[eff32fl]

Originally Posted by sspade

Directly from ZF:

Lifetime in most cases (maintenance free) but a good idea to change at 90k miles under harsh conditions or unknown history of use.

Read it and weep!

That's not what it says. It says they recommend an oil change at 90k miles. In more extreme cases with high heat or load doing it sooner is a good idea.

[Livetodrive]

My BMW service advisor stuck by the BMW policy that a transmission fluid change is not recommended and declined to do it. I then hung around until I found a more mechanically knowledgeable advisor. He agreed it should be done at my car’s mileage of 61,000 miles and agreed to do it.

To make a long story short, I ended up having the transmission fluid changed last week at a local indie BMW shop by an ex-BMW tech. He indicated that before draining the fluid they would take a sample and inspect it. If it was too contaminated they would not replace it. Mine looked good so they went ahead with it. The transmission felt the same afterwards with no issues. I had bought the transmission kit from FCP Euro beforehand and handed it to them. I also had the mechatronics connected sleeve seal replaced.

My take on all this is that “lifetime” fluid means about 100,000 miles. I bought my car new and want to keep it, so I had it done.

During the same appointment I also had the coolant, front and rear differential and transfer case fluids replaced. The brake fluid has been replaced every two years, per BMW recommendations.

[MidtownMike]

https://aftermarket.zf.com/us/afterm...assenger-cars/

[im_an_alien]

Originally Posted by MidtownMike

https://aftermarket.zf.com/us/afterm...assenger-cars/

Nowhere do they mention the ZF8 nor do they clearly state that's it's necessary and at what mileage. Like I said, clear as mud.
ZF says it's recommended. So do it if you want, don't do it if you don't want to.

[monster6a2]

Originally Posted by danb1979

I've had ZF boxes in my E39s serviced with zero issues afterwards; ones currently on 176k miles now (I had the fluid changes when I owned it at 130k miles); the 2nd one was changed when I owned it at 80k miles, it's now on c150k IIRC

My 2002 Jap import E39 touring was serviced at 82k miles, I sold it at 99k miles and its on 120k miles now, zero issues and my last E39, another Jap import E39 540i Sport saloon was serviced at 52k miles and 21 years old; the oil was a mess. The box was very much better after the service and its still smooth as silk now

I've also had the ZF6 boxes serviced in an E65 and F01 and both are still doing very well now and do a lot of miles from what I know

My current F31 is on 100k miles and I'll be getting in to be serviced when I've got 5mins to think...

ZF would not recommend the service of their boxes if they were to have issues; neither would someone like Grant at Automatic Transmissions, Preston, who as Ive said, has been around since the dark ages...

I'll go with what those folk say rather then Jim-Bob on the forums 'cos Daddy says so'...

Seems like I got a lot of people backing ‘what Daddy says’, including ZF for that matter. Maybe Jim-Bob might be right on this one.

In all seriousness though, this topic is heavily disputed in the auto industry as people practice what has worked for them in the past, like in your case. I was never saying you or your hometown specialist were wrong, because you weren’t. In a lot of cases, servicing transmissions is not at all a bad idea

For other applications however, it could be. There really isn’t a right or wrong answer because every application and situation is different.

I would however recommend that if your transmission has not had the fluid changed and there are a lot of miles on it, it is probably a better idea to not touch it
As ZF says, it’s maintenance free.

[eff32fl]

Originally Posted by im_an_alien

Nowhere do they mention the ZF8 nor do they clearly state that's it's necessary and at what mileage. Like I said, clear as mud.
ZF says it's recommended. So do it if you want, don't do it if you don't want to.

The link does specify the 8HP transmission.

[im_an_alien]

Originally Posted by eff32fl

The link does specify the 8HP transmission.

It does way down in the instructions (for those who decide to do it) but not in the general comments preceding. In other words the link is not ZF8 specific and does nothing to clear the muck.

[charlie fairmont]

Originally Posted by im_an_alien

It does way down in the instructions (for those who decide to do it) but not in the general comments preceding. In other words the link is not ZF8 specific and does nothing to clear the muck.

He's referring to the link in his post, post #6. I'll attach the PDF here, too.

[im_an_alien]

Originally Posted by charlie fairmont

He's referring to the link in his post, post #6. I'll attach the PDF here, too.

I was originally replying to midtownmike's link in post #25, otherwise my reply won't make sense lol
Maybe f32fl will tell us which one😁
This thread got hot fast, OP should tell us whether he's gonna do it or not...

[charlie fairmont]

Originally Posted by im_an_alien

...This thread got hot fast...

Never met a fluid viscosity or interval discussion on the internet that didn't

[Fliplegend]

So why are there so many threads about the transmission whining after a fluid change?

[MidtownMike]

Originally Posted by Fliplegend

So why are there so many threads about the transmission whining after a fluid change?

The transmission also whines a bit if the fluid has never been changed, especially when cold. Could just be that people pay more attention and listen more closely when the fluid has been changed.

The procedure to refresh is quite specific and a bit complex (cycle through specific temperatures and specific gears). Don't know about the Hamburger States of Freedom, but here in Europe ZF has appointed and trained specialist workshops listed on their website, who follow the process exactly. Could it be that the "horror stories" are from people who had it refreshed at a local workshop with little knowledge about European cars and ZF transmissions?

[eff32fl]

Originally Posted by MidtownMike

The transmission also whines a bit if the fluid has never been changed, especially when cold. Could just be that people pay more attention and listen more closely when the fluid has been changed.

The procedure to refresh is quite specific and a bit complex (cycle through specific temperatures and specific gears). Don't know about the Hamburger States of Freedom, but here in Europe ZF has appointed and trained specialist workshops listed on their website, who follow the process exactly. Could it be that the "horror stories" are from people who had it refreshed at a local workshop with little knowledge about European cars and ZF transmissions?

Mmmm hamburgers!

Yes it's anecdotal but someone was commenting on here recently that their tranny fluid got refreshed and it whined after. The mechanic swore up and down they did it right. The mechanic looked at it again and found it was a bit low on fluid and topped it off and no more whine.

[F32Fleet]

Originally Posted by micharlie

Is that true?

He said I quote

“We do not change/flush transmission fluid unless doing a transmission repair - the fluid is lifetime”

It is true. However, ZF had a severe service interval of 55k-75k miles which they've sorta back tracked on over the last couple of years.

[amancuso]

Originally Posted by MidtownMike

BMW is heavily dependent on the lease market (at least here in Europe). To keep the lease "affordable" and competitive, the maintenance cost needs to remain low. That is why the prescribed oil change intervals are ridiculously long and no transmission oil change factored in (blatantly ignoring the transmission manufacturer's recommendation).
By the time the negative effects start to show and shit breaks down, the car is out of warranty, so not BMW's problem.

The crazy thing about that is that the transmission maintenance should be under $500.00 every 60k or 5 yrs, even if you want to use the new numbers 100k or 10yrs or whatever. If you haven't looked up the procedure, it's more or the less the same method as it has been since the e36. The fluid/filter kit is about $230 +/- from FCP or similar, and the it shouldn't take a trained shop more than 2 hours to do, and that's being generous. Also most leases are 2-4 yrs, which would be outside the scope of a 60k maintenance.

[sspade]

Originally Posted by eff32fl

That's not what it says. It says they recommend an oil change at 90k miles. In more extreme cases with high heat or load doing it sooner is a good idea.

Really? It doesnt say that their gearbox is maintenance free under normal use cases? Where did you learn to read?!

[sspade]

Reminder on Blackstone's stance:

[rlesko]

I changed my transmission fluid around 110k miles and it was one of the best decisions I made. I did follow the guidelines about letting the transmission warm up and cycle through the gears, FCP has a great video on it. I filled it with the exact amount of fluid that was drained. It was a bit annoying to read the transmission fluid temp, as its a bit buried in ISTA.

The car's performance was immediately improved, with the shifts being much quicker and smoother. To anyone reading this- if your car has around 100-110k miles on it, its not too late. Change the fluid, you won't regret it (or pay someone who can do it properly).

I think you 'ought to be north of 150k miles to really think about not doing it for fear of disrupting something.