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Ruh-Roh

Posted: Fri Jun 14, 2019 10:28 pm
by Steve
Bad news today. Looks like I'm in for an extended down time and significant decrease in my liquid assets. Yesterday I flew my airplane and then changed the oil. I was also planning to install my ADS-B setup. Well, when I removed the suction screen, this is what I found:
DSCN5825a.jpg
My A&P/IA and I spent the next hour or so poring over the engine assembly and parts manuals. The only part like this in the engine is a 10/32 set screw which secures the propeller governor idler shaft. Without this set screw the shaft can move back and forth in the engine case, and apparently has led to a couple of engine failures. Lycoming put out an AD addressing this in 2015, but it only applied to aerobatic engines, not the IO-360-M1A:
2015-02-07.pdf
(46.96 KiB) Downloaded 149 times
There is a Service Bulletin which specifies an inspection procedure to determine if the set screw is loose:
SI1560 Set Screw Inspection.pdf
(169.16 KiB) Downloaded 151 times
and a new procedure to install the set screw to prevent loss:
SI1343C Set Screw Installation.pdf
(453.96 KiB) Downloaded 128 times
So, I pulled the prop off today. Here are two photos of us doing the inspection:
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You can see how the shaft is easily pulled forward using a magnet in the second photo. It should not move at all. We conferred with Lycoming Technical Support, and (of course) they said that the engine has to be split. So now, I have to decide how to approach the issue. My engine has about 725 hours, starts and runs great, has good compressions, and has had good oil analyses since new. On the other hand, it is 18 years old. My choices are:

1) Pull the engine and have my mechanic split the case, inspect, replace the set screw (and anything else he finds wrong). I trust him, and he gives a two year warranty on his engine work. This would be the cheapest option, although not necessarily the quickest.

2) Buy an exchange engine from Lycoming (either new, overhauled, or rebuilt). If they have an engine in stock, it could be shipped out, and meanwhile we could dismount the old engine and prep the airframe for the new one. Of course, unless I take the new option, I don't know what the overhauled or rebuilt engine has been through (prop strike, number of rebuilds, etc.).

3) Remove my engine and ship it to Lycoming to be overhauled or rebuilt. Longer downtime, plus twice the shipping cost (once to get the shipping crate here, once to get the engine back to Lycoming, again here for the new engine, and then the empty crate back).

So any guidance/advice would be appreciated. I also wanted to make the Group aware of this issue, and I would recommend doing the inspection SI if you ever have the prop off your aircraft.

Steve

Re: Ruh-Roh

Posted: Sat Jun 15, 2019 12:11 am
by Rich
One could construe the AD to apply to our engines (mine is ser #L-30286-51A).

"This AD applies to all Lycoming Engines wide deck aerobatic reciprocating engines that have either an ''A'' or an ''E'' at the end of the serial number (e.g., L-12345-51A, or L-12345-51E) and are equipped with a front-mounted propeller governor. Affected reciprocating engine models include, but are not limited to Lycoming Engines: <followed by a list>"

In light of your experience it probably should and may come to apply to the M1A and probably others. Your recommendation is a good one.

I kind of lucked out (if you can call it that). I had my engine worked over for an unrelated issue in 2015 and what do I see in the log but a reference to the AD and a note that says "Set screw was installed in accordance with paragraph (e)".

But that doesn't help you. I don't know about Lycoming, but I'm told by my mechanic that all the high-rep engine shops are "slammed" with work. The shop that did my engine (Premier, in Troutdale) is one such highly-regarded shop and they apparently have a backlog of something like 16 months. If you have confidence in your guy to split the cases and remedy it locally, I suspect that will be your shortest-downtime option. And probably lowest cost.

Re: Ruh-Roh

Posted: Sat Jun 15, 2019 4:02 pm
by BRS
It's basically 10K to split and change the bearings. At this point a 'rebuild' seems to make sense. Too bad it happened in peak flying weather. If it were mine, I'd give Ly-Con a call. Not only could they put your engine back in good order they might be able to get you a few extra ponies out of it as well.

Re: Ruh-Roh

Posted: Sat Jun 15, 2019 5:02 pm
by Steve
In South TX, where I live, it is almost always peak flying weather...

Re: Ruh-Roh

Posted: Wed Jul 10, 2019 11:32 pm
by Steve
Just to keep everyone up to date on the engine pull...

I was away the last two weeks, so no work done. This week I worked on it about one and a half days, took the exhaust and and all of the accessories off the engine. I have a few oil lines to disconnect at the rear of the engine, then it can come off the airplane. I didn't have large enough crescent wrenches at the hangar, so that is for another day. Unfortunately, my mechanic is going on a cruise next week, so it will be fits and starts...

I have been checking my "spares" drawer, and there are some hardware items I won't need to buy for the reinstallation, I had some extra exhaust gaskets, nuts, etc. Still making an Aircraft Spruce list, though. I'll post periodically, to let all vicariously "enjoy" the process along with me.

Steve
DSCN5912.jpg
Looks a little "naked"...

DSCN5916.jpg
Everything laid out for reinstallation (someday)...

Re: Ruh-Roh

Posted: Mon Jul 15, 2019 3:20 pm
by vontresc
What's the quoted turnaround time on the overhaul? When we had ours done this spring Poplar Grove had about an 8 week backlog :-(. On the up side as we are relatively close we got to tour the shop, and even saw our engine fully disassembled.

It has been running great since.

Re: Ruh-Roh

Posted: Mon Jul 15, 2019 3:29 pm
by Steve
6-8 weeks. The shop is at my airfield, so I will be able to keep an eye on the progress, and even help (disassembly only). Since the engine has less than 750 hours on it and no other problems, I decided not to overhaul. We are just splitting the case and repairing the issue (plus new bearings, and anything else that the inspection discovers).

Steve

Re: Ruh-Roh

Posted: Sat Jul 20, 2019 9:58 pm
by Steve
So the engine is off - only took about 30 minutes.
IMG_3032.jpg
IMG_3038.jpg
IMG_3040.jpg
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Now the hard part begins :(

Re: Ruh-Roh

Posted: Sun Jul 21, 2019 1:53 am
by Colin
Engineering is often so beautiful. Great photos of it, too.

Re: Ruh-Roh

Posted: Sun Jul 21, 2019 1:18 pm
by Steve
Yes, they sure fit a lot of stuff in a small space...

Steve