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SB for Crank shaft Journal inspection


Rich

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Ouch!

 

Mine (manufactured 2007- #5648194) seems not to be in the range.

 

The actual check seems pretty easy - with the tool mentioned another few minutes when you pull the magnetic plug at scheduled oil changes.

 

Not so pretty if the little gauge slides in too far though! :(

 

(note: you can select the text and make it any size you want, even after posting.)

 

(note2: for some reason I found the presenter in the video unintentionally hilarious at times! :D )

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Jim Mead,

 

My prediction comes true. I think I made this prediction about the middle of Sept. Sounds like insider trading to me. :)

 

 

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FYI,

 

This affects mostly engines in 2009 - 2010 year time period. No sure of the exact dates. About 3700 (not exact number). The original SB was for about 450 engines. It needed to have the gearbox pulled. Now you can do the check with a simple tool.

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Roger,

 

Worse case scenario. If the journal was cracked, what is the approx cost for the fix? Does Rotax offer any monatary reimbursement for a low time engine (100-200 hrs)?

 

I plan on ordering the tool and checking at every oil change. Do I need an A&P to sign it off?

 

Rich

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Hi Rich,

 

If the shaft is cracked the engine has to come off and go to a distributor to have the case split and rebuilt with a new crank shaft. Rotax will help on parts and possibly labor, but at this time I do not know how much. I can find out so I'll get back to you.

 

The cracks formed on a couple of engines. This was done at the factory when the factory pressed the crank shaft sections together. The power side was not always straight and many years ago they threw away a number of shaft parts. Then they started to bend the shafts, 1-2 times to straighten them. The first SB out thought it might only be shafts bent twice, but they found out it could happen with only one bend so they expanded the SB to include all those engines too. They figure if the shaft is good up to 800-1000 hrs. it probably will be okay, but it should be checked and logged each annual or if you have a sudden drop in oil pressure.

This hasn't been a major wide spread issue, but one they definitely want to keep a close eye on.

 

I think that new guy on the video may be just starting his acting career. :D

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Hi Rich,

This is rare, but happened to a couple of people. I do not have an exact number. Rotax is very good about putting notices out right away to be on the look out or parts replacement before it becomes an epidemic. Fore warned is fore armed.

If you want to do it every oil change you could log it. More won't hurt, but it should be documented at the annual or 100 hr. by the mechanic.

 

Hi Jim,

 

The answer is yes it will run and fly. This would be a good time to pay attention to an unusual and sudden oil pressure drop, new engine vibrations and any metal on the mag plug. The tool won't tell you if you have a crack only if it is completely broken.

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That had me concerned. My plane is a 2010, but the engine was manufactured in 2009 and the serial number is not included. The test is not that big a deal, but a problem with the crank would be. I hope it is simply a matter of using the gauge for you Rich.

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This also applies to my engine. Looks like I'll be ordering the tool and finding a local A&P to do the test. Right now I think I'm going to test it right away and then as perscribed (of course it depends on how long it takes to get the tool). I have 180 hours on the engine.

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Dan, and others needing the Rotax tool # 876-260 to check the crankshaft journal.

 

If you call Lockwood at 1-863-655-6229 (press 3 for maintenance) Dean will put you on an E-mail list and you'll be notified when they receive the tools from Rotax.

 

Call times are from 9-10AM and 2-3PM eastern time.

 

Rich

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Dan, and others needing the Rotax tool # 876-260 to check the crankshaft journal.

 

If you call Lockwood at 1-863-655-6229 (press 3 for maintenance) Dean will put you on an E-mail list and you'll be notified when they receive the tools from Rotax.

 

Call times are from 9-10AM and 2-3PM eastern time.

 

Rich

 

Thanks Rich. I just got off the phone with Dean and am on the email list. One of the things he told me was that a flight school had an engine from the earlier SB group that flew approximately 3 months with the crankshaft broken. When the plane was brought in for an 100 inspection the mechanic pulled off the gearbox and he end of the crankshaft came with it. The flight school operator did mention that there were some unusual vibrations.

 

I still can't get my head around how a broken crankshaft can still drive the prop, but Dean (as Roger said earlier) that it will continue to operate. He did say to pay particular attention to your oil pressure.

 

EDIT: I went back and looked at the SB again and on pg 10 the last illustration shows where the break happens. Now I understand.

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I still can't get my head around how a broken crankshaft can still drive the prop, but Dean (as Roger said earlier) that it will continue to operate. He did say to pay particular attention to your oil pressure.

 

If it breaks longitudinally, I can see the two halves keeping each other in place and still turning if they are held tightly enough in the gearbox bearings.

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According to the SB, it shears outbound (toward the front of the engine) of the gear, so it is between the front of the gearbox case and the gear on the crankshaft (basically at the front end of the crankshaft).

 

I asked Dean if there was any in between failure and he said because that nut it torqued to 148 ft-lbs, it is not going to crack, but either hold or break (shear).

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Cracked / Broken crankshafts...That is right up my alley.

 

You can not check cracks in crankshaft with your naked eyes, unless you have a magnetic particle fluid & light.

Cracks which can cause crankshaft to break can be in microns...You can definitely see broken though...I would assume this notice is to change all crankshafts between the serial numbers.

 

If you would like to know...

 

There are several reasons why crankshaft breaks during the operation.

1. Bearings are not floating on main journals & pin journals as freely due to oil hole blockage

2. Journals are not machined properly

3. Crankshaft was not forged properly and folded material, inclusions

4. Induction hardening or fillet roll of main & pin journals did not hardened the material correctly

5. Crankshaft was not balanced within the specified tolerance

6. Too much torque can also break crankshaft (depends on material & specs)

 

Only way to ensure your safety, change cranksahft, don't just check with your naked eyes and thinking it's ok.

 

taka

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One more info.

912 crankshaft has 4 pin & 3 main journals. Pins are where connecting rods connects & mains sits right on crank casing. This service bulletin says front, so post end without the fly wheel is mounted on. Weired part is that cranks are breaking from the #1 main. Usually crank break from pin journal thrust wall since those areas deals with more stress from combustions...

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In South Africa 21 October 2013 one of the affected engines came to an abrupt stop at 300 hours with a broken crank, so don’t think that your engine is going to take you to the next 100 hour inspection. The Rotax distributor is offering………….. No, not a new engine. A new crank shaft and that is it !!!! If the recall of each of these engines were to cost BRP Powertrain $ 5,000, that would cost the company $18,500,000. Will they be able to take the punch? This might explain the absurd 100 hour inspection regime for a manufacturing defect that could result in sudden engine stoppage at any time and without warning. Potentially this could break the company if not your neck.

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Hi Cranky,

 

If the engine came to a stop then it is the first I have heard of. I don't see how it would stop the engine. The break happens after the gear so that stays on the crank and the last little piece is in the bushing with no space or any where to go. The couple of engines that have broke ran just fine until checked. This problem should be a rare event, but Rotax is trying to stay out in front of the problem. Most of these affected engines won't ever have an issue, but like anything else you could be the unlucky one. They are not going to replace all the engine cranks, only ones that break. I see the one in Africa broke around 300 hrs. Rotax figures if it makes 800-1000 hrs it probably will never break. I haven't heard of any in the US with a problem, that said if it has already happened it hasn't gone public.

 

All this is a wait and see for all of us affected. No on knows for sure how all this will play out, but my personal guess from a little inside knowledge is it won't be that bad as a whole. If you're the one it happens to then it won't be good.

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