Systems
Marine transmission service and drive system diagnostics
The transmission sits between a healthy engine and a boat that actually moves, and it gets overlooked in almost every maintenance schedule. I service marine gearboxes, sample and analyse the fluid, check shift operation and coupling condition, and look at alignment where vibration suggests it.
Nobody checks the gearbox until it slips
Transmission fluid is changed far less often than engine oil, and misalignment quietly destroys couplings, cutlass bearings and seals over a season. Vibration under way gets blamed on the propeller when the real cause is an engine that has settled on tired mounts.
What is included
- Transmission fluid and filter service
- Fluid sampling for laboratory analysis
- Shift linkage and actuator operation
- Coupling, damper plate and mount inspection
- Alignment assessment where vibration is present
- Oil cooler inspection for cross contamination
How it works
Service
Fluid and filter changed, with a sample retained for analysis.
Check
Shift operation, coupling condition, mounts and damper plate all get inspected while access is open.
Align
Where vibration or wear points to it, alignment gets assessed rather than assumed.
Marine transmission fluid analysis can reveal oil cooler cross contamination and clutch pack wear, and misalignment between engine and shaft is a common cause of vibration that is frequently misattributed to the propeller.
Related systems work
Marine Generator Service
Service, repair and load testing for marine generators, the system that keeps air conditioning and power alive at anchor.
Cooling System Service
Raw water and closed loop cooling service, flushing and repair, the system that causes most marine diesel overheats.
Heat Exchanger Service
Cleaning, pressure testing and repair of heat exchangers, aftercoolers and oil coolers fouled by salt water.
Marine Transmission Service: common questions
How often should transmission fluid be changed?
Follow the manufacturer interval, and treat annual as a sensible default. It is a small job that gets skipped for years at a time.
My boat vibrates at cruise. Is it the propeller?
It might be, but engine mount settling, coupling wear, cutlass bearing wear and shaft alignment all produce similar vibration. Checking alignment before repitching a propeller saves money.
Can transmission fluid tell you about the engine?
It can tell you about the oil cooler. Cross contamination between engine oil, coolant and gear oil shows up in fluid analysis and points straight at a failing cooler.
Tell me what the engine is doing
Describe the symptom on the phone and most of the time the problem is narrowed before I arrive. Surveys are booked around your sea trial date.