Perhaps "Lifetime" is Getting to be Realistic

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JHZR2

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Purely anecdotal... 2011 135i, delivered July 2010. Hitting 15k, due for an oil change so I decided to do MTF and differential too... Oil of course comes out dark with a decent fuel odor. MTF fluid comes out clean and clear. no signs of shavings, nothing. Didn't take a good shot of the fluid, but look how it wipes up on the paper towel - clean and clear! The brownish tinge is actually from me wiping my oily gloves on there after doing the oil. The fluid was clear! At least the MT has a drain and fill plug! The Diff only has one (fill) plug, since it is already supposed to be "lifetime" (which I assume has been the case on most all RWD cars over all time - Diffs aren't as commonly serviced as engines and transmissions. I sucked out the fluid and then refilled. The plug had some darkness on it, but the fluid was again clear, no signs of moisture, no odd smells, etc. Another paper towel pic of the diff plug: Ive always read that M cars still get free trans and diff fluid changes at around 1200 miles for free to get any residues or junk out. Maybe M cars do need it, but Id say that manufacturing cleanliness and good syn fluids make an early change out perhaps a thing of the past. I get it, only had 15000 miles, and just under six years. What about at 30k, 60k, 100k. Im sure that lifetime is assumed to be 100k or so for most vendors... And Im sure the fluids would be much darker and more used by then... But Im still surprised how good these fluids looked at this age. Again, purely anecdotal, I know...
 
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I somewhat recently serviced the rear differential on a 2008 528i with 194k miles. This was the differential's first fluid change and my observations were very similar to yours. But the differential's axle seals did start leaking shortly thereafter, but I doubt that it was related.
 
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Our Honda 6MT tends to wear out its fluid (deplete additives?) in about 30k miles and show marked improvements in shift quality afterwords. It's only two quarts and an easy change so i will do it every 30k. VW usually says "lifetime" on MT fluid but i like to change them as well.
 
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Lifetime *manual* transmission fluid, yes. Lifetime *automatic* transmission fluid, NO Manual transmissions don't get as hot as automatics get. Lifetime *manual* transmission fluid is just fine. Most manual transmissions don't require a fluid change, or they might require one at 8000 miles, then never again. This has been the case for at least 20 years. The only manual transmissions that require regular fluid changes that I know of is Honda, but their MTF is essentially motor oil (0w20 since the last 5 years, 10w30 before that).
 
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I've never changed the oil in either diff of the X3 and all appears well after 185k miles. The ATF does get changed at @65k intervals, however.
 
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You would be shocked how good the rear axle lube looks coming out of a truck at 500,000 miles (standard service interval) and that's with 1650-2050 torque (plus trans multiplcation) and 80,000 lb weight.
 

CT8

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Originally Posted By: Gene K
You would be shocked how good the rear axle lube looks coming out of a truck at 500,000 miles (standard service interval) and that's with 1650-2050 torque (plus trans multiplcation) and 80,000 lb weight.
They have filters are are better built that auto type differentials.
 

CT8

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I like doing an early oil change on the drive line components to get out the break in crud.
 
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Originally Posted By: CT8
Originally Posted By: Gene K
You would be shocked how good the rear axle lube looks coming out of a truck at 500,000 miles (standard service interval) and that's with 1650-2050 torque (plus trans multiplcation) and 80,000 lb weight.
They have filters are are better built that auto type differentials.
Many rear axles don't have filters. Some do but it's an option.
 
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Originally Posted By: Gene K
You would be shocked how good the rear axle lube looks coming out of a truck at 500,000 miles (standard service interval) and that's with 1650-2050 torque (plus trans multiplcation) and 80,000 lb weight.
That is true, but you would be surprised how 20k km Mitsubishi Lancer Evo7 (or any) diff fluid looks like. It doesn't look 'as new'.
 
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I like changing my vehicles' various fluids if for no other reasons than doing so is enjoyable for me. Thus the BITOG membership. smile No doubt yours looks remarkably clean! After a ~100k lifetime in the Miata:
 
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With these newish long life fluids you kind of should think that new isnt always best. Does that 135 say anything different for easy service commuting versus riding around a racetrack in mid-July. I still haven't figured out how nowadays 5w-20 is good from -40 to over 100F.....when a few years ago you could choose from 5w-30 up to 20w-50 for similar conditions........and isnt Europe and Oceania still clinging to thick for summer thin for winter? Anyways, maybe the fluids need to break in some to get 'accustomed' to the transmission or differential housing. Also, wouldn't it seem like more harm than good to change Mobil1 EP every thousand miles......it is like the additives need time to activate to do their work. So, what about your BMW trans and diff? It is obviously a low mileage car and maybe this is what upscale auto companies are going to......and briggs and stratton lawn mowers. On rare use equipment and used gently, then it seems permanent fluids have their place. But on work trucks, construction, racetrack, or some other form of severe duty maybe it isnt ideal......but on a 135 which probably will never pull a trailer and is unlikely to be used as a courier for 60-75k miles a year or burning up tires every weekend on the road course...............It may not only be unneccessary to change the fluids ever, but may even be best left alone as the fluid ages gracefully as a fine wine.
 
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when I changed the "lifetime" fluid in my aisin 5spd auto at 50K it did not look to be a lifetime fluid it was more dirty than I cared to see, I didn't get a UOA. But come on what service life are we talking, I think the gravitation to lifetime fill transmission fluid is more they are sick of people changing it and putting the wrong fluid back in or the level being refilled improperly and causing more harm then good to the transmission. I guess they figure 100-150k is better then wrong fluid and failure within 10k just my .02
 
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I’ve always been bothered by the lifetime fluid concept since any fluid can and will last the lifetime of the device where it’s installed (assuming the fluid doesn’t leak out or evaporate). Whether that lifetime is acceptable to the manufacturer or customer, and whether a fluid failure caused the lifetime to be reached are entirely different matters. In the case of vehicles, reaching just beyond the warranty period may be considered a reasonable lifetime by some.
 
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Originally Posted By: Dupree
when I changed the "lifetime" fluid in my aisin 5spd auto at 50K it did not look to be a lifetime fluid it was more dirty than I cared to see, I didn't get a UOA. But come on what service life are we talking, I think the gravitation to lifetime fill transmission fluid is more they are sick of people changing it and putting the wrong fluid back in or the level being refilled improperly and causing more harm then good to the transmission. I guess they figure 100-150k is better then wrong fluid and failure within 10k just my .02
Had a thought, posted in a different thread. I have to wonder if Aisin doesn't see a correlation to clutch material suspended in ATF and transmission life. Looks horrible to us, but perhaps it just doesn't do anything (at least not until some high level of loading). As such, instead of using a paper element in their filter, which requires a pan drop to clean, and which could plug and fail, they would rather the material remain suspended in the oil. If it becomes a problem a simple fluid exchange takes it out, less work. This might be a case where fluid color doesn't mean anything. Cannot tell oxidation from clutch material. After looking around as to how to change ATF on these Aisin transmission it seems very common to have dark fluid on a change; but only transmissions with really dark fluid have owners reporting better shifting with fluid changes. I dunno--I plan to change periodically. Oil is cheap, as they say.
 
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One thing to consider with pretty much any automatic transmission made in the last 15 years is the actuators. Long gone are days of simple, spring loaded check valves. We have electric or electro magnetic actuators that are sensitive to contamination. And once these actuators start operating outside the specified parameters, they will stay that way even with fresh fluids.
 
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I just had my trans transfer case rear different done on my 2012 x5 at 69k miles. Trans oil in the 8 speed was BLACK I am glad I had it done it's definitely not life time. Only one I am not touching next time is the rear but all others will be changed. This is my wife ride with mostly highway driving.
 
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ZF states: Regular maintenance intervals will substantially increase the automatic transmission's service life. ZF recommends a regular oil change at between 80 000 and 120 000 km or after 8 years depending upon the stress. My 2er will be my track car so I'm swapping the fluid and filter at 50k miles.
 
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