Charles K Posted August 24 Report Posted August 24 Reaching out to the community for some friendly advice on the level of concern and follow-on action. Background: 1981 M20J (IO-360) went in for annual service with some avionics upgrades early this year. Every item found on the report was approved for repair/fix. A/C flew from MX to home station, about a 4+30 flight with one stop for fuel. One item was a crankshaft seal leaking, removed and replaced the crankshaft seal and prop o-ring—common fix from what I can research, done. After arriving home, I noticed a few streaks on the passenger side windshield, which appeared lubricant-based. Noted and cleaned the windshield as the prop was dry. Fast forward two short flights later, followed by another 4+00 flight, the streaks appeared on the windshield again, prop still dry. Findings: The spinner was removed yesterday to check for any apparent issues. On removal, there was a random installation of long and short bolts on the spinner and the inner spinner assembly. The aft spinner bulkhead appears to be installed 180° out from the markings of a #1 and #2 on the assembly—minor streaks from the prop and engine crankshaft attachment point. Spinner had a small lubricant (grease) transfer relative to prop #2. Action: I cleaned streaks and the spinner transfer, reinstalled the proper bolt pattern, and will perform a ground run and flight, then recheck for streaks or lubricant transfers. Concern: The aft spinner bulkhead is the balancing attachment point for added weight. Can it be rotated 180° without removing the prop? Or does it even matter?
N201MKTurbo Posted August 25 Report Posted August 25 If you have balance weights, it does matter. When I R&R a prop, I put som sharpie marks on them when I take them off so they go on the same way. 1
Yetti Posted August 25 Report Posted August 25 Well you do have to take the prop off to replace a 1 piece crank shaft seal
cliffy Posted August 26 Report Posted August 26 Was the "leak" from the crankshaft/prop flange area or from one of the prop blade to hub seals? In hot weather one "might" see small specks of oil from a blade/seal interface - not really a problem The aft spinner bulkhead can only be removed with the prop off. One could always just get a dynamic prop balance done to avoid removing the prop IF the leak is NOT between the crankshaft/prop flange or the crankcase seal. 1
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