Gearbox Oil Additive

[Waddles]

Thanks again Guys,I finished my current training block this morning having noted that the GB temps were getting right up there. Had a cuppa whist everything cooled and pulled the box.The split was relatively easy, then the troubles started. I really would like to be the supplier of locktite to Neil!Upper 3/4 of the internal housing badly stained with "burnt" oil. Lower 1/4 where the reservoir is relatively clean. It smelled of overheat as well. Unable to disassemble one shaft and associated attachments due to the need for a special tool it seems. I"ll try with C spanners tomorrow, otherwise I"ll have a tool made.Managed to get 2 bearings out. BOTH STUFFED. Expect the other 2 to be the same. The stuffed bearings are those on the upper shaft in my insallation which is the one connected to the doughnut. This is lubricated with splashed oil thrown up from the lower cogs. None of the bearings had inner oil seals, so the bearings were all being lubricated. Seems a different setup to that which Sam had troubles with.I"ll take some photos tomorrow and post them if I am able.Now my musings return to the original subject of the thread and I wonder why ATF fluid is used instead of gear oil? The only answer I can find is that ATF can accommodate higher temps than regular gear oil. Mmmmmmm. do i go back to ATF or persist with my gear oil and additive. Ohhhh. Decisions, decisions ..... and I thought that when I retired, all that would disappear. Fool!!What I"ve learned so far: If you operate an Autoflight gearbox, fit an oil temp system and watch it like a hawk.Regards,Waddles

[nunto]

I only run strait moreys in gear box never had a problem.

[Tsemler]

Outta interest what hours does Neil recommend changing the bearings at, I heard on the grape vine that they should be changed well and truely by 300 hours anyways ????Like I said in my first post go to a 80-90w oil and 1/4 of the autoflight gearbox"s capacity of moreys oil stabilizer, it"s been done with a few autoflight gearbox"s down this way and it WORKS!!!!

[muzzza]

Hi TonyTry this one nckm@wave.co.nzRegards

[Disco]

Autoflight issued an "ADVISORY" on 17/4/2012 about this problem.Apparently it is only a problem on the 2.5 motors.

[Waddles]

Gidday Guys,For starters, how did you guys become aware of the advisory bulletins please? Email or the autoflight website?Pix of my box attached. You can see the colour difference between the lower 1/4 and the rest. Can"t get the retainer nut off the other shaft yet. Busted a C spanner and tried heat. My techo reckons locktite 609 has been used liberally. He"s going to make a tool for the job.Trouble sourcing bearings locally especially name brand and I"m not going to use anything from a source that we don"t know. Eventually found a place with the bearing coming out of Melbourne.The bearing that I had trouble locating is a 6011 2 RS C/3. The one that came out only had one seal on the outside, so I"m guessing that this is the one that Sam removed when he had the problems. We"ll remove both on both big bearings anyway. The separate seal fitted should do the job and if it leaks, it will stop the housing from rusting anyway!!!!So thumb twidling for a couple of days now.Waddles.Tony. The email for Neil that Muz posted is the one I have.

[bones]

Allan,My 2 cents worth if you like, i would be using a 80-90 weight gear oil(or even heavier) also as Dean said, the reason is from, my trade back ground, is the heavier the work the heavier the oil you need to use, otherwise the oil foams up from being "squashed" out from in between the working surfaces, once it foams it not work jacksh*t, hence the burned oil stains on the top of the box, that is from the foaming effect, the oil is VERY hot and full of air, so it "stands up" and hence the reason for the stains way up on the top of the box.Oil can be damn hot without burning as long as it has not foamed the rotax motors are an example of this the max oil temp is 135*C, you can run the oil that temp without damage because they know they have the right weight oil not to foam.Once you get the right oil then yes you could then put additives in to help it lubricate, most of the additives i feel are there to help the oil stop "foaming", it is this foaming that leads to damage, oil with air in it is no good lubricating because air does nothing.Gear boxes on conveyors ect at work for eg. run 220 ep(extreme pressure) gear oil, these things are pulling tons of rock, i would definately be going heavier not lighter on the oil IMHO.

[Brian]

I agree 100% with you Bones. Same reason not to overfill engine oil cause the crank picks up the oil and foams it then the oil temp goes through the roof and goes black .ATF fluid is great under pressure in a torque converter like my old loader but gearboxes just got to have a heavy oil & while I havent tried it, I have some 140 gear oil recommended for Mack truck diffs. Now a Mack putting out 500 plus Horses with 3 trailers on a day of 40C would likely be under a bit of pressure and yet diffs last millions of K"s.Allan, not sure if that nut you are having trouble with is the same as a Rotx but Rosco used a spanner he built, has a handle about 4 foot long & he uses plenty of heat as well to get that nut off. He used lots of locktight too.I"m still at a loss why your gearbox should be getting so hot

[Waddles]

The problems started whilst I was using the syntrax as recommended and I hear what you say about the heavy weight oil.I don"t think foaming was the cause of the heat. The 6011 bearing on the input shaft was rough when I finally got the box apart. So my guess is that the bearing started to fail which caused the abnormal temp rise. The smaller bearing is a roller bearing and the rollers were scored, all in the same place. Again I reckon from the bits and pieces that came from the 6011. I could probably get a photo of one of these but the res I would need to use wouldn"t upload to the forum. Also flecks of metal left on the internal casing when the oil was drained.So either the 6011 bearing is not up to it, or it is not getting sufficuent lubrication to reduce friction and therefore temp resulting in early failure.I"ll go and have a play with the camera.Waddles.Just had another look at the outer housing and there is a hole drilled such that oil should be "flung" onto the outside of the 6011 bearing on the input shaft. However, with the integrated oil seal on the outside of the bearing, I can"t see how the oil can get into the rollers from that side, or even flow through. So I"ll definitely be taking both seals out of the new bearing when it comes.

[Waddles]

Here is a pic of

[tonydenton]

thanks muzza i"ll give it

[GraemeMonro]

Waddler,
..........

[Waddles]

Thanks Tony and Graeme,By the way "G", thanks for the other nite!I"ve emailed Neil asking for some answers and info. I await. If this rebuild doesn"t work and I don"t think 500 hours is unreasonable, then there is an alternative that is cheaper and allegedly better in service. TBC.I specified when I ordered the bearing, that it had to be a known brand otherwise it would not be accepted. I also said that there were more orders if this one proved good to their word. We"ll see.Waiting for the dismantling tool to be made for more movement forward.Any opinion on the hole in the housing please? It"s got me really intrigued as to how the oil can get to where it looks like it"s supposed to be when the external seal appears to block the majority of the flow.Hey Darren. R U about?Waddles

[yoshi]

Hi AllWaddles - Yes am still here at times, if you need anything please just ask and ill do my best to help out if I can. I missed your post re the oil analysis, there are several labs you could use and they all do pretty much the same thing, I can email you the info of the company I use to work for if you like, they have labs in most states and have a good reputation in the industry. Tony - Not sure as to why yould would think I would be having a chuckle at your misfortune or anyone elses for that matter, its certainly not what I am about.All - Just some info in regard to the various oil viscosities that are being mentioned, there are two major bodies that govern the oil viscosities that we see in everyday life, please dont get too caught up in the numbers that you see without understanding the testing and classification system they are being rated under.Automotive oils are classified under the SAE system (Society of Automotive Engineers)Industrial oils are classfied under the ISO (International Standards Orginisation)To give you an example of how the viscosity grades can become a little confusing the following is a rough guide as to what you may see, SAE 90 Automotive gear oil has a viscosity of appoximately 200 cSt at 40cSAE 50 Automotive engine oil has a viscosity of approximately 200 cSt at 40cISO 220 Industrial gear oil has a viscosity of approximately 220 cSt at 40cThese values are just a guide and vary or course between manufacturers but all values will fall between a range as determined by the governing bodies, so you can see how we have three different numbers yet the weight of all three oils is virtually the same at 40c, I hope this makes sense.RegardsDarren

[Waddles]

Thanks Darren and All,Tony. That is the correct email address for Neil.I spoke with Neil this morning and here"s what I"ve found out:He was surprised that the 6011 bearing was the one that was failing. It is usually the smaller one on the input shaft which is the one that Kevin T checks by removing the small access plate and checking for abnormal movement. No suggestions from Neil as to why mine failed as it did. However, he did mention that temp monitoring and oil inspection at changes need to be ****. Castrol Syntrax Manual is apparently a Manual gearbox oil. Not ATF as I thought. Not sure why I formed this opinion. Could be that there is also Castrol Syntrax ATF which is likely on the same shelf in the store as the manual stuff. Neil says to use it, changing at 25 hour intervals. He doesn"t object to the use of additives but cautions against those that may cause deposits to build up on the working parts.The boxes that Russ and I have are early models and were produced specifically for the EJ22. When they started being used in the EJ25s, all seemed to be well for a while so he let it lie. Now, he suspects that this is not the ideal application for our boxes. I"d agree. His H6 model would be better suited. Later boxes are capable of an upgrade that uses a larger diam output shaft with a wider gear on it. Ours cannot be modded easily and he couldn"t estimate a cost for the mod. His best suggestion was to sell these older boxes for EJ 20, 22 and smaller applications and upgrade to the H6 box. Much stronger and no failure history. Costs about $300 more and is slightly heavier.The hole in the housing that I thought was for lubrication is actually the opposite. It relieves any pressure buildup between the outer oil seal and the seal in the bearing which will allow small quantities of oil to weep past it. He also recommends Viton seals and bearings from a reliable supplier. Definitely not the internet.So that"s it in a nutshell. Seems like the H6 is the only gearbox that is suitable for the EJ25 application.I"m getting a tool made to remove the retaining nut, so it will be available to borrow if anyone needs it down the track.Waddles.A special tool is required to facilitate the removal of a retaining nut on the output shaft allowing access to the gear. This is on a tapered shaft and a puller and perhaps slight heat will be required for removal. High strength locktite (609?) is used liberally throughout and this means that extension bars on spanners or socket handles will be needed to remove a couple of bolts. The one I used was about 1200mm long and still needed muscle.