Bluey Posted January 20, 2012 Share Posted January 20, 2012 Has anyone done the gearbox overhaul on their rotax 912 engines? Apparantly it's due after 600 hours. I'd like to hear about anyone's experience with it. How difficult is it to remove the gearbox? As well as any other problems you might have experienced. Are there any people out there that haven't done it yet and have gone well past 600 hours? I'd like to hear about your experiences too. Bluey. Link to comment Share on other sites More sharing options...
skyfox1 Posted January 20, 2012 Share Posted January 20, 2012 Hi Bluey here is a link to rotax web site you can watch videos of the removal of 912 gear box http://www.rotax-owner.com/ Mine has done 1380 hrs still going strong all l have done are the ADs for my model renewed my carbys new Exhaust . cheers Geoff Link to comment Share on other sites More sharing options...
bones Posted January 20, 2012 Share Posted January 20, 2012 Bluey, what the hell??? never heard of anyone removing the gearbox to rebuild it at 600hrs, mine has done 1600 never touched it, and it cops a flogging, probably full noise 70% Link to comment Share on other sites More sharing options...
PapaFox Posted January 20, 2012 Share Posted January 20, 2012 The maintenance manual spells out that: Gearboxes of series 3 (with overload clutch) and use of leaded fuel more than 30% of operation... every 600hr Avgas is the culprit at play here Link to comment Share on other sites More sharing options...
facthunter Posted January 20, 2012 Share Posted January 20, 2012 It's only the particular gearbox. Lots of the 80Hp motors didn't have it. The clutch has to wear as part of doing its job of damping the vibrations. Its not the gears wearing that is the reason for the adjustment/ replacement. I would stick to the periods specified. You are looking after your engine by having it working properly. Nev Link to comment Share on other sites More sharing options...
Guest davidh10 Posted January 21, 2012 Share Posted January 21, 2012 Mine doesn't have the o/load clutch, and has never been opened. Just did the 1000 hour service last weekend. Link to comment Share on other sites More sharing options...
Bluey Posted January 21, 2012 Author Share Posted January 21, 2012 Sounds like a range of experiences here. I was speaking to airborne regarding another matter and Shane bought the gearbox Inspection up. I called Bert floods up straight after and they confimed that it is a rotax recomended inspection at 600 hrs. I'm wondering if it is really necessary to carry it out as specified by the manual when it is running on premium unleaded petrol. The engine does sound very sweet at the moment. I have spoken to a range of other trike operators in and around YWOL and no one else knew anything about it. Bluey. Link to comment Share on other sites More sharing options...
Guest Crezzi Posted January 21, 2012 Share Posted January 21, 2012 The 912 on Airborne (& most other) trikes I can think of don't have the overload clutch. For these gearboxes, the maintenance manual still specifies that the gearbox is removed & inspected every 600 hours regardless of the fuel used. Cheers John Link to comment Share on other sites More sharing options...
Bluey Posted January 21, 2012 Author Share Posted January 21, 2012 Are there any trikers out there that have had the gearbox inspection done. I've spoken to a few who have basically said to leave it as it will most likely be fine well past its inspection time. Has anyone out there other than David not bothered with it? Apparently if it starts to get loose you could be in for major repairs and you may not have any symptoms until it starts rattling. By that time it could have already done major damage to the drive shaft on your engine for instance. Bluey. Link to comment Share on other sites More sharing options...
facthunter Posted January 21, 2012 Share Posted January 21, 2012 It's pretty simple. If you think Rotax know what they are doing .. Do what they say. The idea that it's going fine and sounds ok is purile after all THEY build the engine and take responsibility for it.. Do you know more about it than they do? Nev Link to comment Share on other sites More sharing options...
Bluey Posted January 21, 2012 Author Share Posted January 21, 2012 No Nev, I'm not at all saying I know more about the 912 than enyone let alone Rotax. I'm just gathering the information I need to make a proper informed decision. Bluey. Link to comment Share on other sites More sharing options...
facthunter Posted January 21, 2012 Share Posted January 21, 2012 Bluey. I'm not directing my comments at you in particular. We accept that Rotax build a competant product, therefore if they suggest that a certain service be done at a specific time, then we can't have it both ways. They either build a good engine and know what they are doing or they don't. Nev Link to comment Share on other sites More sharing options...
old man emu Posted January 21, 2012 Share Posted January 21, 2012 I've spoken to a few who have basically said to leave it as it will most likely be fine well past its inspection time. And are these people qualified LAMEs or L2s with a lifetime's experience in the aviation maintenance business where they learned not only the greasy fingers side of maintenance, but also the legal side? Rotax designed and built the gearbox. Rotax says inspect at 600 hour intervals. Nuff said. Has anyone out there other than David not bothered with it? We have arranged this inspection on a couple of gearboxes in aircraft we maintain. We just whip them off, put them in a cardboard box and mail them to Bert Flood. Costs us less than $20 in postage. We haven't had any other expense other than the cost of inspection Apparently if it starts to get loose you could be in for major repairs and you may not have any symptoms until it starts rattling. By that time it could have already done major damage to the drive shaft on your engine for instance.Bluey. That's why you pull the thing off at the recommended intervals and send it to a qualified service centre. Have you ever heard of "A stitch in time saves nine'? You said, "I'm wondering if it is really necessary to carry it out as specified by the manual when it is running on premium unleaded petrol.". This indicates that you haven't thought about how your engine/gearbox works. The engine burns petrol, be it mogas or avgas. None of this petrol should get near the lubrication system of your engine. The lubrication system is oil. The gearbox does not share the engine oil, so how could the type of petrol have any effect on the lubrication system of the gearbox? You also said, "I have spoken to a range of other trike operators in and around YWOL and no one else knew anything about it. " It is the owner's responsibility to know the maintenance requirements of the aircraft (but not necessarily how to carry out that maintenance) as well as to know what compulsory maintenance actions are required for the aircraft. If these other operators don't know the maintenance requirements for their equipment, then I would take anything they said about maintenance with a very small grain of salt. So now you know. The gearbox comes off every 600 hours for inspection by a qualified service centre. End of story Old Man Emu 1 Link to comment Share on other sites More sharing options...
Dieselten Posted January 23, 2012 Share Posted January 23, 2012 My understanding is the gearbox does share the engine-oil, which is why a friction-modified oil MUST NOT be used. Aeroshell Sport Plus 4 is developed by Shell in conjunction with Rotax specifically for this engine family because of this requirement. It follows that combustion residues will be distributed into the gearbox. If Rotax specify a 600-hour inspection (note the word is inspection, not overhaul), then unbutton it at 600 hours and send it away for inspection. When it arrives back, bolt it back on and re-set the "gearbox-clock". Link to comment Share on other sites More sharing options...
old man emu Posted January 23, 2012 Share Posted January 23, 2012 My understanding is the gearbox does share the engine-oil, I was corrected at work today. You are right, the gearbox does share engine oil, and if the fuel used contains lead, the lead does get deposited aroung the oil system, including in the gearbox. The 600 hour INSPECTION is a chance to flush the lead from the gearbox. The 600 hour inspection also provides the opportunity to check wear and clearances so that your gearbox is returned to you in a "near new" condition. OME Link to comment Share on other sites More sharing options...
fly_tornado Posted January 23, 2012 Share Posted January 23, 2012 I thought they re-shimmed the bearings? Link to comment Share on other sites More sharing options...
old man emu Posted January 23, 2012 Share Posted January 23, 2012 Dunno what they do during a 600 hourly. I just know that the gearbox comes back and is OK for another 600 hours use. That's a lot of years for the average pilot. OME Link to comment Share on other sites More sharing options...
old man emu Posted January 30, 2012 Share Posted January 30, 2012 That gearbox arrived back from Bert Flood today. 600 hour inspection cost $535 including return postage. If I get a chance I'll copy the invoice and you can see what was done. That means that gearbox maintenance would cost you just on $1 per hour (including an allowance for inflation). OME Link to comment Share on other sites More sharing options...
old man emu Posted January 31, 2012 Share Posted January 31, 2012 Here are copies of the paperwork we got from Bert Flood OME Link to comment Share on other sites More sharing options...
Kev Posted February 18, 2012 Share Posted February 18, 2012 Plus, of course, if you comply with the Rotax maintenance requirements, you will remain LEGAL (and insured). Safe Flying kev Link to comment Share on other sites More sharing options...
Bluey Posted February 18, 2012 Author Share Posted February 18, 2012 That would only apply if an incident could be shown to be directly caused by a gearbox failure. Bluey. Link to comment Share on other sites More sharing options...
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