Lycoming has issued Mandatory Service Bulletin 632 that requires owners to check their engines for connecting rods that contain bushings that do not meet Lycoming Engine’s specifications within the next 10 hours of operation.
The bushings were manufactured between November 2015 to February 2017.
The Service Bulletin opens with a warning to owners: “You must complete the Required Action in this Service Bulletin. If you do not…and the connecting rod bushing moves out of place, the connecting rod can fail and cause un-commanded structural engine failure.”
The Service Bulletin contains a list of engine serial numbers that may be affected. It then explains what needs to be done to correct the situation.
The company estimates the work to correct the problem could take 12 hours for a four-cylinder engine and up to 20 hours for an eight-cylinder engine.
Just got my letter from Cessna, it says:
——————————————-
WARRANTY
…
There is no labor allowance available for the engines that have ordered and installed the LW-03923 Connecting Rod Bushing.
…
Credit After this service document has been accomplished, a claim must be submitted to Textron
…
Expiration: July 26, 2018 (after this date the owner/operator assumes the responsibility)
———————————–
Well, my flying sardine can isn’t affected. Good luck to those of you who are.
It isn’t an AD so it is not mandatory for 91 operations — unless I misread the regs.
We got lucky, all three club planes have lycoming engines and none of our serial numbers are on the engine list on the advisory. I feel very bad for anyone who has to go through this though… 12 hours? No way. Get yer wallets out (again).
WOW! I just read service bulletin # 632 this is all bad no matter how you slice it. Either you dismantle your engine half way including the cylinders, or if you need to replace the connecting rod bushing, (wrist pin bushing) you will need to split the cases, a major ordeal. What a great big giant bummer to say the least. Damn! I remember installing new rod bushings in connecting rods after you install the new bushings you need to machine the new bushings to fit the wrist pin, and have to hold total float from one end of the bushing to the other no more than .0006″ of one thousand of an inch. This is going to be very expensive folks.
Are these the wrist pin bushings??? If so, how is this going to cause connecting rod failure? If these bushings do come loose they usually work their way outward and score the cylinder walls, This is only if it is the wrist pin bushings. Clearedy is needed here, thanks
This is going to be expensive. Correct me if I’m wrong, but it seems to me anything involving connecting rods means removing the engine and splitting the case to get to them. 12 hours? LOL! I think this should be paid for by Lycoming, but probably wont.
No case split required. Baffles, exhaust, intake and cylinders do need to be removed though.
Simple question – who’s paying for this work – Lycoming?
If your engine is from Lycoming they will pay the 12 hours. If not we’re left hanging out, and I for one am very upset. The club plane is booked out for all summer, and the tool to check if the busing will move is not available. So here we sit, looking at a plane with a brand new field built engine that we can’t fly, and no support from the factory.