder holds pressure or the jaw slowly creeps closed on its own, which points to a worn rod seal. Spin the rotator through a full turn with a load in the jaw to feel for drag, rough spots, or noise from the slewing bearing, since a quick static check on an empty jaw can miss this. Bent tine tips and worn wear plates are normal service items on a working tool, but their condition is still a useful read on how hard the grapple has been run. Have your dealer verify housing welds, pin and bushing clearance, cylinder seal condition, and rotator drag before completing the purchase.

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

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