pilotyoung
Well Known Member
I purchased my RV-13 last February with 338 hours on it. It now has 432 hours on it. This summer I started noticing that when I reduce power from cruise, around 4400 down to about 3800 I get a vibration. I think it started after I complied with the Service Bulletin on the cracks in the front of the propeller hub. I hear the vibration more that I feel it. Two other pilots who have ridden with me also think it is from the propeller or gear box. The engine runs smoothly at cruise and at idle.
About a month ago I rechecked the front hub for cracks, and found none, and reset the blade angles at 71.4 and 71.3. The vibrations continued. This last week I replaced the soft engine isolators with the new ones from Van's and replaced all the springs on the muffler.
When I flew the aircraft, it still has the vibrations. Today I rechecked the blade angles and they are still 71.4 and 71.3. I checked the torque on the bolts and they are fine. I looked all over the engine for anything loose that could be vibrating and didn't find anything.
The propeller was dynamically balanced at 105 hours.
So I am asking for ideas, suggestions on what might be causing these vibrations. Has anyone else experienced vibrations like this?
Thanks.
About a month ago I rechecked the front hub for cracks, and found none, and reset the blade angles at 71.4 and 71.3. The vibrations continued. This last week I replaced the soft engine isolators with the new ones from Van's and replaced all the springs on the muffler.
When I flew the aircraft, it still has the vibrations. Today I rechecked the blade angles and they are still 71.4 and 71.3. I checked the torque on the bolts and they are fine. I looked all over the engine for anything loose that could be vibrating and didn't find anything.
The propeller was dynamically balanced at 105 hours.
So I am asking for ideas, suggestions on what might be causing these vibrations. Has anyone else experienced vibrations like this?
Thanks.