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Parts Catalog for Twin Disc MG5075A Marine Transmissions
Plate Kit For Twin Disc MG5075A Marine Transmission
Gasket Kits For Twin Disc MG5075A Marine Transmission
Introduction to Storage and Long-Term Preservation
Proper storage and long-term preservation of the Twin Disc MG5075A marine transmission are essential for maintaining its functionality, preventing corrosion, and ensuring a smooth restart after storage. Whether the transmission is being stored for seasonal downtime, extended vessel inactivity, or as a spare unit, following proper storage procedures will prevent component deterioration and unnecessary repairs.
This guide outlines best practices for preparing the MG5075A transmission for storage, protecting it against corrosion and moisture, performing periodic maintenance during extended storage, and restarting it safely after long-term inactivity.
1. Preparing the Transmission for Storage
Before storing the Twin Disc MG5075A transmission, it must be properly prepared to prevent issues such as rust, fluid degradation, and seal hardening.
A. When Should a Transmission Be Prepared for Storage?
✔ Seasonal downtime – Boats that operate seasonally should store transmissions properly during the off-season.
✔ Extended inactivity – If a vessel is out of service for 6 months or longer, proper storage preparation is necessary.
✔ Backup or spare transmissions – Stored units should be preserved to ensure they are ready for future use.
B. Steps to Prepare the Transmission for Storage
1. Draining and Flushing Old Fluids
✔ Drain all transmission fluid completely to remove contaminants.
✔ Flush the system with clean oil to remove residues and debris.
✔ Fill the transmission with fresh oil to prevent corrosion.
✔ Drain and replace hydraulic fluid in the clutch system to avoid moisture buildup.
✔ If transmission will be stored for longer than a year, consider using storage oil (lightly lubricated with rust-inhibiting additives).
2. Cleaning the Exterior and Internal Components
✔ Wipe down the exterior of the transmission with a degreaser to remove oil and dirt.
✔ Blow out any remaining oil or fluid from hydraulic lines using compressed air.
✔ Inspect the bell housing and shaft seals for leaks and debris.
3. Protecting Seals and Bearings
✔ Apply seal conditioner to prevent drying and cracking.
✔ Coat bearings with light grease to reduce moisture exposure.
✔ Insert moisture-absorbing packets inside the storage area to keep humidity levels low.
4. Disconnecting Transmission from the Engine (If Storing Separately)
✔ Secure all mounting bolts and couplings in labeled containers.
✔ Cap off all fluid ports and hydraulic connections to prevent contamination.
✔ If storing with the engine attached, place a plastic sheet over both to protect against dust.
By properly preparing the transmission for storage, you prevent fluid degradation, corrosion, and mechanical wear, ensuring it is ready for future use.
2. Protection Against Corrosion and Moisture
Moisture is one of the greatest threats to stored transmissions, leading to rust, oxidation, and premature wear. Proper corrosion protection ensures that internal components remain free from damage.
A. Common Causes of Corrosion in Stored Transmissions
✔ Humidity and condensation – Stored units in coastal or high-humidity environments are prone to rust.
✔ Improperly sealed components – Unsealed transmission ports allow moisture intrusion.
✔ Inadequate lubrication – Dry bearings, seals, and gears increase the risk of corrosion.
✔ Contaminated fluid – Water or dirt in the oil accelerates oxidation.
B. Corrosion Prevention Methods
1. Applying Protective Coatings
✔ Use corrosion inhibitors inside the transmission before sealing it for storage.
✔ Spray the exterior with rust-preventative lubricant.
✔ Apply a thin coat of anti-rust grease on exposed metal parts.
2. Using Moisture-Control Measures
✔ Store transmissions in a temperature-controlled environment.
✔ Use desiccant packets or silica gel inside the storage area.
✔ Cover the transmission with a breathable tarp to prevent dust while allowing air circulation.
3. Choosing the Right Storage Location
✔ Indoor storage is preferred to minimize temperature fluctuations.
✔ If stored outdoors, cover with a waterproof tarp but allow airflow to prevent condensation.
✔ Place the transmission on wooden pallets or supports instead of directly on concrete to prevent moisture absorption.
Taking preventative measures against corrosion ensures that stored transmissions remain in peak condition for future use.
3. Periodic Maintenance During Extended Storage
Even when not in use, the Twin Disc MG5075A transmission requires periodic maintenance to ensure it remains in working order.
A. Recommended Storage Maintenance Schedule
| Task | Frequency |
| Check for leaks, rust, or fluid seepage | Monthly |
| Rotate the input/output shafts to prevent seal hardening | Every 3 months |
| Inspect storage environment for excessive moisture | Every 6 months |
| Replace desiccant packs and moisture absorbers | Every 6 months |
| Change oil if stored for over 1 year | Annually |
B. Steps for Periodic Maintenance
1. Rotating the Shafts to Prevent Seizure
✔ Turn the input and output shafts manually every 3 months.
✔ Apply a small amount of fresh oil to internal components before rotation.
✔ Listen for unusual noises, which may indicate developing rust or contamination.
2. Inspecting Seals and Gaskets
✔ Check shaft seals and gaskets for cracks or leaks.
✔ Reapply seal lubricants if seals begin drying out.
3. Replacing Moisture Control Materials
✔ Replace desiccant packs or rust inhibitors inside the storage area every 6 months.
✔ If using vacuum-sealed storage, check for air leaks in the seal.
Performing routine maintenance during storage prevents damage caused by extended inactivity, ensuring the transmission is ready for reinstallation.
4. Restarting After Long-Term Storage
After extended storage, the Twin Disc MG5075A transmission must be carefully restarted to ensure smooth operation and prevent mechanical damage.
A. Pre-Restart Checklist
✔ Inspect transmission exterior for signs of corrosion, leaks, or damage.
✔ Check oil levels and replace stored fluid with fresh oil.
✔ Reinstall hydraulic lines and ensure proper fluid circulation.
✔ Manually rotate the input shaft to verify smooth movement.
B. Refilling Fluids and Priming the System
✔ Drain old storage oil and refill with fresh transmission fluid.
✔ Prime the hydraulic system by manually pumping fluid through the lines.
✔ Check for fluid leaks around gaskets and hose connections.
C. Testing the Transmission Before Reinstallation
1. Bench Testing
✔ Mount the transmission on a secure test stand.
✔ Attach a hydraulic pressure gauge to verify proper clutch engagement.
✔ Shift between forward, neutral, and reverse gears to ensure smooth operation.
2. Reinstalling in the Vessel
✔ Secure mounting bolts and torque them to specifications.
✔ Connect electrical and hydraulic lines properly.
✔ Perform a sea trial under load to verify performance.
Restarting the transmission carefully and systematically ensures reliable performance after long-term storage.
Conclusion
Proper storage and long-term preservation of the Twin Disc MG5075A transmission prevent corrosion, fluid degradation, and mechanical wear.
Key Takeaways:
✔ Drain old fluids and replace with storage oil before long-term storage.
✔ Protect against corrosion and moisture using coatings and desiccant packs.
✔ Perform periodic maintenance to prevent seal drying and rust formation.
✔ Follow a structured restart procedure to ensure safe reinstallation.
By following these best practices, vessel operators and marine technicians can preserve the transmission’s integrity, extend its lifespan, and ensure trouble-free operation after storage.
Parts Catalog for Twin Disc MG5075A Marine Transmissions
Plate Kit For Twin Disc MG5075A Marine Transmission
Gasket Kits For Twin Disc MG5075A Marine Transmission
