CAT 320C 320D Swing Gearbox 148-4644 — OEM-Spec Swing Motor Drive Reducer
Part No. 148-4644 · Stock Code: 9201952 · Equipment: CAT 320C / 320D Excavator
CAT 320C 320D Swing Gearbox 148-4644 — OEM-Spec Swing Motor Drive Reducer
100% Load-Tested
3-Month Warranty
No MOQ
Video Inspection Provided
What Is the CAT 320C 320D Swing Gearbox — and What Does It Do?
The CAT 320C 320D swing gearbox (part number 148-4644) is a multi-stage planetary gear reducer that sits between the hydraulic swing motor and the machine's ring gear. It converts high-speed, low-torque motor output into the slow, high-torque rotation that drives the full 360° movement of the excavator's upper structure — cab, boom, arm, and bucket — through every dig-and-swing cycle.
A failed CAT 320 swing gearbox grounds the machine entirely. No upper-body rotation means no productive excavation, loading, or demolition work. This replacement is built to Caterpillar OEM dimensional tolerances: bolt patterns, shaft diameters, and port locations all match the factory unit. Average field swap time is 4–6 hours with standard workshop tooling — no shimming, no adaptor plates, no surprises.
Every unit ships with a signed machinery test report and a video outgoing-inspection recording, so you can verify condition before the crate is opened.
Product Specifications
Dimensional drawings available before order on request. Verify your machine serial number prefix for serial-specific variants.
| Parameter | Details |
|---|---|
| Part Number | 148-4644 |
| Stock Code | 9201952 |
| Compatible Equipment | Caterpillar 320C / 320D Excavator (primary) — 130+ models, see compatibility table |
| Product Category | Construction Machinery Parts — Swing Gearbox / Swing Motor Drive Reducer |
| Item Condition | New |
| Application Type | Direct OEM replacement — no shimming, adaptor plates, or rework required |
| Warranty | 3 months from date of arrival (manufacturing defects under rated conditions) |
| Minimum Order Quantity | No minimum — order as few as 1 unit |
| Quality Documentation | Machinery test report + video outgoing inspection — both provided with every order |
| Inner Packaging | Wrapped in plastic film; clear individual label per item |
| Outer Packaging | Carton or plywood case (packing size depends on type) |
| Shipping Methods | Sea freight, air freight, express carrier (DHL / FedEx / UPS) |
| Port | Jiangmen, China (negotiable) |
| Trade Terms | EXW, FOB, CFR, CIF |
| Payment Terms | T/T, Western Union, Escrow |
| Lead Time | In stock: 4–7 days processing & packing | Bulk: 10–35 days (qty-dependent) |
| Applicable Industries | Construction, Energy & Mining, Manufacturing, Agriculture, Machinery Repair, Building Materials |
Why Buyers Choose This CAT 320 Swing Gearbox
Numbers only — no filler claims.
Every unit runs a no-load run-in then full rated-torque bench test. Signed test report ships with the unit. A unit that doesn't pass doesn't ship — no exceptions.
Manufactured to CAT 320C/320D dimensional tolerances. Bolt pattern, shaft diameter, and hydraulic port positions all match the factory swing gearbox. Average install: 4–6 hours.
No minimum order quantity. Single-unit machine-down orders ship on the same lead time as bulk. Volume pricing available — contact us with quantity for a tiered quote.
In-stock units packed and ready within 4–7 business days. Bulk production: 10–35 days depending on volume. Air freight available for urgent breakdowns.
Video inspection of each shipment is recorded and available. You can verify the physical condition of the 148-4644 swing gearbox before it leaves our facility.
3-month warranty starts when goods arrive with you — not our ship date. Defective units replaced. Report with photos and data; we handle the rest.
Applicable Excavator Models — 130+ Machines Covered
Part 148-4644 covers excavators across 6 weight classes — from mini machines below 10t to heavy units above 50t. Verify your machine serial prefix before ordering for serial-specific variants.
20 10–20t
35 20–30t
21 30–40t
7 40–50t
2 50t+
| Below 10t | 10t Up | 20t Up | 30t Up | 40t Up | 50t Up |
|---|---|---|---|---|---|
| E307B | E315 | DH220-5 | E330 | DH420-7 | DH500-7 |
| E70B-7 | EX120-5 | DH225-7 | E330C | CE420-6 | EC700 |
| EX60-2 | ZX120 | DH225-9 | E330D | EC460 | — |
| EX60-5 | E200B | DH370-7 | E336D | EC460B | — |
| ZX60 | SK135 | E320C ✦ | PC300-7 | PC400-6 | — |
| ZX70 | PC120-6 | E320D ✦ | PC360-7 | PC400-7 | — |
| ZX75 | PC160-7 | E318C | PC300-8 | PC450-7 | — |
| ZX80 | TB135 | E319C | PC300-8MO | — | — |
| ZX85 | R130 | EC210 | SK330-8 | — | — |
| PC40-7 | DH150-7 | EC240 | SK350-8 | — | — |
| PC56 | DH258 | EC240B | EC350 | — | — |
| PC60-6 | HD400-5-7 | EC290 | EC360B | — | — |
| PC60-7 | SH120 | EC290BLC | EC380 | — | — |
| SK55 | SH280 | HD700-7 | R300 | — | — |
| SK60-5 | CX130 | JS200 | R375-7 | — | — |
| SK60-6 | XE150 | PC200-6 | DH300-7 | — | — |
| SK60-8 | FR150 | PC200-7 | DX380 | — | — |
| SK70 | FR170 | PC200-8 | HD1250 | — | — |
| SK75UR | SY135 | PC220-7 | SH350-5 | — | — |
| EC55 | LG915 | R210-7 | CASE360 | — | — |
| SOLAR 55-V | — | CX210 | LG936 | — | — |
| DH55 / DH60 / DH80 | — | SH200 / SK200-5-6 | — | — | — |
| R60-5 / FR39 | — | SK200-8 / S265FA | — | — | — |
| LG6085 / LG907 | — | LG200 / LG210 / LG225 | — | — | — |
| SWE35 / SWE40 / SWE45 | — | LG230 / LG200-3 / LG220-3 | — | — | — |
| SWE50 / SWE70 / YC35 / YC60-7 / YC65-2 / YC85 | — | LG925 / XE240 / LG240 | — | — | — |
✦ Primary fit. Not sure about your variant? Send your machine serial number prefix and we'll confirm within 4 business hours — no charge.
Application Scenarios
The CAT 320C 320D swing gearbox is in service across four main operating environments, each placing distinct demands on the swing drive.
Continuous 360° swing during trenching, foundation work, and demolition. High-cycle operations accelerate gear wear — prompt swing gearbox replacement keeps daily productivity on target.
Open-pit loading and energy infrastructure in abrasive, dusty environments. A leaking seal on the 320 swing gearbox lets contaminated oil destroy gear surfaces within 200 operating hours.
Irrigation channel work and farm land preparation. Seasonal-intensive then idle for months — extended storage is where inadequate corrosion protection on the gearbox housing shows up as premature failure.
Workshops servicing CAT and compatible fleets. No MOQ means stocking a single unit for unplanned breakdowns is cost-effective. 4–7 day in-stock lead time supports same-week turnaround on repairs.
After-Sales Support & Warranty Terms
3-month warranty from the date goods arrive with you — not from our ship date. Defective units are replaced directly. Inspect against the packing list on arrival; report issues with photos and item data promptly.
Bearings, seals, and other specified consumable components are excluded from warranty — declared before every order. For all other components we manufacture, we stand behind the product.
- Incorrect part ordered by buyer
- Damage from natural disasters or accidents
- Incorrect installation or misuse
- Operation beyond rated load or rated hours
- Human-caused physical damage
- Corrosion from improper storage or environment
- Warranty period expired
- Submit part number, model, quantity, and delivery terms.
- We quote within 24 hours.
- Confirm PO and pay deposit.
- We prepare and pack your order.
- Pay balance per Proforma Invoice once goods are ready.
- We ship with packing list, commercial invoice, B/L, and any additional requested documents.
- Track shipment through to arrival.
- Share feedback — we act on it.
Frequently Asked Questions
Customer Reviews
"We had a 320D down on an active mining site. Ordered this, chose air freight, gearbox arrived in 6 days, went straight on. No modifications, no surprises — just the machine swinging again the next morning. The signed test report meant our site compliance team was satisfied without extra paperwork."
"I've been burned by 'OEM-spec' parts that fit like I fit into my high school jeans — technically possible, emotionally painful. This 148-4644 bolted onto our 320C like it was born there. Came with an actual test report, not a typed note from someone named Steve. Three months running clean. Ordered two more."
Frequently Ordered Together
Internal gearbox failure contaminates two adjacent components. Replace them in the same service window and eliminate the most common secondary failures within 500 operating hours.
Metal debris from gearbox failure reaches the swing motor case drain within 1–2 hours of continued operation. After confirming contamination, replacement is the safe call. OEM-spec rebuild and new units available.
Complete set: output shaft seal, input seal, internal O-rings, and swing post output bearing. Replacing the post bearing when fitting a new CAT 320 swing gearbox eliminates the most common secondary failure point. Can ship with the main unit.
Order Your CAT 320C 320D Swing Gearbox — Get a Quote in 24 Hours
A grounded CAT 320C 320D swing gearbox replacement (part 148-4644) is in stock now. No minimum order. Send your machine model, serial number, shipping port, and quantity — confirmed price and lead time within 24 business hours. 3-month warranty from arrival. 100% load-tested. Test report and video inspection included.
✓ No MOQ
✓ 3-Month Warranty from Arrival
✓ Test Report + Video Inspection
✓ Sea / Air / DHL · EXW FOB CIF
📧 [email protected] | 24h response | Jiangmen Port | 130+ compatible models
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