Transmission & Drivetrain Systems Flashcards
7 cards from real MTC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Transmission & Drivetrain Systems flashcards as text
On a jet-drive system, what component replaces the conventional propeller and shaft?
Answer: An impeller that draws and expels water for thrust
Jet drives use an engine-driven impeller to accelerate water through a nozzle, generating thrust without an exposed propeller or shaft.
What is the function of the shift interlock on a marine transmission?
Answer: Prevents shifting above a preset RPM to protect the gearbox
The shift interlock prevents engagement of forward or reverse above a safe RPM threshold, protecting the clutch packs and transmission internals.
Which measurement determines whether a propeller is correctly matched to an engine's WOT RPM range?
Answer: Engine RPM at wide-open throttle with the correct load
The propeller is correctly pitched when the engine reaches its rated WOT RPM range under normal load, ensuring it operates in its power band.
A cavitating propeller most often results from:
Answer: Air entrainment or low pressure on the blade back face causing vapor bubbles
Cavitation occurs when local pressure on the propeller blade drops below vapor pressure, forming and collapsing bubbles that erode the blade surface.
What is the standard torque specification approach when reassembling a propeller nut?
Answer: Torque to manufacturer specification and install a cotter pin through the castle nut
The propeller nut must be torqued to spec and secured with a cotter pin through the castle nut and shaft hole to prevent loosening under reverse loads.
When inspecting a stern drive bellows, a technician should look for:
Answer: Cracks, tears, hardening, or collapse that could allow water intrusion
Failed bellows allow water into the gimbal housing, which can flood the bilge and cause corrosion of drive components.
The 'slip' in a marine transmission refers to:
Answer: Incomplete clutch engagement causing speed differential between input and output
Transmission slip occurs when clutch packs do not fully engage, allowing the input shaft to rotate faster than the output shaft and wasting engine power as heat.