"Lifetime" Transmission Fluid (Myth?)

I want to change the transmission fluid on my '06 BMW 550i which has about 60k miles. BMW (and its dealer), however, strongly advise that I not do so, saying that the factory fluid will last the “lifetime” of the car and that I may cause a malfunction by doing so. ALL transmissions need new fluid at some point, right? How can it hurt? BUT, the BMW team is sincere and they sure know BMWs. What should I do? HELP!

The factory maintenance schedule for my wifes 02 Sonata calls for 105,000 mile transmission fluid changes. Not going to happen. I change the fluid every 40K miles.

Some owners manuals have a surprising amount of do it yourself info.

The manual for her Sonata has detailed instructions for changing the fluid including a diagram showing the location of the drain plug.

The Sonata does not have a replaceable filter, so fluid changes are as simple as draining & replacing 5 quarts.

Take a look at the DIY section of your owners manual.

The LIFETIME of the car…right up till the thing burns up. Yep, that’s the end of the lifetime of the car !

Same gripe I have with those “lifetime” ujoints, wheel bearings, tie rod ends, ball joints, etc.

BMW is big on this. Ask them if the transmission has a ‘lifetime’ guarantee!

You may want to find some BMW forums for (much) more in-depth information on this issue. It’s a hot button.

I too suggest visiting some BMW forums.

My vehicle also has “lifetime” tranny fluid. I’m honestly not sure how I feel about it. Even years ago, before modern tranny technology and modern fluids, few people ever changed their tranny fluid, and except for speceific models known to have problems trannys rarely failed. I’m inclined to think “lifetime” fluid may be a modern reality.

I’d be interested to hear from Transman on this if he happens by.

Toyota has the same thing…They use a WS (World Standard) fluid. Toyota also recommends NEVER to change the fluid…I changed mine anyways at about 100k miles…It was FILTHY…I’ll NEVER leave it in there that long ever again.

I suppose to BMW, a company known for their cars constantly being leased, figure 3~4 years is a lifetime.

It’s also the reason BMWs have poor resale value. They are not likely recycled through 4 owners, like US and Japanese cars.

There is no such thing as “Lifetime transmission fluid” Dealers and manufacturers will tell you there is to sell their vehicles. Now, when you come back down to reality, you need to change your fluid and filter every 25-30k miles. Ask any transmission tech. Unless you have an extra $5-$6k to give BMW for a new one, I would highly suggest maintaining your trans on a regular basis. ALL ATF gets contaminated, ALL ATF is subjected to heat and breaks down over time. BMW is no different than the others.


Transmission fluid should be changed every 30k miles. It’s the cheapest transmission insurance you can buy.

That “lifetime” fluid is just yet another one of those misguided recommendations by the car maker to make your car appear to be more “maintenance free”. Recommendations like this are designed by the marketing department as a PR stunt.
Many car makers do the same thing and not just with trans fluid.

If they feel so strongly about lifetime fluid then let them warranty your transmission for the life of the car. Ask them that question and I assure you that you won’t get a simple yes or no answer to that one.

We hear about a lot of transmission problems here. Nearly all of them involve a transmission that had not had a fluid change in 100,000 miles. Many of them blame the problem on getting the change. What really has happened is they waited until the transmission was beginning to act up and then they changed the fluid and a couple of thousand miles later it crocked. It was just too late by the time they changed it. If BMW will warranty the transmission for life, then great, don’t change it, but I suspect they are not doing that.

Bavarian Auto’s newsletter just had an article on this debate, their conclusion: Lifetime means the lifetime of the transmission, when that dies so ends the fluid’s job. I agree. I would change it. It is cheap and easy to do, and if nothing less you have piece of mind knowing it is done.

Thanks for posting Transman. I value your judgement on this.

I had the same experience with my daughters Corolla, except I caught it at 70k. Toyota is wrong about that fluid, but worse yet, in the new 5 speed autos, it can’t be changed or even checked without a special machine.

Exactly… Lifetime of the transmission… If these manufacturers would replace your transmission when it expires, then absolutely, dont ever change the fluid and filter. But if I am going to pay for a new transmission when it goes then you can bet I’m going to take care of it to make it last as long as I can.

Like Joe was saying, we hear a lot about transmission problems here and a lot of these people say “Well, the fluid hasnt been changed in 50k, 60k, or has never been changed, Do you think changing the fluid will make work right again”??

More than 75% of the automatics crossing my bench are there due to improper or lack of service. Servicing your trans every 25-30k will still cost much less than replacing or rebuilding your trans.


maybe you should take some pictures of the insides of those 100k mile, no service, transmissions and post them online. :stuck_out_tongue:

Interestingly enough a friend sold his VW Golf with neglected timing belt/snapped with lifetime auto tranny fluid at 155k miles. The mechanic who bought the car stated the fluid was in decent shape considering the mileage. The transmission shifts and also shifted quite nicely.

Personally my guess is this fluid lasts somewhere between 150k-200k. I believe many regular non-lifetime fluid cars go at least 150k without a transmission repair.

I recently had a customer who was trying to deceive me concerning his Explorer. He said he always his own trans fluid and after getting into the owners manual it says the fluid does not need to be checked and is a lifetime fluid.

He had claimed he checked it with the dipstick but there is no stick. The way to check it is to go to Ford, get the trans fluid temp to a certain value or degree and remove the plug. The only way to know the correct temp is to connect to a computer. If a slow steady stream comes out it is good. If it comes out to fast or to slow it is not the right temp. Go figure!

I own three BMWs and have a mechanic that I really trust.

He says that the “lifetime” transmission fluid is just for marketing and suggests replacement at 50k intervals. My '04 330 is BMW Certified to 100k miles, so I will let that go so that BMW can’t say that I was not playing by their rules, but at 100,001 miles, it will get its tranny fluid changed.