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Broken Motor Mount 66'E


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So the engine went to Tulsa Wed.  Last weekend I took the nose gear apart and sent the truss assembly off to Lasar.  Today I started to sand and prep the motor mount tubes and was planing to epoxy paint them... but I found a broken tube!

Its clear this isn't a fresh break.  The tube was full of water and oil.  I suspect it cracked when it had a prop strike in 1998 and nobody noticed.  While I don't feel lucky, I guess I am lucky that we found the case crack in the engine and thus found this broken mount because it could have been bad if not addressed.  Its right below the passenger lower mount.

So now I need some recommendations on where to sent it for repair and overhaul.  Any suggestions?

UNADJUSTEDNONRAW_thumb_a8c2.thumb.jpg.655def505ba4c1f3bb626bc8eea9239c.jpg

 

IMG_2248.HEIC

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There is an AD that called for another tube to be welded around the existing tube. Your’s appears to be missing that weld. I would have another IA do an AD compliance check on the airplane. As for engine mount repairs. AWI is good but they wouldn’t return my calls earlier this year. Might check with Alan Fox for a used mount. 
-Matt

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17 minutes ago, MB65E said:

There is an AD that called for another tube to be welded around the existing tube. Your’s appears to be missing that weld. I would have another IA do an AD compliance check on the airplane. As for engine mount repairs. AWI is good but they wouldn’t return my calls earlier this year. Might check with Alan Fox for a used mount. 
-Matt

That' interesting. Thanks

I left a voicemail at AWI, Wag Aero and talked with Lasar.  Not sure who else to try.

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good catch, Nuke!
 

Hard to say what makes things crack...

But, that avoid extended operating in this range... is worth following....

+1 on sending to a welding house that is familiar with engine mounts...

I have had one engine mount lose contact with a bolt... leaving three bolts holding my O360 on the firewall...

 

Signs of an engine mount not doing its job properly...

  • Sometimes the engine sags... sometimes it doesn’t...
  • Sometimes the engine vibration changes... enough to form bubbles in compass...


Check the tube that was full of water... it may have a rust problem associated with it...

Engine mounts are critical to an airplane’s ability to fly... :)  If the engine falls off, gliding is going to be a challenge...

PP thoughts only, not a mechanic...

Best regards,

-a-

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Lasar came back and said they could do it. $1500 if it needed the two AD. It looks like one of the two have been done. I’ll likely send it to them. 
 

I found the AD mentioned above that wasn’t done. Says it was supposed to be done before 800hrs or during engine swing. It’s been swung 3 times before and it’s at 3800hrs. So boo to prior owner’s mechanics!  

sbm20-175-1.pdf

Edited by Nukemzzz
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You may find less vibration in flight after fixing it as now the rubber mounts are doing their "isolating of vibration" 

5 hours ago, N201MKTurbo said:

The annual I'm just finishing had items on the list that look like they haven't been touched in decades.

YUP we find stuff like that all the time.   And one wonder why the first annual by a new owner costs so much? "-)

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3 hours ago, ArtVandelay said:


I was amazed by the small size of the bolts holding the frame to the firewall, as compared to the bolts used in the engine mounts.

It’s quite a feat of engineering for Mooney, 4 bolts 1/4” in diameter.   Most Piper and Cessna products use 4-5 bolts which are 3/8” diameter.

Clarence

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16 hours ago, Nukemzzz said:

So the engine went to Tulsa Wed.  Last weekend I took the nose gear apart and sent the truss assembly off to Lasar.  Today I started to sand and prep the motor mount tubes and was planing to epoxy paint them... but I found a broken tube!

Its clear this isn't a fresh break.  The tube was full of water and oil.  I suspect it cracked when it had a prop strike in 1998 and nobody noticed.  While I don't feel lucky, I guess I am lucky that we found the case crack in the engine and thus found this broken mount because it could have been bad if not addressed.  Its right below the passenger lower mount.

So now I need some recommendations on where to sent it for repair and overhaul.  Any suggestions?

UNADJUSTEDNONRAW_thumb_a8c2.thumb.jpg.655def505ba4c1f3bb626bc8eea9239c.jpg

 

IMG_2248.HEIC 2.59 MB · 3 downloads

JB weld that sucker.... :)

 

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14 hours ago, Nukemzzz said:

Lasar came back and said they could do it. $1500 if it needed the two AD. It looks like one of the two have been done. I’ll likely send it to them. 
 

I found the AD mentioned above that wasn’t done. Says it was supposed to be done before 800hrs or during engine swing. It’s been swung 3 times before and it’s at 3800hrs. So boo to prior owner’s mechanics!  

sbm20-175-1.pdf

Good “catch” to be sure. I really appreciate your posting, and that you included the SB. It applies to my current situation (engine overhaul in process) AND the engine just happens to be off the mounts right now. I spent yesterday afternoon cleaning the firewall and removing obstructions on the engine mount before I was to begin sanding in preparation to re-paint it. But now I may have to go down a different path once I get back over to the plane to see if this SB has been complied with or not. Based on what I’ve seen so far, I’m betting on “not”. I owe you. 

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Yup, I've done the 3 bolt thing also. Pulling the cowling off and pretty sure my IA and I saw it at the same time. "This is why we do annuals" he said. Said a few hail Marys and ckd the torque and alignment on all of them. Luckily nothing got bent out of shape, but noticed a rub on the fiberglass lower enclosure that should have been my early wake up call.

Sent from my SM-G970U using Tapatalk

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14 hours ago, Moonbat said:

Good “catch” to be sure. I really appreciate your posting, and that you included the SB. It applies to my current situation (engine overhaul in process) AND the engine just happens to be off the mounts right now. I spent yesterday afternoon cleaning the firewall and removing obstructions on the engine mount before I was to begin sanding in preparation to re-paint it. But now I may have to go down a different path once I get back over to the plane to see if this SB has been complied with or not. Based on what I’ve seen so far, I’m betting on “not”. I owe you. 

Note there is a second one that requires the addition of corner braces. sbm20-192a-1.pdf

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I suspect that this isn’t noticed until annual time and that doesn’t often line up with engine rebuild time. I wouldn’t have thought to check for mount AD during and engine swing. Prior owners probably faced this situation. There was an “awe crap!” followed by “we will just keep an eye on it” statement to prevent another swing when they found they missed it later. 

Edited by Nukemzzz
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On 5/16/2020 at 2:51 AM, ArtVandelay said:


I was amazed by the small size of the bolts holding the frame to the firewall, as compared to the bolts used in the engine mounts.

Amazing how small the hardware is...

And sometimes what is included during the install...

The firewall often has carpet or sound deadening materials on it...

Make sure the soft materials don’t end up under the hardware... (even the factory has gotten this wrong a few times...)

PP thoughts only, not a mechanic...

Best regards,

-a-

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On 5/15/2020 at 7:07 PM, Andy95W said:

Send it to LASAR.  They will repair it IAW the Airworthiness Directive and it will be better than new for a reasonable price.  They've been doing it for 50 years.

Lasar now tells me that they don't have authorization to repair broken engine mounts and they recommend AWI.  I'm confused.

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34 minutes ago, MB65E said:

AWI lists an exchange for $1600 if I recall. 
However, Alan Fox May have one available. 
Where are you located? I know a few welders. 
-Matt

I'm in Columbus Indiana.  

I believe my IA is wanting the frame inspected as well since it was broken there may be other areas that have been over stressed.  He seemed to be specifically against sending it to a nearby welder.  

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1 hour ago, Nukemzzz said:

Lasar now tells me that they don't have authorization to repair broken engine mounts and they recommend AWI.  I'm confused.

They are a certified FAA repair station, which might limit what they're willing to do.   This is why some shops (e.g., Maxwell, iirc), don't become repair stations.   Any A&P can perform or supervise the repair.  Usually these days many A&Ps know a competent welding shop where they can spec a repair and supervise via inspection of the results.   I'd think the main thing in this case would be making sure it's jigged/aligned properly for the repair.

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3 hours ago, Nukemzzz said:

Lasar now tells me that they don't have authorization to repair broken engine mounts and they recommend AWI.  I'm confused.

When LASAR changed hands, they may have cut back on some of the services they offer.

AWI does quality work, at least for exhausts.  I imagine their engine mounts are probably really good too.

I would give them a call, make sure they have and understand the AD and Service Bulletins (I bet they’ve done a few before).  While they have it, they should strip and inspect it for cracks like your IA said.  Then you can paint it before installation. 

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