Oil leak from magneto

[Decampbelljr]

A seam in my magneto Is damp with oil. Is this engine oil, or is my mag starting to run dry? It’s a dual mag, so a catastrophic failure is always a worrisome thought.

 

[Salty]

Could have come from anywhere. Jmo

 

[Dan Thomas]

The magneto's shaft seal is leaking if the oil is coming out of the magneto's case seam. Don't fly it if it's doing that. Could burn the points out any time. There isn't supposed to be oil in the mag. If the seep is at the gasket where the mag is clamped to the engine, it's probably just a bad gasket. Mag might also be loose, another no-fly condition.

 

[Magman]

As Dan said ; either way you have a problem.

A 172XP ( TCM IO-360 ) having first Inspection done. Both Bendix mags were filled up with oil. The “ Garlock” Shaft Seals did not have a Spring installed that would keep a tight seal on the Shaft. There was a SB stating that engine should have the Seal with the Spring. I’ve wondered if Crankcase Pressure was a factor.

There are gaskets that are round with with no provision for Stud holes.
There are also gaskets with “ears “ that have the stud hole provision.

The other portion of Dan’s reply can be caused by an improper gasket. D- mags use a gasket that is round with no “ ears”. Installing the mag using a gasket with. “ears” could result in the hold-down clamps having incorrect torque thst may allow the mag to loosen.

Using a round “ no ears” gasket on a mag install that has Studs can result to a bent or cracked flange.

When you have the mag reinstalled assure you have a new Impulse Spring.