Decreasing NR may be accompanied by a drop in transmission oil pressure of how many psi or more?

Decreasing NR may be accompanied by a drop in transmission oil pressure of how many psi or more?

• A. 5 psi
• B. 7 psi
• C. 9 psi
• D. 10 psi

Answer: (D)

When NR decreases, the rotor is slowing down and the transmission hydraulic system undergoes a transient change in demand and pump flow. The oil pressure can momentarily sag as the system responds to this deceleration. A drop in transmission oil pressure of 10 psi or more during NR decay is considered significant and outside normal transient variation. This threshold helps you recognize when the decrease in rotor speed is accompanied by a concerning loss of lubrication pressure, signaling a potential issue with the oil supply, pump, relief valve, or related components that should be investigated.

When NR decreases, the rotor is slowing down and the transmission hydraulic system undergoes a transient change in demand and pump flow. The oil pressure can momentarily sag as the system responds to this deceleration. A drop in transmission oil pressure of 10 psi or more during NR decay is considered significant and outside normal transient variation. This threshold helps you recognize when the decrease in rotor speed is accompanied by a concerning loss of lubrication pressure, signaling a potential issue with the oil supply, pump, relief valve, or related components that should be investigated.