Lifetime ATF / Differential Fluids

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Jul 17, 2003
New York
In my BMW manual, it says my ATF & Differential fluid is Lifetime Fluid. Now if BMW was going to guarantee me that is for *my lifetime*, this question wouldn't even be posted . With that said and I have the standard 4 yr, 50K warranty.........whats your take on the Lifetime fluid or me doing preventive maintenance. My 2003 X5 is about to hit 23K-2 year mark. I would have done the above at the 30K mark with the ATF/diff fluid changes. I'll be bringing in the car to my local tuning shop to get a summer tar replaced and coolant changed. A bmw technician told me he didn't recommend changing the lifetime fill fluid because, "the fluid has additives and detergents that cause increased wear during the early life of the fluid. Changing the fluid will cause accelerated wear that the mechanical components were not designed nor built to handle." I believe the OEM ATF fluid is Texaco ETL 8072B. The ATF fluid is around $100 for 5L --- BMW branded
heh....I was planning to go with the Specialty Forumlations myself when the 30K mark was coming up ! However, I have spoken to my service advisor at times and been told that when they have done ATF fluid swaps on the same vehicle with 75K miles on them, the fluid is still looking brand spanking new. There is a drain plug & fill plug on the side of the tranny but no dip stick. However, I'm not sure if the OEM BMW ATF has specific frictional characteristics that is speced vs. if I went the Specialty Formulations route. BMW used to recommend the following - Radiator flush every 2 years. Manual tranny oil every 30k Differential oil every 30k AT tranny oil and filter every 15k While synthetics may have changed certain things like oil, and now the *free maintence* it looks more like this Radiator flush every 4 years. Manual tranny oil every 100k (BMW’s definiton of “lifetime” fluid) Differential oil every 100k AT tranny oil and filter every 100k
For certain it is market driven. Most folks will surely welcome the BMW 4yr/50,000 mile- maintenance included warranty also. But it is not the full story. The "scheduled maintenance included" is also included in the price. So in effect you might be charge FULL price UPFRONT for scheduled maintenance that is performed 1 to 4 years, or some miles, later. So a normal customer to BMW DEALER transaction would be paying the BMW independent dealer (at the time of the service) say 150 dollars for a scheduled oil change. Under the "scheduled maintenance included menu" now becomes a warranty issue and the dealer now submits a warranty performed action (to BMW, or whomever handles this for them) and is reimbursed at a much lower rate by BMW and parts at wholesale or below (say $55). Even unscheduled or warranty work components are built into the price of the vehicle (so are all others but...) This of course is seamless to the customer. Of course the reason why this works is because of BMW dealers usually charging far above most other dealers or independents for each line item of maintenance. So it might seem refreshing to a BMW customer to walk out the door with a free latte and just a sheet of paper detailing the service and "no charges". There are a lot of reasons why BMW is one of the more profitable mass marketed car companies. So germane to the life long synthetic fluids: ATF and differential, it is unlike engine oil in that combustion contaminates are not part of the reason why you are changing the oil. In fact the only real enemies are normal gear wear and heat generated due to normal operation. So to me the real question is what you are really buying? If it were me, I'd define what lifetime is. So if you plan to keep the vehicle 200,000, 300,000 miles, by all means change every 100,000, as a periodic baseline type action. If you tend or plan to keep it like normal folks (8.5 years, 12-15k per year, why bother? Take the money you would save by not changing and take a good long road trip. [ February 27, 2005, 02:01 PM: Message edited by: ruking77 ]
Originally posted by chefwong: However, I have spoken to my service advisor at times and been told that when they have done ATF fluid swaps on the same vehicle with 75K miles on them, the fluid is still looking brand spanking new.
Look brand new? How many UOAs did he show you? None? I thought that would be the case. So please ask them how they know it is like new? There are very expensive machines that analyze these fluids & if he can tell by looking at it, he can make a lot more money doing lab work. He would save labs millions of dollars a year. This would be my very serious and sincere response to someone like your service advisor.
I have for a long time thought it oxymoronic that service places have not offered or used as part of their service offerings, oil analysis. So as a matter of course to expect a service advisor to recommend testing or oil analysis might be expecting far too much. It isn't as if they do not know about it since they probably use an oil analysis to deny warranty should the situation present itself. [Frown] [Smile] So in a more perfect world, one would do an oil analysis of the ATF and Diff and change only when needed. My guess is less than 1% of folks who follow this procedure.
This is one of the reasons I decided to "lease" the BMW and not worry about it. I am no going to be left holding the keys when the warranty and service agreement runs out. What happens to it after My wife and I are done with it is none of my concern. The other vehicles are keepers and are treated much different.
I personally believe that the advertised "fill for life" fluids in any car/truck/gizmo should read "fill for the life of the loan." The auto manufacturers are hoping to keep you continuously buying new cars/trucks/gizmos and will recommend service intervals on just about everything to keep it that way. Me - I change the fluids regularly, buy cars/trucks/gizmos on a 10 year cycle. And give the old ones to my family - they're not worn out - I'm just tired of them - the real reason to buy a new one!
Hi, I have operated heavy trucks (500hp - GVM42.5t)for 1m kms (620k miles)over five years without lubricant change with the following results; 1 - Synthetic SAE50 (Castrol/Mobil) - UOAs still within Eaton Fuller contiuned use specifications (we estimate in excess of 130 000 gearshift) 2 - Synthetic 75w-90 GL5 (Castrol/Mobil)- UOAs still indicate suitability for further use according to Manufacturer's specifications We have suffered no abnormal seal or wear issues in this time. The gearboxes still have "new" gearshifting feel Oil temperatures during this time have averaged: Gearbox - 86C Differentials - 90C(front diff) 94C(rear diff) Regards Doug
I'm not a fan of 'lifetime fills' either, but there don't seem to be lots of failing diffs in cars. Trucks can have more variety in duty cycle and may need regular refills. The article below is interesting as when looking at dino gear oils wear did decrease with actual and laboratory aging. There are other other parameters, like 'micro-pitting' which also decreased with aging, 'scuffing' increased with aging but it seemed to be mainly a benefit for breaking in new parts. 'Pitting' did increase with aging. It'd be interesting to see if synthetic gear oils display the same attributes. M-28-02-339-HOEHN.pdf INFLUENCE OF LUBRICANT AGEING ON GEAR PERFORMANCE SUMMARY Five mineral oil based gear lubricants from different applications were aged at two different temperatures in a back-to back gear test rig under conditions close to practice. Changes in viscosity, total acid number (TAN), additive concentration, and particle content were analysed. Viscosity and TAN increased while additive components were reduced. The influence of the new oil and two different stages of oil degradation on gear wear, scuffing, micropitting and pitting was investigated. As a general tendency a substantial improvement in wear performance and a slight improvement in micropitting performance can be stated whereas a decrease in scuffing and pitting performance was found with continuous oil ageing. From these results a temperature-life curve for a mineral oil was proposed when a loss in pitting life of some 20% has to be expected. For mineral oils with sulphur-phosphorus additive packages this loss in pitting life is correlated to a viscosity increase of some 15 – 20%, a TAN increase of some 0.5 – 1.0 mgKOH/g and a decrease in additive concentration of some 30%. A test method, the PITS test, was developed that allows the evaluation of the pitting performance of a candidate lubricant relative to a reference lubricant under variable load conditions and enhanced continuous oil ageing.
It seems to be more marketing driven than anything else. Just like the 15K OCI. Most of the folks on the Bimmer boards change their fluids at more conventional intervals. None have reported any problems and most claim better/smoother operation. I'm not buying into the "lifetime" fluid either and changing out both the manual box (ZF) and diff with Speciality Formulations products. In fact, ZF recommends regular fluid change intervals on other OEM and replacement tranny applications. I don't believe that BMW gets a "special" ZF just so it won't need fluid replacement. I just think BMW doesn't want to pay for it as part of it's maintenance program. Wonder how many develop problems when outside of the maintenance program but still within the "lifetime" range? [crushedcar]
Well actually, ALL fluids are lifetime fluids. If you never change them, the life of the fluid and the life of the item (engine, gearbox, diff) will coincide very nicely. [Big Grin]
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