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Rotax SB Crankshaft Journal

The new Rotax bulletin affects approximate 3700 engines (that's what I was originally told) verses the original 450 (approximate number).
It stems from the shaft straightening at the factory when these shafts are pressed together. They thought 2 or more bends was the problem, but learned even one bend could be an issue. It is rare and they are just trying to get out in front of this which is better than waiting years and having someone like the NTSB force the issue like they do for the auto MFG's. Rotax tends to be very proactive in handling problems once discovered. If you manage to hit the unfortunate cracked shaft lottery then the engine has to come off and go back to a distributor for a shaft replacement and rebuild. Yes, Rotax will help out.
 
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Close one!!

Hey Roger Lee. Thanks for your input. The strange thing with my 912ULS is that I purchased the engine from Van's in November of 09. My serial number starts with 6775, and it looks like the AD addresses serial numbers that start with 6777. So, I guess I am lucky, so far at least. It missed me by a couple of thousand engines.

Tom
 
Does anybody know where to get the ROTAX CS-PTO Gauge P/N 876260 ? I looked on the websites for Lockwood, CPS, LEAF and Aircraft Spruce, but couldn't find it. I even have an email out to my German cousin to see if he can get me one.

Does anybody know if a fiber optic at the mag plug hole could be used to inspect for a cracked journal?
 
I have tried myself to get a gauge. I was told they weren't in the system yet. So we'll have to wait a few weeks for this to catch up. My own engine is in the affected group. The fiber optic camera won't work. It's too big even with a 9mm lens, it needs to go in at an angle and you need to push against the shaft gear hard enough to try and make it move. The bulletin should be world wide already. It is on their main website.
 
Service Bulletin

I watched the rotax 100 hour check the crank journal video, how does a feeler tell you have a crack or don t have a crack ? Also a question for Jack, what do you mean, Rotax will help out?
 
The feeler gauge will not tell you if you have a crack only if it is completely broken. This lets the more forward part of the shaft to shift a little forward and allows the feeler gauge to go in past the mark.
Rotax knows this is a factory caused defect and will most likely help out with the repair, but I'm not sure exactly how much.
 
Rotax has released an Update to their SB inspecting the Crankshaft Journals.

http://legacy.rotax-owner.com/si_tb_info/serviceb/sb-912-064ul.pdf

The Revision changes the one time inspection into a 100 hour inspection and expands the serial number list of affected engines.

(They'll keep expanding the Affected List until they get all of us!)

Bob Bogash
N737G
It doesn't look all that hard to do the test yourself in the procedure video:

http://rotax-owner.com/index.php?option=com_content&view=article&id=431

This assumes that the tool, which looks to be not much more than a simple feeler gauge, becomes available. I still couldn't find one on Lockwood as of this morning, but it seems as if that would be just a matter of time.
 
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The feeler gauge will not tell you if you have a crack only if it is completely broken. This lets the more forward part of the shaft to shift a little forward and allows the feeler gauge to go in past the mark.
Rotax knows this is a factory caused defect and will most likely help out with the repair, but I'm not sure exactly how much.

We'll, if the crankshaft journal was completely broken, wouldn't that be noticeable without the feeler tool?
 
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Crankshaft Journal

Does anyone know how many engines that have been found with a cracked journal?
 
Hi Morsesc,

If the shaft breaks you may not know it. The way that piece of shaft is held in place it will stay in place. To find only a crack you would have to pull the gearbox. The only way to find a break is pull the gearbox or use the feeler gauge tools find the play or space in the safe.
 
The serial number listed on my engine log book is listed as 5652551. This does not jib with any of the numbers on the service bulletin. What am I missing?
 
No parts to handle the SB

Am I the only one who is irritated about not having the tools to do this service bulletin ? In the face of a possible engine failure? I sure would like a great more detail about the genesis of this SB including other signs of the problem other than oil pressure.

Doug Dahl, RV-9A, RV-12, 66hrs on the 12
 
My German cousin was told it would be two weeks before the tool was available when he put in the order last week.
 
Hi Doug,

Your engine won't fail and you wouldn't know it was even broken. You also may stand a better chance at winning the lottery than having a broken crank. Rotax is just trying to stay out in front of the issue.

I can't get a tool yet either.
 
Vans has posted a Notice stating they have a limited number of the special tools needed for the inspection.

Contact Vans.

Bob Bogash
N737G
 
Vans has posted a Notice stating they have a limited number of the special tools needed for the inspection.

Contact Vans.

Bob Bogash
N737G

Looks like I'm one of the unlucky ones. Talking with Van's parts folks, this should read

...the WILL HAVE (IN A WEEK OR SO) a limited number of the special tools...

I'm a bit too much of a sparky (electrical) engineer and not enough of a metal-bender (mechanical) engineer to understand what is really going on here.. referring to roger's post...how is having a broken crankshaft journal on the power takeoff end of the engine not noticeable? Seems that if broken, I would be getting any spinning shaft going into the gearbox??? Or is that gear that slides around when the shaft is broken what meshes with the gearbox, and hence it still transfers the torque to the gearbox?

Ignorant Engineerofsorts.
 
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Broken shaft

Hi engineerofsorts,

It is where it breaks that's important to note and the support for each side that keeps the parts in place. There is a mark on the new tool feeler gauge and if you can push it it up to or past that mark then the end of the broken shaft is pushing forward in its mount. If it isn't broke the feeler gauge won't go in any farther. It breaks outward of the gear off the crank so that gets held in place by the crankshaft and the bushing holds the other part in place, but there would be a small separation of these two parts that the feeler gauge will detect. If it was only cracked the feeler gauge won't detect it. You have to pull the magnetic oil plug out every oil change anyway so just stick the gauge in to check. It shouldn't take, but a couple of minutes.
 
My German cousin finally got the tool from ROTAX. They shipped it free of charge. I don't have it yet. He's a ROTAX independent maintenance tech and the German equivalent of our LSR-M. More when I have this jewel in my hot little hands!
 
checked ok

In the midst of the condition inspection and our Rotax feeler check gauge arrived last week. Checked it this evening and was ok. We have the new style mag plug and the new torque setting is 216 in lb. the new style is the hex head bolt and not the "torx" style.
 
Just an FYI so people don't panic.
Rotax cut a shaft where they could break and ran that engine for 500 hrs. without any issues. The cut shaft has a wider kerf or space where it could break and it had no issues.
This isn't common knowledge, but I wanted to re-assure some that they aren't going to fall out of the sky.

p.s.
If you have one of the affected engines or you are an authorized and current IRC the tool should be free.
All others will have to pay for the tool because they feel it isn't needed on other engines out of the serial number range.
 
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I was able to rent a gauge from Lockwood and check out mine. It passed! Then returned it to Lockwood. They said they would have them for sale in 3weeks.
Vicky Leroux
n899VL. Flying proudly
 
Someone is sure misinformed. Lockwood needs to have a chat with Rotax or they aren't being straight up. The tools are free to affected engine owners. Rotax told me so themselves. They are also supposed to be free to authorized and current IRC's. CPS in CA said the same thing.
 
The SB has just been expanded to a new, wider range of serial numbers. See here http://legacy.rotax-owner.com/si_tb_info/serviceb/sb-912-064ulr1.pdf
The lowest number is now 6777436. Just higher than my engine of 6777368 so, dodged that one again...
The check remains periodic, every 100 hours or 12 months up to 1000 hours.

Hmmm - actually no change on that lowest number. One of the higher ranges is expanded a bit.

N412BR
 
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Bill, this seems to be death by a thousand cuts. The fact that they keep expanding the S/N list tells me they haven't any idea what ghost they're chasing - bad vendor, bad machining operation, bad heat treat batch, etc etc.

Scary.

Bob Bogash
N737G
 
I'm looking at a used RV12 and it's engine falls under this bulletin. I haven't seen any further posts about this issue since 2013. Has anyone actually found a crank crack and had to have the engine torn down? The plane I'm looking at has had the inspection done yearly with nothing found. Wondering if I need to worry about this or not? Thanks for any input.
Josh
 
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I'm looking at a used RV12 and it's engine falls under this bulletin. I haven't seen any further posts about this issue since 2013. Has anyone actually found a crank crack and had to have the engine torn down? The plane I'm looking at has had the inspection done yearly with nothing found. Wondering if I need to worry about this or not? Thanks for any input.
Josh

Since Rotax bothered to issue the SB it implys that it is possible, but the company airplane that we have that has an engine that was listed, has always passed the test and it has now accumulated enough hrs (1000 if I remember the SB correctly) that the test is no longer required.

I guess the question to ask would be "what is Rotax willing to do to cover the repair if a crack is detected during the 1000 hr period" I don not know the answer.
 
I guess the question to ask would be "what is Rotax willing to do to cover the repair if a crack is detected during the 1000 hr period" I don not know the answer.

Yeah, that's the question.

But the good news is I've only read about a couple of broken/cracked cranks in my web search, so the odds of it happening must be fairly low. Thats why I asked here...since a lot of the earlier RV12's likely had engines covered by this ASB.
Josh
 
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