Sooner or later, every outboard motor owner faces the need to maintain the bottom of the unit, and water, sand and foreign objects often cause wear and tear of seals or damage. transmissionRemoval of the gearbox is the basic procedure required to replace the osteoils, check the condition of the gears or eliminate oil leaks.
Many beginners are afraid to start this work on their own, for fear of disrupting settings or damaging expensive nodes. However, with a basic set of tools and a clear understanding of the sequence of actions, the procedure is quite affordable even in garage conditions, the main thing here is to take your time and follow the technology so as not to encounter problems with reverse assembly.
In this article, we will discuss in detail the process of dismantling the bottom of the engine, paying special attention to the nuances that are often silent in official manuals. climactic You need to pay attention to the engine after repair to go long and reliable.
Workplace preparation and necessary tool
Before disassembly begins, you need to ensure safe and comfortable working conditions. The outboard motor must be securely fixed on the stand or transom of the boat to prevent it from falling or shifting during the unscrewing of heavy bolts. It is best to work on a flat surface covered with clean rags, since spilled oil can stain the floor, and the lost small part can roll in an unknown direction.
To successfully complete the task, you will need a standard mechanic kit, supplemented by several specific devices. Lack of the right tool can lead to slicing of the bolt faces or damage to the thread, which will turn a simple repair into a long epic on drilling the fastener.
- 🛠️ A set of carob and cape keys, as well as heads (including an extension cord and a rattle) for unscrewing flange fastening bolts.
- 🔨 Rubber bladder or wooden bar for careful separation of the mating surfaces without damage to the metal.
- 🧴 Capacity for draining old transmission oil and a funnel for pouring new.
- 🧽 Clean rags and degreaser to clean surfaces before assembly.
We need to focus on cleanliness, and we need to focus on getting abrasive particles inside. crankcase It's not acceptable to have mud on the surfaces of the coils, and it can cause slip bearings to fail or cause premature wear on the cuffs, which will lead to re-repair in a short time.
Drain of oil and primary diagnosis of the condition
The first step before removing the gearbox directly is to drain the transmission oil, which not only releases the internal cavity, but also allows for a primary diagnosis of the gearbox condition by the appearance of the fluid, and the color and consistency of the oil can tell us about the inside of the gear before it is opened.
Unscrew the bottom plug of the drain hole and let the oil drain completely into the prepared container. If the liquid is milky, this indicates that water has entered the water, which indicates a malfunction. sludge Or micro-cracks in the body, and the presence of metal chips on the magnet of the bottom cork is also a wake-up call.
Keep the magnetic plug clean – even a small amount of metal dust can provide important information about the degree of wear of gears and bearings.
In normal condition, the oil should be transparent or slightly yellowish, without the smell of burning. If you find an emulsion, before assembly, you will definitely need a thorough washing of the internal cavities with kerosene or a special solvent to remove the residue of water and prevent corrosion of parts.
⚠️ Attention: If the leaked oil shows large metal particles or gear fragments, further operation of the engine without major transmission repairs is strictly prohibited.
Dismantling gearshift traction
One of the most important and often ignored operations is to properly disconnect the gearshift traction. It is errors at this stage that most often result in the motor not turning on the gear or operating with high noise after assembly. The switching mechanism requires precise synchronization of the position of the rod and the scene.
First, you need to access the thrust junction with the gearbox shaft. Depending on the model of the motor, this can be a separate screw on the side or the need to remove the rample control cover. Before unscrewing the locking element, it is strongly recommended to mark the shaft and thrust housing to restore the original position when assembled.
When the fastener is loosened, carefully pull the thrust aside. Don't put too much effort into not bending the thin metal stem. If the thrust is not relieved, check if the locking screw has jammed in the thread - penetrating lubricant is sometimes required.
Nyances of traction settings
The precise adjustment of the gear shift traction is made only after the gearbox is fully assembled and the gearbox is installed in place. The pre-label serves only as a guide, but the final adjustment of the gear gear engagement and forward must be performed manually, checking the ease of inclusion and the absence of extraneous sounds.
Disconnecting the gearbox from lower unit
The gearbox attaches to the lower unit tube by means of several bolts that pass through the flange, which are often exposed to corrosion and high pressure, and can be stuck to the body, and it is recommended to be heavily treated with penetrating lubricant, such as WD-40, before unscrewing, and left for 10-15 minutes.
Use a head of the appropriate size to unscrew the bolts evenly diagonally, which will help avoid flange distortion and damage to the gasket. If the bolts do not lend themselves, do not use excessive force that can break the hat - it is better to repeat the treatment with chemistry or gently warm the connection with a building hair dryer, avoiding fire on rubber seals.
Once all the bolts are unscrewed, the gearbox doesn't always fall down by itself, but it's held back by residual pressure, sealant or corrosion on the docking surfaces, and it's important not to use the screwdriver as a lever, inserting it into the gap between the lower unit and the gearbox, because that's guaranteed to damage the landing planes.
- 🔍 Check the pad: if it broke during removal, it must be replaced with a new one.
- 🔧 Check the condition of the slate connection of the shaft - it should not be bullies.
- 🧹 Clean landfill surfaces of old sealant and oxides before installation.
☑️ Checklist before removing the gearbox
Removal process and inspection of gears
To remove the gearbox, take it with both hands and swing it from side to side while pulling it down. If the knot doesn't go, you can gently tap a rubber knob on the side walls of the crankcase, but never hit a lower unit pipe. A sharp jerk can damage the shaft's shaft slits or the oment.
Once the gearbox is separated, you can access the main transmission nodes, visually inspect the reverse gear and the forward gear, and the teeth should not have chips, or production or "steps," and these defects indicate that you need to replace a pair of gears, because worn parts are not possible to pair with new ones.
Pay special attention to the condition of the needle bearings on which the gears rotate. They should sit tightly, without backlash, and their surface should be smooth. If the bearing has traces of corrosion or is rotated in the landing place, its replacement is mandatory.
| Component | Normal. | Signs of malfunction | Action. |
|---|---|---|---|
| Scooterney. | Smooth teeth, no bullies. | Slips, step wear | Couple replacement |
| Bearings | Tight landing, smoothness | Luft, corrosion, noise | Pressing new ones |
| Salmon | Elastic rubber | Cracks, suffocation | Mandatory replacement |
| The sealing ring | Integrated, no tears. | Flatting, cuts. | Replacement |
If you plan to change the glands, now is the time to remove them from the seats. Use a thin screwdriver or a special detacher, trying not to damage the landing surfaces of the shaft. New glands are recommended to be lubricated with lithium lubricant or oil before installation to facilitate installation and initial work.
The quality defect of the removed gearbox avoids re-disassembly after the season. Change all seals and suspicious bearings immediately, without waiting for their complete failure on the water.
Assembly and installation of the gearbox in place
The assembly is done in reverse removal order. Before installing the gearbox on lower unit, make sure that the gearshift shaft and the main shaft slits are properly mated. Apply a thin layer of manufacturer-recommended sealant on the gasket or use a new gasket without a sealant, if required by the design.
Carefully put the gearbox on the lower unit pipe, making sure that the switch thrust hits the groove of the backstage. Flanc bolts twist cross-cross, gradually increasing the force to ensure that the planes fit evenly. The puff moment must meet the specification for your motor model - usually this value is indicated in the manual.
Once the body is fixed, you need to adjust the thrust of the switch. Set the gearbox lever to neutral and align the thrust tags. Check the ease of switching from neutral to front and back. The mechanism should be clearly activated, with a characteristic click, without jamming.
⚠️ Attention: Incorrect adjustment of the thrust of the switch can cause the gear to be partially engaged, which will cause rapid wear of the teeth ("licking") and the characteristic howling when the engine is working.
The final step is to pour fresh transmission oil. Fill the gearbox through the bottom hole until the oil starts to flow out of the top one. This ensures there is no air traffic jams. Twirl the plugs by replacing the O-rings, and wipe the body dry.
How to check the quality of the assembly
After you've assembled and poured the oil, let the engine stand for 10 to 15 minutes, put a clean sheet of paper under the gearbox, and if there's no oil stains on the paper, it's restored to the right tightness and you can run the test.
Frequently Asked Questions (FAQ)
How often should you change the oil in the gearbox?
Manufacturers recommend changing the oil in the gearbox once a season or after every 100 hours of operation, however, if you notice the emulsion (white oil) earlier, you need to make a replacement immediately, first eliminating the cause of the water intake.
Can I use normal engine oil instead of transmission oil?
No, you can't. The gearbox has hypoid gears that require special anti-bully oils, and the normal engine oil doesn't provide the necessary protection for the gears, which will cause them to collapse quickly.
What if the flange bolts are boiling and not unscrewed?
Do not use excessive force. Treat the joints with penetrating lubricant several times at intervals. You can use the heat carefully, but with caution. In extreme cases, the bolts will have to be drilled and cut new threads or pick up a repair fixture of larger diameter.
Do I need to lubricate the shaft slits before installing the gearbox?
Yes, the slate connection of the screw shaft and the gear slit is recommended to be lubricated with water-resistant lubricant (for example, lithium), which will prevent corrosion and facilitate the removal of the gearbox in the future, and also protect from moisture entering the lower unit pipe.