since 1940

Failure to change pitch or rpm in Lycoming or Continental aircraft engine

 2. If rpm fails to increase but will reduce: low oil pressure.

 3. If rpm change in both directions is sluggish: Excessive friction in hub mechanism.

 4. Newly-installed governor has wrong direction of rotation, or has bypass plug in wrong hole.

 5. Transfer-collar distress on Continental engines will cause sluggish or erratic propeller operation.

 6. Internal engine oil leak on Lycoming engines. With Lycoming engines you need to check main bearing clearance and rear plug in center of crankshaft for leaks. Remove propeller governor. There's a passage that goes down to the center of the front main bearing. The big hole indexes to the oil transfer tube which goes to prop governor. Take a differential pressure tester and with a rubber end push against passage. Apply 40 pounds in and as oil blows out of bearing you will see the secondary gauge come down. After 15 or 20 seconds you want to see 5 pounds or more. If the bearings will not hold 5 pounds you have an unacceptable leak. Turn propeller as you do the test. Limits are 5 to 20 psi. This is a quick and easy test to do after engine assembly at overhaul. 

 7. H-35 Bonanza with O-470-G engine modify front main bearing per Continental Service Bulletin M58-1 dated February 3, 1958.

A31 Vengeance WWII Recognition silhouette

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Disclaimer: sacskyranch.com contains abundant information relating to aircraft maintenance. The information provided  is not intended to supercede or supplement the F.A.A. approved  maintenance and/or operator’s manuals. Those F.A.A. approved manuals must be utilized when performing maintenance and/or operating aircraft.