So the repair did NOT implement the SI? Do I have that correct?
FFS. I need a new hobby.
- Thread starter Jim K
- Start date
So the repair did NOT implement the SI? Do I have that correct?
True. Without a complete teardown this time, it will likely still be indeterminate.
The only way to access that shaft is to split the case. I was actually surprised to see how much metal was chewed off that cap compared to how much metal WASN'T in my oil filters.
Io540k1g5d
That turned out to be the vacuum pump shaft seal. Solved by throwing the vacuum pump in the ****it bucket.
Daleandee
Final Approach
- Joined
- Mar 4, 2020
- Messages
- 6,874
- Display Name
Display name:
Dale Andee
Carolina warranty ... it breaks in half, you get to keep both pieces!
The narrow deck 540s had no retention mechanism other than the cap itself and I haven't seen one of the narrow deck caps worn like yours is. I haven't seen everything though, and presumably Lycoming had a reason for wanting a more substantial means of retention. Apparently try #1 didn't work the best either so here we are.
Perhaps you or your mechanic should call Lycoming and discuss this with them to see if they have an opinion on why this has happened twice.
Last edited:
MBDiagMan
Final Approach
Welcome to one of the many hobbies that involve mechanical contrivances. This sort of thing is what comes along with flying, racing, motorcycling and other hobbies. If you’re not one to weild wrenches from time to time and develop a mental list of the things you’ve learned about your particular plane from such experiences, then maybe some other hobby would indeed be more enjoyable for you. These sorts of things come with the territory.
RyanShort1
Final Approach
I feel ya. Two significant gear issues in one of our planes in 8 years - and not for a lack of throwing money at keeping it fixed.
So here's some awesome borescope shots my mechanic took today
This is the new shaft. Correct part number with a recess to accept the set screw. It slipped right out with a magnet.
Set screw. Clearly an attempt at staking, but nothing like described in the service letter.
Inside of the bore. Set screw was either not installed deeply enough or (more likely) backed out due to not being staked correctly, which allowed the tip to shear off. No way of knowing how long it's been like that, but it's clearly been a while.
About 800
Well, he put the new parts in. "We don't follow service instructions" seems like a damn strange thing to say when you're installing new parts referenced in a service instruction.
I told the mechanic who was R&Ring the engine to make sure Chris referenced the SI in his log entry. I thought he did, but my mechanic tells me the log entry references a different SI. Obviously I didn't check it closely. Mea Culpa.
No. It's a my home base in the care of my home mechanic though. It's in good hands.
Gee thanks. I've never owned anything with an engine before
I agree.
I also think there’s a difference between a warrantee and fixing a botched repair. In other words, I can agree with his short warrantee, but not with not standing behind his work. But I’m not a lawyer.
texasclouds
En-Route
Arkansas guarantee, if it breaks you keep both parts
Are you sure the tip actually got sheared off?
That was painful to say.
Looking at the set screw, as well as the Lycoming SI. To me it doesn't appear the set screw to be sheared...maybe worn down, but I'm not seeing wear marks on the shaft. Looking at the Lycoming diagrams it doesn't appear it had a tip, at least not one that id be expecting. I'd be expecting a full dog point set screw and based off the SI looks they used a cone point.
I'm not too fond of the fix Lycoming used and I don't think I'd pin all the blame on the guy doing the repair... There doesn't appear to be a ton of material on the set screw to have a real positive bite on the shaft if I'm interpreting it correctly. And personally I'm not a fan of staking, intentionally damaging threads and notoriously inconsistent. Now what do you do with those threads that have already been blasted with a hammer?
But I will blame him for his lack of customer service and the "we don't follow service instructions" quote. Unacceptable. If I was him it would have been "oh ****!! I'm glad you're ok! Can you send those pictures over and I'll call Lycoming to see what went wrong"
That was painful to say.
Looking at the set screw, as well as the Lycoming SI. To me it doesn't appear the set screw to be sheared...maybe worn down, but I'm not seeing wear marks on the shaft. Looking at the Lycoming diagrams it doesn't appear it had a tip, at least not one that id be expecting. I'd be expecting a full dog point set screw and based off the SI looks they used a cone point.
I'm not too fond of the fix Lycoming used and I don't think I'd pin all the blame on the guy doing the repair... There doesn't appear to be a ton of material on the set screw to have a real positive bite on the shaft if I'm interpreting it correctly. And personally I'm not a fan of staking, intentionally damaging threads and notoriously inconsistent. Now what do you do with those threads that have already been blasted with a hammer?
But I will blame him for his lack of customer service and the "we don't follow service instructions" quote. Unacceptable. If I was him it would have been "oh ****!! I'm glad you're ok! Can you send those pictures over and I'll call Lycoming to see what went wrong"
Last edited:
- Joined
- Mar 15, 2016
- Messages
- 4,898
- Display Name
Display name:
Ari
That pedal-powered combine sounds awful. No wonder your harvest takes so long.Gee thanks. I've never owned anything with an engine before
No, I'm not sure of anything. Looking at those pictures and the SB, you know exactly as much about it as i do now.
I haven't seen the shaft in person, but it looks to me like there's a hole in it intended to receive the conical tip of the set screw. Seems like that would be plenty to prevent the shaft from turning...if it can't back out.
WRT the peening...i agree that it seems like a sloppy fix, but obviously the consequences of that shaft getting loose are dire. What happens at overhaul? I guess you send the case to divco.
I agree it should be enough to keep it from turning provided it can't back out. And it does look like they failed to stake it per the SI. I'm just not convinced a better stake would have prevented this. With the type of set screw they they used it really wouldn't take much to back out enough to be catastrophic. The hole looks slightly egged, which confirms it was rocking on the point. Eventually the rock wore that point down. Surprised they didn't use a thread like they use on the exhaust studs to keep it from backing out. Male threads thicker than female threads
The Lycoming set screw part number...and the dog point I would have expected
The Lycoming set screw part number...and the dog point I would have expected
455 Bravo Uniform
Final Approach
Is there a reason there is not a thru-hole in the shaft, or one all the way through to the other side, so that it’s not dependent on a little nub of a set screw? Did the original spring pin setup involve both sides of the shaft?
The staking doesn’t look like the staking in the instructions. Looks like both the threads in the hole and set screw need to be deformed to hold. And whatever thread locker properly applied, if applied at all.
I’d still want to get FAA and Lycoming involved for data sake.
The dual mag servicing cost thing and this idler gear shaft are but a couple examples of stuff a regular guy wouldn’t ever know when buying a plane. It seems outside the realm of buyer-beware. Hidden cost of ownership for mere mortals, years after pre-buy.
The staking doesn’t look like the staking in the instructions. Looks like both the threads in the hole and set screw need to be deformed to hold. And whatever thread locker properly applied, if applied at all.
I’d still want to get FAA and Lycoming involved for data sake.
The dual mag servicing cost thing and this idler gear shaft are but a couple examples of stuff a regular guy wouldn’t ever know when buying a plane. It seems outside the realm of buyer-beware. Hidden cost of ownership for mere mortals, years after pre-buy.
Sorry you're dealing with this man, at least it wasn't in flight this time.
If it makes you feel better I'mannoying informing my A&P about your mechanical misfortunes every annual.
If it makes you feel better I'm
Right, the shaft was obviously rocking for a while and chewed the point off the set screw. "Sheared" was a poor choice of words as that would infer an instant failure.
I think the conical screw tip makes sense for the fact that it can self center in the hole. Remember that Lycoming is asking mechanics to drill & tap this hole in the field. It's not a precision operation. There can't be much force on that shaft. The original spring pin design (which i have been unable to find a picture of) worked MOST of the time. Seems like the set screw is massive overkill, *IF* it can't back out through vibration. Hence the staking.
QFT. I'll definitely send him the pictures now that we have them. I'm not going to hold my breath though. Thinking of like to get Lycoming's thoughts on it as well, but don't know where to start. @Ted you still know anybody over there who'd be interested in this?
I never did contact the fsdo or file a service difficulty report last time. I assumed a competent shop would find and follow the SIs. My mechanic seems to be able to. There apparently should be an AD on this to ensure field overhauls and IRANs are done correctly.
Lindberg
Final Approach
I don't know anyone about the technical subject matter, but I'm the absence of an express warranty (or even if there was one), it might be worth your while to chat with an attorney about your rights here.
- Joined
- Feb 28, 2013
- Messages
- 1,724
- Display Name
Display name:
Warlock
Products and Completed operations case…if he’s insured probably has liability coverage for his work…I would be looking for a competent Products lawyer but the numbers and time may not work depending on the jurisdiction.
Believe me, I thought about it. He's damn lucky we caught it before it spit out the shaft again and I died in the resultant crash, because I think my heirs would have a pretty strong lawsuit at that point. Hopefully it would've just been me and not my whole family...
I suspect a lawyer would tell me that I don't have any, or much, damages as it stands, but IANAL.
I have set set screws on many shafts, both with holes and without. This appears to be a case of missing the hole, but setting the screw and staking it. If so, pounding the cap to stake the screw threads would tend to hammer the end of the set screw against the shaft, tending to decrease the tension , or flatten the point. Hours of vibration then caused slippage, and the wearing the parts.
I suspect an assistant assembled those parts, not an A/P. Our flying club had that problem several times, but the cost was not as high as yours, Jim.
Much sympathy, and after a talk with Lycoming, you may be able to afford an attorney. Get the real thing, not an assistant.
I suspect an assistant assembled those parts, not an A/P. Our flying club had that problem several times, but the cost was not as high as yours, Jim.
Much sympathy, and after a talk with Lycoming, you may be able to afford an attorney. Get the real thing, not an assistant.
Omalley1537
Cleared for Takeoff
- Joined
- Mar 13, 2015
- Messages
- 1,392
- Display Name
Display name:
Sean
Bit of a thread drift, but related…I follow an auto repair shop on YouTube. He regularly mentions the throwaway mentality of the auto-makers now. He showed an example of a late-model truck (less than 7 years old if memory serves) with a leaking transmission input seal. Other than labor costs, no problem, right? Wrong…you can’t buy the seal. Anywhere. Not the manufacturer, not aftermarket, not anywhere. His inquiry revealed that you can only buy the seal along with the entire transmission…12K please…Ugh! That sucks, Jim!
WRT “disposable society,” 6 months ago the shop told my wife, “you need a new engine.” Not an overhaul/reman/repair/whatever. Only option was new. (And yes, that was truly the only option.)
This week it’s, “you need a new transmission.”
At least our old airplane engines were designed and built to be repairable.
Oh…and we’re not doing the new transmission. We’re doing a new vehicle. Anybody need a 2016 Escape? Great condition, 238,000 miles, but only 10,000 miles on the engine.
He was able to engineer a solution to install a different vehicle’s seal and a spacer they made, but still…
Lindberg
Final Approach
You won't know if you don't ask. It looks to me like you have at least $20,000 in damages, maybe more. And there might be some mechanism for recovering a multiple of your actual damages. But you'd need to chat with a good lawyer in your state.
If you’ll look at the last photo of post #49, you’ll notice scoring below and to the left of the remains of the set screw point. That could have been caused by the tip that was sheared off.
I’m sure by now he’s acquired a couple of draft horses to pull it.
SixPapaCharlie
May the force be with you
- Joined
- Aug 8, 2013
- Messages
- 16,414
- Display Name
Display name:
Sixer
Sorry to hear this.
MauleSkinner
Touchdown! Greaser!
As my grandpa used to say,
The horse that farts will never tire.
The man that farts is the man to hire.
- Joined
- Mar 15, 2016
- Messages
- 4,898
- Display Name
Display name:
Ari
No way. He might not be very bright, but there’s no way he is dumb enough to own an airplane and draft horses.
Rcmutz
Cleared for Takeoff
Jim…. Really sorry to hear about what’s going on. Like you said, the good news is it wasn’t why you were flying.
Are those score marks I’m seeing in the last photo? Is that normal or caused by the tip of the set screw after it separated from the screw? (Just noticed Half Fast had the same thought)
Are those score marks I’m seeing in the last photo? Is that normal or caused by the tip of the set screw after it separated from the screw? (Just noticed Half Fast had the same thought)
Rcmutz
Cleared for Takeoff
If that was the case, I’d expect to see scoring on the shaft.
david.h
Pre-takeoff checklist
This right here is a major reason I switched hobbies to jetskis. I can turn my wrench on anything and no worries. But being stranded on a lake is significantly easier that at 500 feet with no good options.
Ted
The pilot formerly known as Twin Engine Ted
- Joined
- Oct 9, 2007
- Messages
- 30,005
- Display Name
Display name:
iFlyNothing
I haven't read the whole thread, but if you want to call someone at Lycoming, I'd start with the general tech support line (no idea the number). A few good folks still there who I know, but I'm not sure if there's anything they can really do to help you besides give you a list of service instructions/bulletins to make sure you follow.
- Joined
- Jun 13, 2008
- Messages
- 7,835
- Location
- Marietta, GA
- Display Name
Display name:
Drake the Outlaw
- Joined
- Oct 16, 2019
- Messages
- 6,165
- Location
- Atlanta / Marietta
- Display Name
Display name:
Vintage Snazzy (so my adult children say)
This is why I’m thinking about becoming an A&P now that I’m retired so I can do some of this work myself. Maybe on more critical items do it and pay a more experienced mechanic to review my work.
BRW, my new to me airplane that I got in June is in the shop now getting 3 cylinders rebuilt. Thought I had a solid pre buy. Maybe not that solid.
BRW, my new to me airplane that I got in June is in the shop now getting 3 cylinders rebuilt. Thought I had a solid pre buy. Maybe not that solid.
moparrob66
Pre-takeoff checklist
- Joined
- Mar 31, 2024
- Messages
- 249
- Display Name
Display name:
Moparrob
The two years spent becoming an A&P might be better spent on building an E-AB unless youre counting on going into business. Then you'll need insurance, business license(s), hangar space for dismantled aircraft waiting on unavailable parts, etc.
I don't know why but I read it as spring and pin. Not spring pin. The original part was a roll pin that went through the case. That hole for the roll pin was drilled out and tapped for a 3/16 long 10/32 set screw.
I honestly like the sound of a roll pin better. But that obviously didn't work either.
I would definitely be calling Lycoming Monday.
I honestly like the sound of a roll pin better. But that obviously didn't work either.
I would definitely be calling Lycoming Monday.
I did the exact same thing. I was talking to my mechanic about it this evening and he said "oh... you'd probably call it a roll pin". Duh. Apparently that's an aviation terminology thing.