Sump bolts

[MarkCFI]

I am removing an engine pre-heater coil that is attached beneath the sump by 4 small hangers that are attached via the sump bolts.

The two forward bolts are easy to see and consist of a 7/16” bolt, washer and nut.

However the aft bolts (one at each corner) appear to thread directly in to the case. No washer and nut on top that I can see.

I just want to confirm that’s true and there is t some type of fastener or nut that I won’t be able to get to after I remove the hanger.

Are some of the aft bolts just threaded in to the case?

Lycoming o-320 D3G.

Thanks.

 

[Toobuilder]

Are some of the aft bolts just threaded in to the case?

Yes. They should be 1/4-20 (course thread)

 

[AZSteve053]

I am removing an engine pre-heater coil that is attached beneath the sump by 4 small hangers that are attached via the sump bolts.

The two forward bolts are easy to see and consist of a 7/16” bolt, washer and nut.

However the aft bolts (one at each corner) appear to thread directly in to the case. No washer and nut on top that I can see.

I just want to confirm that’s true and there is t some type of fastener or nut that I won’t be able to get to after I remove the hanger.

Are some of the aft bolts just threaded in to the case?

Lycoming o-320 D3G.

Thanks.

see attached Parts Manual
Fig 28 should be helpful

 

[MarkCFI]

Perfect

Thank you

 

[jrs14855]

Should be a flat washer and star washer at each location. Star washers should not be reused.