Photo of top of IO-360

[HRM]

Anybody have a photo of the top (looking down) of an IO-360 showing the pushrod tubes? The parts diagram is exploded and I am curious as to how the spring clip works.

[Piloto]

Hope this helps.

José

[HRM]

4 hours ago, Piloto said:

Hope this helps.

Jose, thank you!

That said, now I am worse off than before because I really don't see what the spring does. The tube on my #2 exhaust is pulled away from the head, but where did it go? Does the spring keep the tube tight against the head end and if gone, let's say, the tube pushes down into the camshaft end?

I can't get to the hangar until next week to look and this is driving me nuts.

[Guest]

The wave spring at the crankcase pushes the pushrod tube and seal against the cylinder head, while at the same time it pushes the seal against the crankcase.

Clarence

[tony]

6 hours ago, HRM said:

Jose, thank you!

That said, now I am worse off than before because I really don't see what the spring does. The tube on my #2 exhaust is pulled away from the head, but where did it go? Does the spring keep the tube tight against the head end and if gone, let's say, the tube pushes down into the camshaft end?

I can't get to the hangar until next week to look and this is driving me nuts.

you must have oil all over the place then....

[HRM]

3 hours ago, tony said:

you must have oil all over the place then....

That is an understatement, visit this thread.

[HRM]

3 hours ago, M20Doc said:

The wave spring at the crankcase pushes the pushrod tube and seal against the cylinder head, while at the same time it pushes the seal against the crankcase.

 

So if the spring broke off or came off or slipped, the tube at the crankcase end could move into the crankcase and pull the head end out, like this:

[kmyfm20s]

 

 

Here is is a couple pictures with and without the pushrods in place. It is easy to see the new spring clips in the top photo.

[HRM]

53 minutes ago, kmyfm20s said:

Here is is a couple pictures with and without the pushrods in place. It is easy to see the new spring clips in the top photo.

Thank you! Yes, I am finally seeing how this works. The spring pushes against the tab. If the springs aren't safety wired, they could rotate so the bump in the spring would no longer contact the tab and thus slip out on the head end.

[MB65E]

I've never seen them safetyed. Not a bad idea, but they should have  a good detent on them. If they don't something's wrong. 

-Matt

[Guest]

8 hours ago, HRM said:

So if the spring broke off or came off or slipped, the tube at the crankcase end could move into the crankcase and pull the head end out, like this:

Exactly, all the is required is to rotate the spring to engage the tabs on the pushrod tube.  In the past the springs were safety wired together, but it's not the norm now.

Clarence

[Bob_Belville]

[tony]

Mine are safety wired to each other in pairs.  

[HRM]

On 10/5/2017 at 4:26 PM, M20Doc said:

In the past the springs were safety wired together, but it's not the norm now.

But why? Seems like it would help keep this sort of thing from happening.

[MB65E]

Interesting-I didn't know yours slipped off until now. Fee free to safety them, but I'd be more concerned about why it slipped. Might be an install or other issue. They do start to leak every now and then. One thing I've done is to spin the tube around to give it a new contact seat. Usually helps to control  seepage. 

-Matt

[Guest]

The only time that I've seen them come loose is when the were installed incorrectly namely the points on the tube were not locked in the notches on the wave spring.

In the past cylinder base nuts were also safety wired together, history have shown that it's not required.

Clarence

[HRM]

Mystery solved...or even more mysterious (wondering what caused this). 

[Marcopolo]

1 hour ago, HRM said:

Mystery solved...or even more mysterious (wondering what caused this).

  I'm very interested in what the push-rod inside that tube looks lie, I hope that there was something on the outside that may have worn into the tube, but I'm afraid it may have been the push-rod inside trying to find a way out.

 

Fingers Crossed!

 

Ron

[MB65E]

That tube is super thin to start with. Top it off with 50 years of vibration. Maybe it was dented or scratched from years ago and the vibration finally cracked it. Also if someone tried to torque the tube to spin it to brake loose a seal, that might have cracked it too. 

Good thing is there are many of them available. Hopfully the pushrod is fine. It's steel and the tube is aluminum, it might be ok. 

-Matt

[HRM]

2 hours ago, Marcopolo said:

I'm very interested in what the push-rod inside that tube looks lie, I hope that there was something on the outside that may have worn into the tube, but I'm afraid it may have been the push-rod inside trying to find a way out.

 

Fingers Crossed!

 

Ron, I flew her for three hours before discovering this issue, so I am thinking the pushrod is OK.

As Matt pointed out, years of vibration--in fact, her 52nd birthday was Monday! I am wondering if they are the original tubes, they certainly look ragged. Anyway, new tubes soon and I should know the condition of the rod this weekend. The other factor is that #2 always runs hot, like most C&E's with the doghouse. 

If the rod is OK this will be another testament to the integrity of the IO-360.

[N201MKTurbo]

5 hours ago, HRM said:

Ron, I flew her for three hours before discovering this issue, so I am thinking the pushrod is OK.

As Matt pointed out, years of vibration--in fact, her 52nd birthday was Monday! I am wondering if they are the original tubes, they certainly look ragged. Anyway, new tubes soon and I should know the condition of the rod this weekend. The other factor is that #2 always runs hot, like most C&E's with the doghouse. 

If the rod is OK this will be another testament to the integrity of the IO-360.

I wouldn't rush and buy 8 new tubes. The new ones will have the crimped spring bumps. The old ones have the brazed bumps which I think are a lot better.