Automatic Transmission Fluid and Diff fluid

[SonnyA85]

How much of each will an 03 Z4 3.0 require?

I have handed the mechanic 8 litres of ATF and 1.5 litres of diff fluid.

He didn't think it was enough diff fluid. And he said he likes to have an extra litre or two of transmission fluid to flush the old stuff out completely.

 

[TheDan]

When I got my diff fluid done (pre LSD) I gave the mechanic a US quart (946ml) and it was literally the perfect amount (came to the bottom of the fill plug) despite BMW TIS saying its got a 0.85L fill quantity.



As for the auto box I am not sure, but for my manual I used 2 US quarts (1.9L) and there was nearly half of one of the bottles left over. I think from what I've read though that the auto box has a much higher drain and fill capacity because when its drained you will also drain the torque converter (with the engine off). TIS seems to indicate there is a 9L capacity including the torque converter.



Hope this helps.

 

[SonnyA85]

When I got my diff fluid done (pre LSD) I gave the mechanic a US quart (946ml) and it was literally the perfect amount (came to the bottom of the fill plug) despite BMW TIS saying its got a 0.85L fill quantity.

Screenshot 2022-07-02 111413.png

As for the auto box I am not sure, but for my manual I used 2 US quarts (1.9L) and there was nearly half of one of the bottles left over. I think from what I've read though that the auto box has a much higher drain and fill capacity because when its drained you will also drain the torque converter (with the engine off). TIS seems to indicate there is a 9L capacity including the torque converter.

Screenshot 2022-07-02 113817.png

Hope this helps.

Thanks.

He managed to do them both no issues. He even had a bit spare ATF to do a flush he said but getting the fill plug off was apparently a nightmare as it was seized and the position it is in made it impossible to get off without putting some real graft in.

If the transmission didn't have enough fluid I imagine it would overheat and let me know. I'll need to go for a long drive and see if it's okay.

See if I notice a change as well. A lot of folk have said it felt much better after a full refresh

 

[Rockhopper]

Conversely a chap on the Facebook group ended up scrapping his car just a couple of weeks ago as the gearbox never worked properly after he did a fluid change. I’ve heard this happen on several occasions as well

 

[SonnyA85]

Conversely a chap on the Facebook group ended up scrapping his car just a couple of weeks ago as the gearbox never worked properly after he did a fluid change. I’ve heard this happen on several occasions as well

Luckily I have one of the top transmission specialists in the world nearby. Who rebuild them as well as service. There was a news article about them which is how I found them so if I have any issues it would be going straight to them.

 

[Rockhopper]

Yes, this chaps car wasn’t worth the expense of doing that for him.

 

[Zulu4]

Conversely a chap on the Facebook group ended up scrapping his car just a couple of weeks ago as the gearbox never worked properly after he did a fluid change. I’ve heard this happen on several occasions as well

I've also heard of problems on VW forums when people have changed ZF fluids.

My take for auto gearboxes is "If it ain't broke, don't fix it".

Fortunately my Zed's ZF6 (66000 miles) and my Phaeton's ZF6 (126000 miles) gear changes are silky smooth. Much more so than my wife's ZF9 (50000 miles ) gearbox in her Evoque. Newer isn't always better.