Rocker Cover Screw Retention

[0TreeLemur]

The rocker cover machine screws on my O-360 loosen over time.   Similarly, after recent annual I noticed that the screw in #3 cyl that retains the dog house and the MAP line had fallen out.  The dog house wasn't removed at annual.   Can some grade of loctite help with this?

[philiplane]

blue loctite will do the trick

[A64Pilot]

I would use blue loctite, do NOT use red. I would suspicion that possibly the gaskets are compressing over time, but blue loctite should work and do no harm.

‘Anti sabotage lacquer AKA slippage mark wouod tell you if one has moved on inspection.

[RLCarter]

Replace the lock washers and torque them, don’t over tighten them or you will warp the rocker cover.

[N201MKTurbo]

The rocker cover screws have built in lock washers. If they lost their bite, they should be replaced.

https://www.aircraftspruce.com/catalog/eppages/rockerboxscrews-lyc.php

STD-1925

[RLCarter]

Just now, N201MKTurbo said:

The rocker cover screws have built in lock washers. If they lost their bite, they should be replaced.

https://www.aircraftspruce.com/catalog/eppages/rockerboxscrews-lyc.php

STD-1925

Interesting, pretty sure I replaced only the lock washers on mine..... 

[0TreeLemur]

3 minutes ago, N201MKTurbo said:

The rocker cover screws have built in lock washers. If they lost their bite, they should be replaced.

https://www.aircraftspruce.com/catalog/eppages/rockerboxscrews-lyc.php

STD-1925

Winner! Do you know, are these screws also the same as the ones that hold the dog house to the cylinders?  My engine has a mix of different machine screws.   That missing one that also holds the MAP line at Cyl #3 really bothered me.

[RLCarter]

26 minutes for the answer, MS rocks

[N201MKTurbo]

38 minutes ago, 0TreeLemur said:

Winner! Do you know, are these screws also the same as the ones that hold the dog house to the cylinders?  My engine has a mix of different machine screws.   That missing one that also holds the MAP line at Cyl #3 really bothered me.

They should be the same screws that go into the cylinders above the rocker covers, or anything where sheet metal  is attached to the engine with 1/4 20 screws.

[0TreeLemur]

26 minutes ago, 0TreeLemur said:

Winner! Do you know, are these screws also the same as the ones that hold the dog house to the cylinders?  My engine has a mix of different machine screws.   That missing one that also holds the MAP line at Cyl #3 really bothered me.

Ordered.

[ArtVandelay]

Might want to get prop balanced if you have screws coming loose.

[Hank]

1 hour ago, ArtVandelay said:

Might want to get prop balanced if you have screws coming loose.

Or schedule a psych eval . . . . . 

[MooneyMitch]

Possibly loose screw is the sitting in left seat!!  

[RLCarter]

1 hour ago, Hank said:

Or schedule a psych eval . . . . . 

Wonder how many of us would score we’ll?

[Hank]

5 minutes ago, RLCarter said:

Wonder how many of us would score we’ll?

Score!!

What is a good score? Sheldon often says, "I'm not crazy. My mother had me tested."

[1964-M20E]

49 minutes ago, Hank said:

Score!!

What is a good score? Sheldon often says, "I'm not crazy. My mother had me tested."

You just have to be less crazy than the one giving you the test.

 

 

[MooneyMitch]

56 minutes ago, 1964-M20E said:

You just have to be less crazy than the one giving you the test.

 

 

That certainly has merit !

[Guest]

I’m not sure how successful blue Loctite will be.  Many cylinder head temps will exceed its operating range.  New screws with new lock washers and proper torque work.

Clarence

[A64Pilot]

I don’t think that part of the head gets that hot, I say that as over 300F might cause the oil to coke, and it doesn’t. 

‘Might put a thermocouple on one to see

[Hank]

1 hour ago, A64Pilot said:

I don’t think that part of the head gets that hot, I say that as over 300F might cause the oil to coke, and it doesn’t. 

‘Might put a thermocouple on one to see

Why not look at your CHT gage? Shut down, wait 5-10 minutes, turn in the Master and see if it's absorbed any additional heat with the cooling airflow missing.

[PT20J]

Why do screws come loose? Vibration coupled with insufficient torque. How can you get insufficient torque? Give the screws a twist every so often. The gasket will compress a little more each time until eventually it looses resiliency. Same thing with hose clamps. Sometimes it is best to leave well enough alone. 

Skip

. 

[MB65E]

I have not lost a rocker screw since switching to silicone gaskets. 
-Matt

[0TreeLemur]

23 hours ago, N201MKTurbo said:

The rocker cover screws have built in lock washers. If they lost their bite, they should be replaced.

https://www.aircraftspruce.com/catalog/eppages/rockerboxscrews-lyc.php

STD-1925

BTW- there is no reason why this information can't be in a FAQ section if MS had one.   There is nothing subjective or controversial about it.

[N201MKTurbo]

Just now, 0TreeLemur said:

BTW- there is no reason why this information can't be in a FAQ section if MS had one.   There is nothing subjective or controversial about it.

I think the Lycoming parts manual is already posted in the downloads section.

[0TreeLemur]

5 minutes ago, N201MKTurbo said:

I think the Lycoming parts manual is already posted in the downloads section.

You're saying that instead of a giving MS participants easy access to non-controversial information, let's make them hunt for it or start a new thread.  I don't get it.