🔍 Key Concepts

• Observe how device 1 is shaped and mounted around the shaft: does it look more like a gear/ring on a flywheel or like a smooth seal surface? • Look at device 2: is it part of a sealing arrangement, a protective cover (shrouding), or a small reference/indicator feature on the shaft? • Think about which pair of terms in the choices naturally go together as parts of the same functional assembly on a main engine crankshaft end.

💭 Think About

• If device 1 were a starting or jacking gear, what visual cues would you expect (for example, teeth, diameter, and position relative to the flywheel)? • If device 2 were a seal (lip seal) or shrouding, where would it sit in relation to the bearing housing and oil space, and what would it need to contact? • Which answer choice describes two parts that would logically be used together in the same job (starting/jacking the engine vs. keeping oil in and contaminants out)?

✅ Before You Answer

• Look closely at whether device 1 has gear teeth or flinger features—that will narrow down your options. • Check whether device 2 appears to touch the shaft (like a seal) or simply points at it (like an indicator). • Before choosing, ask: do these two terms reasonably describe what you SEE in the cross‑section, and do they sound like a matched pair commonly discussed together in engine-room practice?