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-   -   Lycoming SB 632 7/17/2017 (https://vansairforce.net/community/showthread.php?t=151506)

GatorJim 07-19-2017 06:43 AM

Quote:

Originally Posted by tspear (Post 1189005)
And you can thank tort law and lawyers for the lack of transparency.

And for providing Lycoming with sufficient incentive to effect a cure.

F1R 07-19-2017 07:14 AM

Direct this to Lycoming also
 
Quote:

Originally Posted by BillL (Post 1189093)
Rhonda, so what is (your opinion) the design issue? Are the Lyc bushings just dimensionally poor or is the bushing material too soft and they are yielding and losing preload?

Sorry for all the questions, but one more - are the bushings installed with rod and bushing cold and pressed, hot, or light pressed then internally burnished to expand and reamed to final dimension?

The best post yet that can lead us forward, thanks Bill.

Lots of 150 HP 320's (Low CR) are still running at over 3500 hours. Lots of old 540's go well past 2000 hours, so I would deduct that this is either a soft bushing (Material) problem or a dimension (not enough press fit) problem, unless they had a design or process change. However until somebody presents more factual information as to the cause we are all in the dark.

tturner 07-19-2017 08:46 AM

I have a YIO-360-M1B affected by the SB. Here are the results of my research so far. The ST-531 tool is not available in Aviall's system yet nor did they have a price as of this morning. The rep at Lycoming thought is would cost around $200 and he felt there should be plenty available. This tool is new and specially built just for this SB. The connecting rods that use the stretch bolts are not used in most of the engines we have, they are primarily used in the turbo charged and high compression engines ( per Lycoming rep ). Best I can tell they are not used in my engine. This means all I need is a torque wrench for the Connecting rod nuts. The top overhaul gasket kit P/N 05K22949 was not listed in Aviall's system. ( Aviall is Lycoming's largest distributor ) Aviall implied they would contact Lycoming to get it setup. I spoke to two people at Lycoming and no one would venture a guess as to how many defective bushings may be in service. I am going to purchase the ST-531 tool and can pass it on to someone else when I am finished.

jwilbur 07-19-2017 08:51 AM

I spoke with someone at AERO yesterday. The ST-531 will be $216.00 + shipping and can be returned for a refund of $116.00 ($100.00 rental, essentially). However, as noted, it's not widely available. .... Just spoke with another distributor and they are also waiting on the tool.

tim2542 07-20-2017 08:15 AM

Quote:

Originally Posted by RV10inOz (Post 1189077)
Follow up from my earlier post, these bushes are a new design from a year or so ago, and they were a "new design"........wonder why the new design, but now the new one is worse!


I went back through my emails about this and the email was from January 2016, but the issues had been building with many incidents found by just a few shops in Australia on FACTORY engines.

One dated back to 2005 :eek:

This is just the beginning for sure.

CASA and the FAA have been aware of this problem since 2015, and so have Lycoming. I can only wonder if a little aviation outpost like Australia has seen so many why it has not been a bigger fuss in the FAA's backyard.

Maybe Lycoming like to send all their junk engines down under?

So there are TWO seperate bush design problems, the older ones are a problem but the new ones are far worse!

What the heck is going on Lycoming???

David, according to the MSB, the bad batch of bushings shipped between 18 Nov 2015 and 15 Nov 2016
My con rods were reconditioned in June of 2015 BEFORE the bad batch shipped.
Are you saying that previous bushings are defective also?
Also, I'm very interested in knowing what the specific problem is, was it a materials issue or were they dimensionally incorrect?
Tim

659JR 07-20-2017 08:26 AM

bushings
 
The bushings are dimensionally incorrect! I have heard from a large shop that they had issues back on 2015 before the MSB and Lycoming did nothing.

Jesse

tim2542 07-20-2017 10:17 PM

Wow, I would think a competent machinist would check them first and even if he didn't he would notice they press in easier than they should.
I hope they don't expand the SB, so far I'm good by 5 months.
Tim

RV10inOz 07-21-2017 04:02 AM

Tim, there are two problems at play here. The recent bushes from late 2015 were most likely but I can't confirm, to resolve issues that go back to around 2011 and who knows when else.

Strangely the new design that is subject to the MSB were still being shipped to customers down here in Feb this year.

I am guessing this is not the end of it.

HSANTIBANEZ 07-21-2017 07:01 AM

Dear Folks Im very angry, we are building a RV-10 and the engine is in the original crate. It is affected by the SB and lycoming said that they will not change the engine. These is a very bad new and speaks bad of Lycoming responsability.

They said that we have to send the engine at our cost to a service station and open the NEW engine!!

I always speak fine about lycoming engines but these case is inacceptable.

KJBSouth 07-22-2017 07:11 AM

We're at KOSH (drove). Our -M1B is likely on the list based on the time frame of the purchase. Bet the Lyc booth will be crowded. :mad:


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