Swing reduction gearboxes, swing motors and travel motors for Kobelco excavators — built for smooth rotation and reliable undercarriage drive.
Part No: YN32W00025F1 / YN32W00022F2 / YN32W00019F1
Precision-machined swing reduction gearbox for smooth rotation and long life.
Compatible: Kobelco SK200-8S, SK210-8S, SK200-10, SK220-10, SK200-8, SK210-8
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Part No: M5X130 / YN15V00077F1 / YN15V00055F1 / YN15V00035F1
Genuine swing motor with all mounting hardware and seals included.
Compatible: Kobelco SK200-8, SK210-8, SK200-8S, SK210-8S, SK200-10, SK210-10, SK220-10
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Part No: YN15V00037F1 / YN15V00037F2 / YN15V00037F3
Replaces: GM38VB
Genuine new travel motor for the SK200-8 generation.
Compatible: Kobelco SK200-8 and more
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Part No: YN15V00083F1
Replaces: GM38VC
Genuine new travel motor built to factory specifications.
Compatible: Kobelco SK200-10, SK220XD-10, SK220XDLC-10 and more
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A field guide to how this system is put together, what it does, and where it fails — written by the team that has supplied Kobelco parts since 2007.
Everything in this category has one thing in common — it is loaded, it rotates, and it is where a Kobelco excavator's operating hours actually land. The swing system lets the upper structure turn against the carbody. A hydraulic swing motor drives a swing reduction gearbox, which turns the pinion against the slewing ring (swing bearing) bolted between the upper frame and the undercarriage. The travel system moves the machine: a travel motor on each track, with its own reduction gearbox, brake and relief valve, fed oil through the swivel joint at the centre of the upper structure. Under the whole machine sit the undercarriage components — idler shafts and bushings among them — that carry the weight while it moves.
The swing gearbox and the travel final drives are the same idea at different scales: a hydraulic motor feeding a planetary reduction set, with a parking brake that is released hydraulically and applied by springs. That shared architecture explains why so many faults present identically on both — slow rotation, brake drag, oil weeping from the drain plug or the shaft seal, and a growing noise that operators describe as a grinding or a whine that changes with rotation speed rather than with engine speed.
Swing and travel failures are rarely sudden. The usual sequence is a slow oil leak from a shaft seal or the drain plug that goes unattended, followed by a drop in oil level, then gear and bearing wear, and finally either a seized reduction unit or a swing brake that will not release. Measuring the oil that comes out of a swing gearbox tells you where you are in that sequence: clean oil with a metallic sheen means early wear and a seal and bearing job; oil with visible chips or a strong burnt smell means the gear set and the bearings are done and the unit should be exchanged.
The list below covers every swing, travel and undercarriage part we hold in Guangzhou, including swing motors, travel motor assemblies, travel motor blocks and swash plates, ball guides, slewing rings, swing reduction assemblies, relief valves and the undercarriage consumables. Because these units are heavy, we quote them with crating and confirm the freight method at the same time as the price.
Each row is a fault pattern reported by operators in the field, the part that actually causes it, and what to replace at the same time so the repair holds.
| Operator reports | What is actually wrong | What to replace |
|---|---|---|
| Swing starts and stops with a bang, machine cannot hold position on a slope | Swing brake not fully releasing, or a failed swing motor relief valve allowing oil past instead of holding the upper structure. | Check swing brake release pressure first, then the swing relief valve. If the brake is dragging, renewal of the brake plates is required; on higher-hour machines the whole swing motor assembly is usually the better answer. |
| Oil weeping from the swing gearbox drain plug or around the pinion shaft, oil level dropping | Shaft seal or plug seal failure, frequently accompanied by a blocked breather. A blocked breather pressurises the housing and pushes oil past a healthy seal. | Renew seals and clear the breather before assuming internal damage. If the drained oil is clean, a seal and bearing job restores the unit at a fraction of exchange cost. |
| Grinding or rhythmic whine that varies with rotation speed, not engine speed | Pinion, ring gear or planetary gear wear inside the swing reduction or travel final drive, normally with bearing degradation behind it. | Drain and inspect the oil for chips. Where chips are present the reduction assembly should be exchanged rather than repaired — see the swing reduction and travel motor entries in the list below. |
| One track will not move, or moves only in one direction | Travel motor relief valve stuck open, or internal leakage past the travel motor block and swash plate. Occasionally the brake piston has not released. | Confirm brake release pressure, then check the travel motor relief cartridge. If the motor is leaking internally the swash plate, motor block and ball guide set is usually the repair route — all three are listed below. |
| Machine pulls to one side while tracking straight, tracks do not hold on a slope | Travel motor internal leakage on one side causing unequal speed, or a worn undercarriage idler shaft and bushing allowing the track frame to shift. | Compare case-drain flow between the two travel motors to identify the leaking side. Renew the idler shaft and bushing at the same time if track alignment has been disturbed. |
| Slewing ring noisy, machine rocks when swinging, grease extruding from the bearing seals | Slewing ring raceway or ball wear, or a pinion that has been running dry against a worn ring with poor backlash. | Measure backlash and inspect the raceway before ordering. Slewing rings are a major component — send photographs of the gear teeth and we will advise whether adjustment or replacement is the correct route. |
Tonnage class, the engine and hydraulic platform each model uses, and what we typically hold for it.
| Machine | Class | Engine & hydraulic platform | In stock for this model |
|---|---|---|---|
| SK130-8 / SK140-8 | 13-14 t | Mitsubishi D04FR · Kawasaki K3V63/K7V63 | Swing reduction units and slewing rings for the compact frame |
| SK200-8 / SK210-8 | 20-21 t | Hino J05E · Kawasaki K3V112 / K7V125 | Swing motors, swing reduction gearboxes and travel motor assemblies |
| SK220-10 / SK250-8 | 22-25 t | Hino J05E · Kawasaki K7V125 | Travel motor swash plates, travel motor blocks and relief valves |
| SK260LC-8 / SK260-10 | 26 t | Hino J05E · Kawasaki K7V125 | Swing motor seal kits, travel motor ball guides and gear pumps |
| SK330-8 / SK350-8 | 33-35 t | Hino J08E · Kawasaki K5V140 | Travel motor assemblies, final-drive gears and travel relief cartridges |
| SK350-9 / SK380-10 | 35-38 t | Hino J08E · Kawasaki K5V140 / K7V140 | Swing reduction assemblies, travel motor blocks and swivel joints |
| SK460-8 / SK480-8 | 46-48 t | Hino P11C · Kawasaki K3V180 | Heavy swing motors, larger travel motor assemblies and slewing rings |
| SK500XD / SK550-10 | 50-55 t | Hino P11C · Kawasaki K5V200 | Swing reduction gearboxes, travel motor components and idler shafts |
Tonnage follows the Kobelco model number: the digits after SK give the operating weight in hundreds of kilograms, so an SK250 is a 25-tonne class machine and an SK350 is a 35-tonne class machine. Short-radius SR variants use the same engine and hydraulic families as their standard counterparts, with different mounting hardware.
The prefix families you will see on a Kobelco parts diagram for this system, what they mean, and real numbers from our own inventory as examples.
| Prefix / format | What it tells you | Examples from our stock |
|---|---|---|
| M5X · M2X · GM series | The hydraulic motor model families used on Kobelco swing and travel drives. The number identifies displacement; the suffix identifies the brake and the reduction configuration. | Swing Motor M5X130 · Travel Motor GM38VC · Travel motor block |
| Rotation / reduction code | In a swing reduction or travel final drive number, the digits encode reduction ratio and housing generation. Two units that look identical but carry different ratio codes will rotate at different speeds. | Swing Reduction Assembly · Reducer · Travel Motor Assy |
| LC05 / LC15 / LC22 / LC52 | Kobelco part family used for swing and travel components — reduction parts, swivel joints and centre joint assemblies. | LC05P00043S032 · LC15V00003F2 · LC52S00012P1 |
| YN57V · YN22V · YN30V | Valves and control hardware on the swing and travel circuits, including swing brake release and two-speed travel solenoids. | YN57V00012F1 · YN30V00080F1 · YN22V00002F1 |
| ZB / ZB50 / ZB90 series | Slewing ring and bearing-related Kobelco numbers, and the assembly numbers that accompany them. | ZB50HLJJ · ZB90HLJJ |
| LP / LQ / YY | Undercarriage and hose group families used on the track frame and on the travel circuit lines. | Idler Shaft · Arm Bushing · YY52V01006P1 |
A Kobelco part is frequently identified by more than one number: the Kobelco catalogue number that appears on the parts diagram, and the original manufacturer number stamped on the component itself. Send us either and we will return the full interchangeable list, including supersessions, before you order.
The ten lines we hold in the greatest quantity right now, with live part numbers and model coverage. Quantities are updated from our Guangzhou warehouse.
| Part number | Description | Fits | In stock |
|---|---|---|---|
| YN52F02796P1/YN52F02330P1 | Swivel Joint Center | Kobelco SK-series | 48 |
| LC12B02199P1 | Arm Bushing | SK350-10 | 20 |
| YN22E00193F5 | ECU Controller | Kobelco SK-series | 7 |
| LC22E00336F8/LC22E00323F8 | ECU Controller | SK350-10 | 5 |
| C2162420488601/LC15V00023S042 | Travel Motor Ball GUide | 601, 624 | 4 |
| C2259321450501/LC22V00006F1 | Travel Motor Relief | Kobelco SK-series | 4 |
| YN15V00077F1/YN15V00055F1/YN15V00035F1 | Swing Motor | SK200-8 | 3 |
| C2162122059801 | Travel Motor Swash | 621 | 3 |
| VA32F2303402 | Idler Shaft | D06FR | 2 |
| LQ15V00031F5/LQ15V00020F1 | Travel Motor Assy | SK250-8 | 2 |
Every swing & travel system line we hold in Guangzhou, listed by part number with its current quantity. 17 part numbers, 108 pieces on the shelf. Click any line for photos, interchangeable numbers and machine fitment.
What we need from you to ship the right part first time — and the mistakes that cause returns in this category.
Drain the oil and look at it. Clean oil with only a faint metallic sheen means the gears and bearings are still serviceable and a seal and bearing job will restore the unit. Oil carrying visible chips, or oil with a strong burnt smell, means the gear set has been running with degraded or low oil and the reduction assembly should be exchanged. Send photographs of the drained oil and we will give you a straight answer before you commit.
On most Kobelco SK machines the two travel motors are the same base unit but are handed by their port blocks and plumbing, so they must be ordered as left and right. A motor fitted to the wrong side will either not receive oil correctly or will release its brake at the wrong moment. Always tell us which side you need.
The travel brake is held by springs and released hydraulically, so a creep means either the brake is not holding or oil is passing through the relief valve or the motor. Check brake release pressure first — if it is present at neutral the brake is being told to release and the fault is in the control circuit. If release pressure is correct at neutral, the brake plates or the motor internal leakage are the cause.
Yes. The idler shaft and its bushing locate the front of the track frame, and once the bushing wears the frame can shift, which shows up as uneven track tension, rapid edge wear on the track links and a machine that pulls to one side. Renewing the shaft and bushing is inexpensive compared with the track and undercarriage damage that misalignment causes if it is left.
Swing motors and travel motors typically fall in the range where air freight is still viable for a single unit, while slewing rings and complete swing reduction assemblies almost always ship by sea freight because of weight and diameter. We crate every unit, supply a packing list, commercial invoice and certificate of origin, and can arrange fumigation where the importing country requires it.
Yes. The swivel joint sits at the centre of the upper structure and carries oil to the travel motors, so it is involved in most travel faults. It is listed in our hydraulic category and we normally quote it alongside travel motor work when testing shows cross-port leakage.
