I don't have the extensive experience of some of the guys here, so, unless the topic falls within the narrow scope of my knowledge, I stand by and let the "been there, done that" members respond. However, I do visit the various forums regularly and read a lot of posts. Once you join here, reading at other forums is verboten. I thought you knew that. :sidelaugh: :sidelaugh: :sidelaugh: :sidelaugh: :sidelaugh: :sidelaugh: It's a rainy day in SE Texas, so I thought I might jump in here.
As to the 3 quart versus 1 pint issue:
The trans-axle is essentially splash lubed. The turning gears and parts distribute lube to the various components. If I understand correctly, this includes the axle shaft and outboard bearings. Your understanding is correct. However, those outboard bearings are just simple bronze bushings.
The only discussions of potential benefits/problems I have encountered related to the 3 quart versus 1 pint issue are questions about sufficient axle and outboard bearing lubrication.
3 Quart - Argument For
My Ingersoll 6018 Operators Manual recommends changing trans-axle lube every 500 hours. Unless compelling evidence to the contrary is uncovered, 3 quarts every 500 hours doesn't represent a financial hardship, so why not go with the "more is better" approach. Please don't hate me for bringing this to your attention but......you don't read well. :sidelaugh: That 500 hour remark is there for the guys who use their tractors daily and rack up 500 hours or more each year. Take another look at your manual. Owners are supposed to change the trans-axle fluid ANNUALLY or every 500 hours, whichever comes first.
For most of you, it would take ten years to rack up 500 hours at 50 hours of use per year. So if water begins infiltrating the trans-axle after the first two years of ownership, you wouldn't know that for eight more years unless it froze up one winter and you tried to use the tractor. Condensation will take place inside the trans-axle even if the gasket does not leak.
3 Quart - Argument Against
I have seen references to excessive oil weeping at the outboard axle seals. Since oil migrates down the axle to the outboard bearings, is it possible that a high oil level contributes to excessive oil migration and weeping? That's a silly argument by those who say that. There's no pressure on the seals regardless of whether there is one pint or three quarts in the trans-axle. And if they are weeping, it's because they are either worn out due to wheel bushing slop or they have become hard from age and no longer press tightly against the axle shaft.
It amazes me that some owners fail to understand that they own a tractor that is 15 to 40 years old. Nothing lasts forever. No one should be shocked when the axle seals in a 1977 444 start to leak nor should they blame it on having 3 quarts in the trans-axle. If you question my position, then you best be prepared to explain why the axle seals on all the Colts and all the old 100 series Case tractors weren't known for pissing oil all over the ground. After all, in those tractors, the trans-axle was also the hydraulic reservoir and it was filled to within ONE INCH of the top cover with 10 quarts of 20W40 from the factory.
On top of that, the hydraulic oil got heated to a minimum temp of 180F every time the tractor was out working for a few hours. So.......tell me how those seals managed with a full load of hot oil up against them for a full 365 degrees?
1 Pint - Argument For
If 1 pint is sufficient, 3 quarts is overkill. It would be a waste of money and natural resources to use more. And, if the 3 quart fill leads to excessive oil migration and weeping outboard seals, then the lower level might be the cure.
While I agree that oil or any other natural resource should not be wasted, the fact remains that all oil can be recycled. It doesn't wear out. It just become contaminated and therefore unfit for further service until it has been recycled.
Oil is the least expensive item compared to a trans-axle repair. However, if you are not a commercial user, then even if one pint is a bit on the shy side of ideal, it would take a long, long time for any real issue to surface due to a single pint being used.
1 Pint - Argument Against
I pint. Really? Even under the best of circumstances, this seems like too little to consistently provide all wear components with adequate lube. And, under operating conditions, if the lube drops (weeps out or is lost) there isn't much of a safety factor.
Also, if the 1 pint fill doesn't allow lube to migrate down the axles to the outboard bearings, then any condition that lowers the level might subject the axles and bearings to excessive wear.
I am far more in tune with that logic.
Chris reports lots of water and gunk in the trans-axle (a common observation in this situation). In this case, if the trans-axle had a 1 pint fill, the volume of water can easily exceed the volume of oil. How much lubrication and protection do you get from an emulsion of 1 pint oil/4+ pints of water?
Not much but even water is better than no lubricant at all.
Which Lube is Best?
The factory reference materials I have seen recommend 20W40 engine oil or 80-90 EP gear lube. The manuals list the 20W-40 oil first, but do not express a clear preference. I know there are lube purists who may argue the superiority and benefits of one over the other. However, the trans-axles are robustly built and operate at a relatively low speed. As I recall, the drive motors on 200/3000 series tractors only turn about 140 RPM flat out so the trans-axle internals aren't exactly breaking the sound barrier.
Not only are they not breaking the sound barrier but they are not breaking either. In the seven years that I was on the Yahoo forum and the three years on MTF and other forums, I have yet to encounter an owner saying that his trans-axle gears wore out. Any sort of internal breakage of the gears or shafts is ultra-rare to the point of being unheard of. Any breakage is normally attributed to the failure of the four bolts in the carrier shearing or coming off and the amount of lube played no part in that.
However, I do wonder if there are actual benefits favoring one over the other. For example, is gear lube "stickier" than engine oil and thus cling to gears better? If so, is this a benefit? Is there a down side to using gear lube in cold climates that clearly shifts favor to multi-grade engine oil (depending on season/climate)? Oil lubricates best when it is warm. In the dead of winter, the trans-axle oil may take a long time to warm up to an ideal temperature where it flows easily into every crack and crevice. The engine manufacturers have recognized this problem and now specify oil grades that were unheard of twenty or thirty-years ago.
They want super thin oil at cold temps so it will immediately lube the entire engine. Overhead camshafts are of primary concern.
Why did Hydriv recommend 20W-50 SYNTHETIC oil instead of conventional Dino oil? Is it because in synthetic oil, the base stock is the higher viscosity (in this case 50) and modifiers help it pour and perform like lower viscosity oils at lower temps? My reading suggests 20W-50 approximates 90 wt gear lube. Why didn't he fully explain his rationale? Is it because talking about oil makes people crazy? Or, is it because of his well known aversion to conflict? :sidelaugh:
Both, actually. We bar any mention of politics, sex and religion on this site and oil comes in at a close fourth. Synthetic oil isn't oil at all. It's a bunch of chemicals that simulate the lubricating qualities of that crap oil companies extract from the ground. However, using those chemicals means that they can formulate a witch's brew that does not contain the wax found in dino oil that makes it go nearly solid in sub-zero temps.
The use of a synthetic oil anywhere in these tractors is a choice that is left up to the owner. There are known benefits that come with synthetics that dino oil cannot provide. The colder it gets outside, the better the synthetic looks. If it flow easier, then it lubes better at low temps and it also takes less HP to propel the tractor. I suppose that one could argue that this puts less wear and tear on the pump and drive motor but I'd like to know how you could prove that statement to be true.
Oil is often more about opinion than fact. I just read a thread reply on another site where the person stated he used Mobil 1 synthetic in his walk behind tiller and it develops more HP as a result. Hmmmm. What about that statement? On a five hp engine, how much of a HP increase would be realized by switching from dino oil to synthetic? You tell me. And let's say it was a whopping 10%. Could you actually feel that 1/2 HP increase? I don't think so but I'll leave it up to you to draw your own conclusions.
I told you I was bored.
