Oil - going from 0w20 to 0w40

[ShadowsPapa]

The manufacturer, ZF, states that the fluid and filter should be changed, depending on use between 50-75K miles.

Here is a video showing multiple ZF sources stating that the fluid IS NOT a lifetime fluid…

And yet I have shown the opposite in their documents. Go find my other posts.
There is more than just one ZF fluid. Maybe they are showing the other, cherry picking to fit their agenda. Lot of that on YouTube

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[ShadowsPapa]

 

[Hootbro]

Back in 2016, ZF recommended 80K to 120K KM (50K to 75K MI) change intervals on their 8 Speed Oil Change Kit documentation. By 2022 and with their latest 2024 dated PDF for the 8 Speed Oil Change Kit, mileage recommendations were removed.

That basically leaves their latest TE-ML 11 document dated 2026 now recommending a 150K KM (93K MI) change interval for the ZF 8 Speeds as @ShadowsPapa mentioned. This document is the first I have seen ZF use the term "Lifetime Fill".

Anybody recommending 80K to 120K KM (50K to 75K MI) change intervals is only incorrect in that it is outdated recommendations now having been superseded by 150K KM (93K MI) change intervals by ZF.

 

[Jrgunn5150]

Back in 2016, my Ram Ecodiesel was brand new.

445,000 miles and 9 years later when the block heater burned it to the ground, it still had the same transmission fluid in it.

 

[ShadowsPapa]

Back in 2016, ZF recommended 80K to 120K KM (50K to 75K MI) change intervals on their 8 Speed Oil Change Kit documentation. By 2022 and with their latest 2024 dated PDF for the 8 Speed Oil Change Kit, mileage recommendations were removed.

That basically leaves their latest TE-ML 11 document dated 2026 now recommending a 150K KM (93K MI) change interval for the ZF 8 Speeds as @ShadowsPapa mentioned. This document is the first I have seen ZF use the term "Lifetime Fill".

Anybody recommending 80K to 120K KM (50K to 75K MI) change intervals is only incorrect in that it is outdated recommendations now having been superseded by 150K KM (93K MI) change intervals by ZF.

And of course, as always - anything should be tempered with how it's used. If you tow heavy loads, in hills and heat - then reduce the interval down accordingly. Lifetime doesn't mean forever with abuse or harsh use.
This means for people like my wife - she could easily go 80-90K before any change. I tow, so I'd take that down a bit. I don't abuse it, or let it hunt gears constantly (that matters, too!!) - I'd not even think about anything less than perhaps 70K with my use. Heck, I've seen TF727s go 90,000 miles before a fluid change and even at that, it wasn't terrible. (I used to rebuild automatics in a shop I worked at - I saw all kinds from abuse to extremely mild use)

Fluids have changed a lot over the years. Technology has changed. Even transmission programming can impact needed change intervals. When they changed from downshifting one at a time, to two at a time, that helped extend the change interval - less wear. It's a complex situation that many without experience try to over-simplify (or worse, go by youtube or forum posts from people who really don't know)

 

[Rusty PW]

You guys still using Dino piss for oil. I use abiogenic oil.

 

[smlobx]

If you bother to read the actual publications posted above it says…


5-, 6-, 8- and 9-speed as well as 4HP20 automatic transmissions:


ZF 5-, 6-, 8- and 9-speed as well as the ZF 4HP20 automatic transmissions are filled maintenance-free with specially developed semi-synthetic ATF oils. However, due to the many factors influencing the service life of transmissions in individual operation, ZF recommends an oil change after 150,000 km for its transmissions. In operating conditions with high temperatures and loads, or with unknown vehicle use in the past, it can make sense to change the transmission oil at shorter intervals.

—-

please read the last two sentences…

 

[ShadowsPapa]

If you bother to read the actual publications posted above it says…


5-, 6-, 8- and 9-speed as well as 4HP20 automatic transmissions:


ZF 5-, 6-, 8- and 9-speed as well as the ZF 4HP20 automatic transmissions are filled maintenance-free with specially developed semi-synthetic ATF oils. However, due to the many factors influencing the service life of transmissions in individual operation, ZF recommends an oil change after 150,000 km for its transmissions. In operating conditions with high temperatures and loads, or with unknown vehicle use in the past, it can make sense to change the transmission oil at shorter intervals.

—-

please read the last two sentences…

We all did. That is exactly what I said in response to Hootbro if you read my response. Our point was that it does say lifetime, and it doesn't give the specific numbers otherwise mentioned - those are OLD and do not apply. So it's you missing the point.

Go read our posts again.
50K-75K is old, outdated information. It does use the term lifetime and does state shorter may be needed. Nope, we didn't miss anything.
Go read my other posts over the years.

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