Prop failure - who pays?

[Sandy]

I hope all you deep thinkers will give me your opinion about this situation:

About six months prior to this event I had replaced my engine and done all the extra bank account drainers that go with it. I had the prop (McCauley) and governer overhauled and the engine mount tested at the same shop. Forty nine hours and about six months later the prop froze at full (coarse) pitch while I was away from home. It cost me over $1600 plus travel and time to have the problem corrected. The overhaul shop and McCauley were very sorry it happened but felt no responsibility for my expenses.Since then the overhaul shop has sent me a check for $320. No, we don't know why it failed. However there were "a few" bits of chromium in the hub - and chromium was high in my latest oil analysis - done during annual one hour after the incident - the filter was also changed during the repair and no metal was found in it. If this engine (FOH IO-360 A3B6) has chrome rings it's probably not a problem. Should I be stuck with this bill? and, does this engine have chrome rings?

I've omitted a lot of detail to keep this fairly short. Thanks for your thoughts.

Sandy

[TTaylor]

Sorry, unless the repair or work was under a warranty you are the one that pays the bill.   The only way you could potentially get some help is if you could prove that either the engine or prop overhaul were done negligently and caused the damage.  That is likely hard to prove.   All parts are subject to failure and even newly overhauled parts can have issues from years of use.

[MB65E]

Interesting they used chrome rings. I don't understand why they would use chrome rings. 

I can't keep it straight. Chrome rings in chrome Cylinders I think is bad? I bet you have chrome cylinders with standard rings. Chrome will flake, but seems strange it ended up in the propeller. 

I had a prop issue post overhaul. Complained about it, paid 500 to have the shop reseal it. Guess what, it didn't leak! Price to pay for such a fine performing machine!! Glad you were able to get home. Keep track of all of your oil analysis. 

Best,

-Matt

[RobertGary1]

40 minutes ago, MB65E said:

Interesting they used chrome rings. I don't understand why they would use chrome rings. 

 

Best,

-Matt

I'm pretty sure my new Lycoming engine I put in last year came with Chrome rings from the factory. 

-Robert

[MB65E]

Yeah, maybe they are all chrome. I've only heard of the conflict between chrome a few times.

-Matt

[Guest]

Chrome faced rings in Chrome cylinder bores won't make it off the test cell let alone into the air.

Clarence

[MB65E]

1 hour ago, M20Doc said:

Chrome faced rings in Chrome cylinder bores won't make it off the test cell let alone into the air.

Clarence

Thanks Sir!! 

Thats what I thought. What's the advantages of a chrome faced ring in a standard barrel? 

Are the standard Lycoming rings Chrome? I wasn't aware of the option. 

-Matt

[Cody Stallings]

Chromium or Cadmium in the propeller hub?

I could see Cadmium being a culprit.

[carusoam]

The prop Failing to low rpm is a bit odd.  The usual failure mode is low oil pressure in the hub and high rpm...

Any metal bits in the filter at oil change time?

Did you get any particular warranty with the Overhaul?

It's been a while since your last post, have you been actively flying your Mooney?

The usual bill payer is the owner.  Often an owner will pay extra for a warranty.  Sometimes they go to a big name shop that offers this as part of their service.  Sometimes parts may have a warranty from the manufacturer, but getting them installed may take work by the local mechanic that may not be covered.  Check you paperwork..?

If you can, can you post some JPI graphs?  They sometimes show a fingerprint of things going awry.  Often Mooney pilots will post an entire flight from start-up to shut down.  I suspect that you may have some CHT issues that will stand out to somebody with skills.

In this thread, you have received input from two of the best. A great Mooney mechanic and the best prop guy in the business...(understatements)  I am just a PP...

Good luck with getting to the bottom of the issues.

 

Best regards,

-a-

[Guest]

11 hours ago, MB65E said:

Thanks Sir!! 

Thats what I thought. What's the advantages of a chrome faced ring in a standard barrel? 

Are the standard Lycoming rings Chrome? I wasn't aware of the option. 

-Matt

Chrome face on the top compression ring increases wear life.

Clarence

[Sandy]

Thanks for the replies gents. I'll try to answer a few of your questions.

1. I was told by the prop shop that the piston froze in the bore. They told me about the small amount of chromium found. But, source??

Cody - where would cadmium come from?

2. Carusoam -  I have a JPI but don't record from it. There was no metal found in the filter when the shop who pulled the prop checked. Yes, I've been actively flying it - for 22 years. No, unfortunately there was no written warranty but it's an old time shop so I wasn't concerned. A new piston was installed during the overhaul. 

*  Something like that is always someones fault, manufacturer, installer, designer etc. but we'll never know.

3. Matt - I don't know if I have chromium rings or not. I'll call our Lycoming tech rep and ask.

---- I won't spout off here but if anyone is considering a factory engine give me a call.

Sandy

[Guest]

If the propeller piston seized, you need to know if the chromium particles were the cause, you then need to know the source of the particles.  You will then know who to pursue for remedy.

Clarence

[Cody Stallings]

Sandy

The Cadmium comes from the Electra plating process that take place during O/H with your steel parts. Sorta has a Chrome look to it.

When the cylinder is plated, you only want to plate the outside. Where the piston actuates on the inside you want it to remain clean. 

Eletro plating is highly uncontrolled on parts like these, so it is inevitable at some point a small amount will get inside an tighten up the fit of the Piston/cylinder relationship. 

When a Repairman gets parts back from the plater an this issue is apparent, some scotchbright an elbow grease will fix it.

[Cody Stallings]

The Clamps an Counterweights on this particular model Hartzell have fresh Cadmium plating.

 

[carusoam]

Sandy,

Is your shop working with you on finding a resolution?  Or have they asked you to pay full price for this unusual occurrence?

I'm about 98% certain the fine gentlemen above have identified a probable cause of the less than common type failure, a method of resolving it,             ...and possibly a way to get it paid for through a court of law in the U.K.  

They also gave you a way to tell if it was something that should have been cleaned up prior to reinstalling.

I get the feeling you may know this already. The shop has fixed their error, and they want to bill you for the time and materials as if you asked them to do it this way...  or are you still awaiting the fix?

This is probably one of those situations where you sit down together and ask the same question in the opening line.  Eye to eye.

This is your preffered shop, no?

How big is the bill to fix this issue (roughly in AMU would be helpful, or months of hangar rent)

if that was my bird....my preferred shop... and they didn't do the work they should have... I will be in there shop working together on the next project...   we are sort of attached at the hip...

 

Best regards,

-a-

 

...And thanks to the fine gentlemen who continue to educate the Mooney owners here!