FOREWORD
The marine gearbox GW series manufactured by Hangzhou Advance Gearbox Group Co., Ltd, the People’s Republic of China, has been approved by the classification societies such as ABS, LR, GL, CCS etc. with good selling athome and abroad.
Thanks to their compact design and wide matching range, GW gearboxes’rated input speed is 400 ~ 1800 r·min-•, ratios2:1 ~ 6: 1 and rated transmission capacity ( N/n ) 0.257 ~ 9.25 kW / r·min-1.
GW gearboxes have 6 series, each of which has 10 models. The GWC, GWD, GWS and GWH have the function of reverse and reduction, and the GWL and GWK without reversing function. Input and output shafts -can be arranged coaxial or offset ( vertically, horizontally or diagonally ) . The gearboxes have adapted to combined design, and all running parts have been carefully designed and machined to the highest standards for less wasted fuel, smooth operation which can be fitted to most engine models.
Gearbox controller can be selected pneumatical or electrical operation with manual emergency control device. Gearbox and engine are connected by a highly flexible coupling which may be ordered on request. In generally a stand-by pump set should be prepared. When fitting to the engine, please refer to the main transmission data and the instructions in the manual. For special requirements, contact with sales and design departments.
A thorough understanding of this manual result in lengthy and satisfactory service from the gearbox, please carefully read the manual before putting the gearbox into operation and install, operate and maintain according to stipulated requirements in the manual.
Description of GW Series Gearbox
Marine Gearbox CW series cover six models. There are the GWC, GWD, GWS, GWH reverse reduction gears and the GWL and GWK reduction gears (without reversing function). The six models differ as follows :
The GWC reverse reduction gear has a primary stage, a reduction stage and a reverse stage. Input and output are coaxial and have same sense of rotation.
As the GWD model, the GWS reverse reduction gear has no primary stage, hut a reduction and a reverse stage.
Input and output are vertically offset andhave opposite sense of rotation.
The GWL reduction gear “‘Ithout reverse function corresponds to the GWC model in that it has a primary and a reduction stage.
Input and output are coaxial and have the same sense of rotation.
The GWD reverse reduction gear has no primary stage but a reduction and a reverse stage, either one of the clutch shafts is driven directly. Input and output are diagonally offset and have opposite sense of rotation.
The GWH reverse reduction gear, as GWD and GWS, has a reduction and a reverse stage, but no primary stage.
Input and output are horizontally offset and have opposite sense of rotation.
The GWK reduction gear has no reverse function and is of single stage design.
Input and output are vertically offset and have opposite sense of rotation.
Instructions
General Information
The gearbox i s delivered without oil.
The gearbox is coated with anti-rust oil inside, which is valid for six months when stored in a dry warehouse with moderate temperature.
The gearbox is painted on the outside, and the flange, shaft end and the surface of the flange plate on the outside of the gearbox are coated with anti-rust oil
The joints of the compressed air pipe, oil pipe and water pipe to be connected during on-site installation have been sealed with flanges or plugs.
The pipes and joints that connect or replace the gearbox must be carefully pickled and cleaned before assembly.
The direction of rotation is shown by an arrow.
If the gearbox is stored in the open air, it must be covered with a tarpaulin or a roof.
Our factory will not be held responsible for any unauthorized disassembly of the gearbox.
Maintenance
Daily: Check oil level.
Tum gap-type filter in the switch line 2一3 times.
Check the gearbox for leakages.
Check the oil pressures and temperatures.
Monthly: Clean the gap-type filter.
Clean the lubrication oil filter.
Check the remote control operation.
Check oil for water contact.
Yearly: Check all exterior screw connections.
Check the protection covering of the sea water cooler if used.
Oil change: Under normal service conditions, the first oil change must be after approximately 250 working hours.
Further oil changes must be completed after approximately 2000 service hours, however, not longer than 12 months.
In special conditions consult a mineral oil company.
Before filling with new oil, in accordance with the enclosed lubricant specifications, the gearbox must be cleaned with flushingoil.
Trouble-Shooting
- 1.Overheating
- 2.Lack of oil pressure
- 3.Oil leakage
- 4.The engine stalls during reversing:
- 5.The propeller does not reach the corresponding speed of the motor.
- 6.The propeller does not stop turning in "Neutral"
- 7.Gearbox noise
Possible cause: | Remedy: |
| Oil level is too high | Correct oil level |
| Lubricating oil pressure too low (insufficient cooled oil) | Re-set operating oil pressure to the lowest permitted value |
| Gearbox is overloaded | Reduce input power |
| Operating oil pressure is too low (clutch is slipping) Excessive pump pressure | Regulate operating pressure (see 2-stage valve) Clean the filter |
| Oil does not flow back from the outer bearing sides Bearings damaged | Installation of end covers or seal covers in such a way that the oil can flow back |
| Seal too tight | Replace damaged bearings |
| —— | Loosen |
| ——END—— | |
Possible cause: | Remedy: |
| Wrong direction of rotation | Alter engine rotation or gearbox rotation direction |
| Filter obstructed | Clean filter |
| Oil level too low | Refill with oil and trace cause of oil loss |
| The viscosity of the oil is too low | Change to an oil conforming to the ” recommended lubricants” |
| Oil temperature too high | See “Excessive gearbox temperature” |
| Suction pipe obstructed | Clean suction pipe |
| 2-stage valve is defective | Replace defective parts or the complete valve |
| Pump drive is defective | Renew the pump drive |
| Pump wear | Install new pump |
| Selector position is not correct | Adjust remote control operation |
| Wear of the oil supply | Renew oil supply |
| Quick release valve does not close | Clean quick release valve |
| ——END—— | |
Possible cause: | Remedy: |
| Drain plug is not tight | Replace the gasket and tighten drain plug Replace dipstick gasket and tighten |
| Dipstick connector not tight | Tighten all fittings |
| High pressure system leaking | Install a plate under the air-vent |
| Oil loss through the air-vent | Seal with new compound and tighten all bolts ：a) Renew sealsb) Install sealing cover in such a manner that the passage is free from the outer bearing side |
| Mating faces of the housings are not sealed | Replace the cooler stem |
| Leakage of the shaft seals | —— |
| Oil cooler is leakmg | —— |
| ——END—— | |
When switching over, the engine threatens to stall, at this manoeuvre the engine must be “caught” by fuel admission so that the power taken from the propeller will not be larger than the engine power at this moment.
Possible cause: | Remedy: |
| The idling speed is too low | Increase the idling speed |
| The operating pressure is too high, therefore, engagement is too quick | Reduce the operating pressure to normal value |
| The gearbox controller is defect (uncontrolled at flow to one clutch) | Replace gearbox controller |
| Clutch plates are damaged | Replace damaged clutch plates |
| The splines of the clutch are damaged | Re-work the splines or renew the part (check at critical speed ranges) |
| The release springs do not work | Clean the clutch. Replace the springs if necessary Renew damaged seal |
| Pistons of the clutch are jammed, seals damaged | —— |
| ——END—— | |
Possible cause: | Remedy: |
| Pressure gauge defect, higher pressure shown than in reality | Change pressure gauge and re-adjust oil pressure：1. Clean filter 2. Check the control stage |
| Control oil pressure too low | Adjust the remote control operation |
| Gearbox controller is not exactly in the “Ahead” position Gearbox controller defect | Replace controller |
| Damaged propeller shaft bearings | Replace worn bearings |
| Linings of the clutch in the incorrect sequence | Mount the clutch plates correctly |
| Clutch plates broken | Exchange damaged plates |
| Sealing rings of the clutch damaged | Replace with new sealing rings |
| The splines of the clutch are worn | Re-work the teeth or renew the part. Check the installation at critical speed ranges |
| ——END—— | |
Possible cause: | Remedy: |
| The vessel is still moving | Wait until it’ s at a complete standstill |
| The propeller is being driven by a current | Adjust the remote operation |
| Gearbocx controller is not directly on the ” stop position | Replace gearbox controller |
| Defect gearbox controller (uncontrolled oil to one clutch) | Renew clutch plates |
| Clutch plates broken | Renew seal |
| Seal damaged, sticking piston | Re-work the teeth or renew the part |
| Splines of the clutch damaged | Clean clutch and if required, replace spnngs |
| Release springs not working | —— |
| ——END—— | |
Possible cause: | Remedy: |
| Idle speed is within a critical range | Increase idling speed |
| Gearbox runs within the critical speed range. (The noise is not to be observed throughout the whole speed range) | Avoid running the gearbox continuously in the critical range |
| Input flange loose | Tighten the flange or replace when damaged |
| The oil level is too low (Suction noise of the pump) | Correct oil level |
| Suction pipe not tight. (Pump sucks in air) | Tighten all fittings on the suction line |
| Filter choked. (Excessive pump pressure) | Clean filter |
| Pump drive not in order. | Repair damaged parts, or replace |
| Gearwheel damaged or loose | Re-align-The whole installation |
| Extreme misalignment between engine and gearbox | Renew damaged bearings |
| Gearbox bearings damaged | Grind damaged area and, if necessary, replace the gear wheel |
| Gear wheels are damaged by foreign matter | Re-tighten the gear rims |
| The gear rims are loosened by overloading | Re-tighten the wheels |
| Gear wheels are loose on the shaft due to overloadmg Propeller damaged | Re-set propeller and eventually repair |
| Output flange is loose | Re-tighten the flange and replace if damaged |
| Extreme misalignment on the output side of the gearbox | Realign installation |
| ——END—— | |
Conclusion
The GW series marine gearbox is a critical component designed for durability, efficiency, and reliability in demanding maritime environments. While this guide offers a general overview of its maintenance practices and common fault diagnostics, it is important to understand that the specifics of operation, servicing intervals, and troubleshooting procedures may vary depending on the model and configuration. Therefore, for accurate and model-specific instructions, users should always refer to the official instruction manual provided with the gearbox upon delivery. This manual contains detailed guidance on installation, lubrication requirements, operational parameters, and routine maintenance schedules tailored to your particular unit.
In addition, our technical team is always ready to support you with any inquiries or special requirements you may have. For further clarification on technical specifications, spare parts, or service procedures, we encourage you to contact our sales or after-sales support personnel. They are equipped with the knowledge and resources to provide prompt and professional assistance, ensuring the optimal performance and longevity of your gearbox.
We are committed to helping our customers maintain the highest standards of operational safety and efficiency. Your satisfaction and the reliability of your marine equipment are our top priorities. Thank you for choosing the GW series marine gearbox—we look forward to supporting you throughout its lifecycle.
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