mechanic80 Posted August 7, 2010 Share Posted August 7, 2010 A number of RGB's have failed due to quite a handsome size of metal chunks detected by magnetic drain plugs..what could be the possible reasons for this cause... oil used is 23699 and is changed properly. Propeller dynamic balancing is also done properly. engine used is T-56-A-15 unable to find a good reason for these overhauled RGB's.:confused: Quote Link to comment Share on other sites More sharing options...
mechanic80 Posted August 7, 2010 Author Share Posted August 7, 2010 hey big guys give an input...need help Quote Link to comment Share on other sites More sharing options...
tusker Posted August 8, 2010 Share Posted August 8, 2010 Yes!!......all I can say is that it was a concern in the years 70-80. I forgot why!!.....Shame on me!!!.......................John Boy Quote Link to comment Share on other sites More sharing options...
Herc 308 Posted August 8, 2010 Share Posted August 8, 2010 I heard yrs ago the they were having problems with the -7 and -15 engine, it had to do with the engine only having I think 2 support bearing in the engine and it was causing vibrations into the gear box and causing problems. I was also told in 2003 by a Rolls Royce field unit in England doing work on the Brits J models that that were having the same problems with the RGB on the J model that they had yrs before with the -7 and -15. The fix was they had to put a extra support bearing some were in the engine to get rid of the vibration and it fix the RGB problem. This is what I was told so it is what I can only go by. One other thing to look at is hook up the vibration kit to the engine and check things out and check the read out for a freq that not suppose to be their. Hope this helps you out. Herc 308 Darrell Quote Link to comment Share on other sites More sharing options...
mechanic80 Posted August 8, 2010 Author Share Posted August 8, 2010 well the vibrations are fine... any other clue Quote Link to comment Share on other sites More sharing options...
Lkuest Posted August 8, 2010 Share Posted August 8, 2010 Where are you checking the vibrations? There are several methods of doing a vibration check. There is the single Velo on the RGB, a single accelerometer on the turbine, the torquemeter runout (finding a lot of these bad), and a multipoint harness (never done one, but the Tech Data exists). The RGB Velo doesn't always catch everything. The only other thing I can think of is check your supplier of RGB's. If it is Rolls Royce, I have no idea. If you are getting refurb units from third-party companies, you might want to check into their credentials. They may not have purchased the proper tech data for RGB overhaul, or are using unapproved materials or parts during the rebuild. Even through legit channels, we managed to recieve a large batch of engines with bad Prop Brakes causing many engine removals, even on a brand new motor. It happens. Quote Link to comment Share on other sites More sharing options...
NATOPS1 Posted August 9, 2010 Share Posted August 9, 2010 What are your oil pressure limitations? 130-250 or 150-250? Quote Link to comment Share on other sites More sharing options...
mechanic80 Posted August 23, 2010 Author Share Posted August 23, 2010 well the RGB oil pressure is 150 - 250 psi Quote Link to comment Share on other sites More sharing options...
NATOPS1 Posted August 24, 2010 Share Posted August 24, 2010 "mechanic80 well the RGB oil pressure is 150 - 250 psi" Well, it depends on the oil pump installed. Some operators still use the 130 to 250 limit. Problem is 130 is good for the old pump but 20 PSI low for the new pump. Hence my question..... The new pump should be installed on most engines. A paper was published about the issue in 99 i think... Basically at 130 there is not enough of a "film" covering the RGB parts and failures result. This paper also addresses the oil pressure flux limit and range. Quote Link to comment Share on other sites More sharing options...
tusker Posted September 2, 2010 Share Posted September 2, 2010 .............you ain't god!!!.......The RGB manufacturer has to give you some feed back!!!!..............John Boy Quote Link to comment Share on other sites More sharing options...
Mcmuffin07 Posted April 12, 2011 Share Posted April 12, 2011 check to see if your torquemeter is the midbearing type, and if not that could be your cause. did you do an engine signature run and send data to Kirtland yet? also might suggest a torquemeter runout, per the 71jg-00-3. otherwise i got nothing haha. Quote Link to comment Share on other sites More sharing options...
DanGothe Posted May 4, 2011 Share Posted May 4, 2011 I know we have had some come through here and we have only a couple of Hundred hours on them and they fail and we do DR'S and Depot really has no answer for them. I just feel they (depot) are using refurb parts that have been refurbed one to many times. I know here at my base we can't get into the front half just the rear case but most failures seem to be in the front section. I know we are just getting into the 135 day torque meter runs and feel once the info gets processed we will be changing more RGB'S I know years ago on the early -7's we ran the Torque meter Run out tests as we had no mid bearing that caused us problems.An engine Mechs work is never done. Quote Link to comment Share on other sites More sharing options...
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