michael.d.s.

Finally an answer regarding lifetime filled transmissions !

105 posts in this topic

Ok this argument has went on long enough, I contacted ZF and this is what they said,

Hi Michael,

"Lifetime" fluids are just that, a lifetime lubricant that does not require change in a specified lifetime.

To explain further, the general terms or conditions result in an average lifetime of a passenger car of 10 years or 200,000Klm's ( or roughly 125,000mls ), so your fluid should be changed at these points to ensure good service life of your transmission. Should you decide ( as many do ) to change the fluid more regularly then this will not harm the transmission life, in the same manner, the oil is produced to last the above times & the oil companies would argue that changing the oil at lesser intervals is of no added benefit. To this matter, it is really personal choice wether or not to change the fluids at lesser than the above specified.

I hope the above helps to explain the term " lifetime" fluid.

Thanks & Best Regards

Darren Hayward

Service Advisor - Transmissions & Steering

Commercial Vehicles & Passenger Cars

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Hi,

Nice to get some authoritative feedback from specialists like that. However, looking into it a little further, and from what I was told by various specialists, is that other components are typically what fails - I've mentioned it before but I'm a bit vague, some sort of spline or shaft that gradually deteriorates over time and disintegrates. When it fails it fails. The gearbox fluid may well 'still' be in good condition etc or as per above, have a good amount of serviceable and performance life left in it to go well beyond the 'reasonable lifetime timespan given of 10 years/125,000 miles' - but to change that part means splitting open the box so you might as well renew everything. So theoretically, it shouldn't harm the transmission, however in practice as other bits wear and disintegrate the risk of failure builds up. This falls within the often reported scenario where someone has decided to change their gearbox fluid at say 85,000 miles with no history of issues previously, and then upon rebuild, it's failed a few thousand miles later. Theories seem to be that the disintegrating 'bits' are somehow 'gluing' the fluid to work well, and when fresh oil is used as it's thinner that 'gluing' effect (sorry don't know how else to describe it!) is lost and the gearbox has failed. Then the other end of the scale where theres examples of original transmissions working fine and mileages up in the 250K range with no fluid changes!

Boils down to the fact no one can definitively say a gearbox will or won't give up should an oil change be carried out or not carried out! - if you have an autobox, continue to drive it as is until you do get a problem!

Cheers, Dennis!

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Yes dennis its well documented that components within the box have their weaknesses, however the fluid itself doesn't have any way of preventing mechanical failure if changed or instigating it.

this is the point i am making.

Also I feel there is no one more specialist than the people that actually build these transmissions, no amount of gearbox specialists can really better that.

The reason for this thread is due to people on this forum stating that if I service their transmission for them, this will result in mechanical failure, It has came from the horse's mouth so to speak.

thanks

Michael

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Well Michael, my manual box certainly feels slicker (when warm at least) after the fluid change and my car has a genuine 75k miles on it. No idea if it'll last longer but it has most definetly benefitted from it.

Job well done mr!

:wink:

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The reason for this thread is due to people on this forum stating that if I service their transmission for them, this will result in mechanical failure,

Michael

Come on mate ..its just a few individuals who think like that,majority of us have faith in your work ,appreciate all your help in the past and know how things works in practical life.

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The reason for this thread is due to people on this forum stating that if I service their transmission for them, this will result in mechanical failure, It has came from the horse's mouth so to speak.

thanks

Michael

I certainly don't think that for one minute, in fact not even for one second!

I know that you know what your doing, and if you do a fluid change on my transmission and it fails in a few thousand miles, there is only one possible reason It was going to fail anyway!.

Correctly changing the fluid won't make any difference to that fact - If your just changing the fluid, how the hell could you know it was a waste of time, unless the gearbox was already exhibiting a fault when driving? Anyone with more than two brain cells should be able to figure that out!

If the fluid change was done by a halfwit or someone that simply didn't know how to do it correctly then I could see the arguement, but NOT in your case!

Regards

Eddy

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Let me advise you Turv....

At 10 years + you tranny oil will be black!!

If you follow my thread on the E60 tranny sump change,my oil at 6 years old was heavily contaminated,what went back in was honey coloured in comparison..

But like you say,its personal choice but let me ask you this.Would and do you apply the same principle to your engine? The oil in an auto tranny is given a similar amount of wear and tear within its components..

Its perfectly safe to change the oil in an Autbox as long as procedure is correctly applied,there is no "black art" its just an oil and filter change..

Its a no brainer IMHO..

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Tell him feck all fella, make your own mind up with your own judgement and from the wealth of knowledge that can be gleaned from many a source on here. At the end of the day, its your car and your choice if you want to replace gearbox oil or not. And if it does all go tits up at least you will have at least two people who can rebuild the box :lol:

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Ok this argument has went on long enough, I contacted ZF and this is what they said

Michael, have you tried contacting GM for their take on it? IMO the GM box used in the E39 diesels is not as well made as the ZF units and I fear that the 'lifetime' of the oil used in them is not as long as that of ZF.

In my case changing the oil certainly didn't prevent the inevitable failure, but that was at over 150k miles

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Let me advise you Turv....

At 10 years + you tranny oil will be black!!

If you follow my thread on the E60 tranny sump change,my oil at 6 years old was heavily contaminated,what went back in was honey coloured in comparison..

But like you say,its personal choice but let me ask you this.Would and do you apply the same principle to your engine? The oil in an auto tranny is given a similar amount of wear and tear within its components..

Its perfectly safe to change the oil in an Autbox as long as procedure is correctly applied,there is no "black art" its just an oil and filter change..

Its a no brainer IMHO..

So what do you want me to tell my specialist? that he is a complete moron? this is his day job, that he's done year in year out, re built no end of zf boxes.

Dunno what you have to tell him.. But that was my advice to you,not him...

Im no noodle myself as i have been in the motor trade for 27 years,over 20 of them being a head technician and a few of them working for Ralliart so i try and offer advice with experience to back up.

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IIRC BMW stated that 'lifetime' was 150K (don't know how many years)

Mine has been done twice going by my receipts and I've done it myself once.

It's still on the original box atm, a little bit sluggish shifting into 5th but after 300K it's not bad...

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Mine is 170k now ..., really worried about changing the oil it as it's a massive bill if the bad oil is doing a great job already holding the 'box together lol

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As I already said, I dont care what zf say. I would rather take the opportunity to have a new filter and clean oil in my box. I have read enough to have complete faith that nothing MDS will do will harm my box. OK, it may not make a difference to my 95k box now but I believe it will long term.

Sent from my X10i using Tapatalk

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My comment about the specialist being scared to change it was a joke-hence the tounge in cheek comment after it ;)

I was speculating as were you. You were not backing up your claims with any facts about failures of the boxes...but now we have an official ZF response to help counter your specialists belief. He could use that a sales angle himself to get customers to change their box oil now ;)

The main point here is we own £30-50k cars from new. They are now on their way out (let's not kid ourselves!) and are mostly 90/100k+ mileage some much more. So we are far exceeding the lifespan of other Marques of those years on the whole. I mean when is the last time you compared your 5 series to a 1999 Mondeo or Vectra with similar miles? 9/10 the difference would be vast in quality and condition (aside from being heavily detailed and no expense spared).

I will give you an example. I've a friend of the family with a fully loaded 750 BMW with 175k miles. He's had his box oil done at 100k and 175k. Still works fine. And the car has been into BMW every year with no expense spared on servicing and part replacement. It's even had a new engine. The dealers master technician told him it was wise to change the oil given the crap he has seen on the magnets before now...

I see your point and again thank mike for taking the time to get a 'life' expectancy from them.

I hope my change gets me another year of hassle free super comfortable motoring. If not I will buy a new car!

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Slooby, I have contacted GM but still await a reply.

Turv, you haven't hurt my feelings don't worry, and you can tell your friend whatever you want mate it really doesn't matter,

The point I make is that your friend like myself rebuilds and repairs these units, however please feel free to show him the email I got as obviously you would agree that the manufacturer knows better than him or myself, and if you noticed that ZF actually corrected me as I quoted 93,000 miles instead I should have quoted 125,000 miles.

Oil doesn't have frictional properties, it has lubricity and non-compressibility and it certainly doesn't prevent or promote mechanical failure, it merely restores some of the performance of the unit and reduces wear on internal components.

Cheers

Michael

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It's an interesting debate.

I had the fluid changed on my e36 some years back (which I believe is a GM tranny?) at approximately 100k miles on a 1992 car which was over 10 years old at the time. That too was supposedly lifetime fluid. I didn't have the filter changed as that would have made it an expensive job.

I've attached the write up. I was surprised at how clean the fluid was that came out.

I never had any issues following the fluid change.

Personally, I can't see how changing the fluid would do any harm - however all this chat about it is making me nervous, especially as there's nothing wrong with my 330's tranny at all at the moment.

Out of interest Michael, how do you do the fluid change without ramps? It must be difficult getting the car up off the ground and level - and also so the car can be run in drive? Or does that not need to happen for the ZF boxes?

Good to see ZF's stance on things though. Nice one.

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Oil doesn't have frictional properties, it has lubricity and non-compressibility and it certainly doesn't prevent or promote mechanical failure, it merely restores some of the performance of the unit and reduces wear on internal components.

I'm sorry Michael, but unless you can back that up with a string of equations to prove something other than the point you've made, it's irrelevant.

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The e36 wasn't classed as lifetime fill and used atf dexron fluid and you actually changed it before it was due, but there is every chance the fluid will seem ok at the same time there is the chance it will be black and burnt, It is merely to show that "lifetime" doesn't mean forever.

Nice write up btw :)

I equally raise all corners of the car about 18 inches off the ground, its easier than a ramp because I need an assistant to operate the selector. I use long hoses and pumps.

Dan Im not biting :lol:

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Ah I see.

I think this is also part of the problem. I had BMW dealers telling me different things at the time. Some saying yes change it at inspection2, others saying that it was lifetime and didn't need to be changed - if you then couple that with independents having their own opinions, and the forum based opinions, anyone trying to decide what to do is going to end up utterly bemused.

Write up was not one of my best tbh, as I wasn't actually doing the work myself - just making note of what the tech was chatting to me. :lol:

Can you also clarify something for me please.

The transmission fluid filter. Where is that in the grand scheme of things? In my mind, the filter would be there to prevent swarf and shit getting anywhere near bits that might be detrimentally affected by such muck. As such, draining the fluid from the sump (which should be where all the rubbish is) would mean the junk comes out with the fluid? Then the filter (which is there to capture rubbish) is also changed for a new, clean one - so more rubbish is removed when the old filter is taken out of the equation?

with say 50% clean oil put back in the sump, and a clean filter put in place, how is this supposed to be viewed as allowing crap into the delicate workings of the transmission?

I must be missing something.... :?

Apologies if this is posing questions asked previously.

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People pay to have a tube stuck up their bum to clean themselves out and have water thrown into this area to clean it out. Its probably not really needed but hey its something that makes you feel better and does not kill anyone. Its about the feel good factor.

Turv-no offence was meant by my post so please stop making reference to it as being some sort of witch hunt of your specialist (who nobody knows the name of/location etc!)

You are just as entitled to your opinion as us, we have listened to you however there is more 'experience' telling us it should be done. Including some dealers and techs. One dealer told me to get it done but 'not here as we will charge you the earth!'

I would be happy to take a sample from my box along with some new oil and send it to a university to have the two compared and eat my words!

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I've contacted an oil testing lab to see if they will take a sample from mine, compare it to the new oil and explain what they find in a report which we can hold on here as a sticky. This should help explain (if of course if it shows anything) as to whether it is beneficial (which we all expect it to be) and can help us make an informed decision from another 'expert'.

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Tell him feck all fella, make your own mind up with your own judgement and from the wealth of knowledge that can be gleaned from many a source on here.

Don't confuse an opinion on the internet with knowledge.

A lot of independent garages are reluctant to change high mileage cars auto fluid for a very simple reason - If it goes pop a short while after, they'll get the blame and be expected to pick up the repair bill. And as you've said yourself, "it's just an oil and filter change, it's a no brainer", but the owner is usually looking for someone to blame. Which is understandable, as it was working perfectly previously....

And you can bet your bottom dollar that you'll read it on the internet from the owner about how they fecked up his gearbox, and everyone will gain this useful "knowledge" that you speak about from someone with an axe to grind. :mrgreen:

( just an opinion from someone with 24 years in the "trade", and who changed his gearbox oil at 186K miles :D )

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^^

So you're opinion is change the fluid, yeah?

I agree - 90% of stuff online is going to be bitchin' and moanin' because something went wrong, and is not a fair representation.

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