Crankshaft Axial Clearance

[Geeman]

When I grabbed my prop the other day to move the plane it felt like the prop moved a bit more relative to engine than normal. Anyone know what the axial clearance spec is for o-360-a4m. Solid crank fixed pitch.

[Don Jones]

If it is the fore and aft movement of the crank (thrust) the spec is .009 - .016 according to the repair manual.

[tim2542]

Also, that tolerance mentioned is very deceiving when felt on a large object like a propellor or flywheel. It might feel like you could measure it with a tape measure, but when you indicate it, will probably find it within specs.
Tim

[Geeman]

Thanks. I was thinking it would be about .010" but was not sure. I am going to check it. Probably ok. Thanks for info.

[DanBaier]

I think you would have a filter full of aluminum if it were out of spec.

What I seem to see the most is people push the aircraft into the hangar using the prop. When they grab the prop to pull on it, there's kind of a "thunk" and you can feel the movement. But it's not what it seems. The thrust surface (front) of the crankshaft is banging on the front end of the case and there's plenty of mass there to make the noise.





Don't be surprised if you have difficulty getting a really good measurement (with the engine assembled).

Dan