[iqraceworks]

I’m going through my “new to me” 07’ 335i with 90K miles on it…getting all of the maintenance out of the way before I start adding bolt-ons.

One of the things I’d like to do is change the oil and filter in the transmission.

I’ve been reading through the forum posts, trying to dig up info….and there is a lot of conflicting into out there (and lots of arguing on the correct type of fluid to use).

I’ve found some posts saying that you never need to change the fluid. Some posts saying you should just flush it. Some posts saying that it’s ok to change it as long as it doesn’t have a lot of miles on it. Some posts saying that it’s really easy to change, just do it. Some posts saying that if the transmissions has high miles on it, changing the fluid might actually damage it? And everything in between.

I have no reliable history as far as if it’s ever been changed in the past. With 90K miles on the car, what should I do? Leave it? Have it flushed? Change the oil/filter myself? Other?

Also…..why does everyone replace the pan? Can you not just reuse it?

[nyt]

Originally Posted by iqraceworks

Also…..why does everyone replace the pan? Can you not just reuse it?

The filter is built into the pan, you have to replace it.

[rjahl]

Originally Posted by iqraceworks

I’m going through my “new to me” 07’ 335i with 90K miles on it…getting all of the maintenance out of the way before I start adding bolt-ons.

One of the things I’d like to do is change the oil and filter in the transmission.

I’ve been reading through the forum posts, trying to dig up info….and there is a lot of conflicting into out there (and lots of arguing on the correct type of fluid to use).

I’ve found some posts saying that you never need to change the fluid. Some posts saying you should just flush it. Some posts saying that it’s ok to change it as long as it doesn’t have a lot of miles on it. Some posts saying that it’s really easy to change, just do it. Some posts saying that if the transmissions has high miles on it, changing the fluid might actually damage it? And everything in between.

I have no reliable history as far as if it’s ever been changed in the past. With 90K miles on the car, what should I do? Leave it? Have it flushed? Change the oil/filter myself? Other?

Also…..why does everyone replace the pan? Can you not just reuse it?

If you find the posts confusing, try a real ZF transmission specialist.

THECTS.com is a good one to call.

California Transmission Supply, they specialize in ZF transmissions


Now for my advice;

There is no such thing as a lifetime transmission fluid. The lubrication properties break down with age and heat. Also the friction modifiers wear out. 60,000 change intervals miles seems to be the advice I've heard.

The friction modifiers is something I experienced and is well documented. Big problem with Jag and Hyundai.

The ZF Fluid is the correct fluid. I've used Penzion and the shifts where not as smooth as ZF. The trans did eventually adapt so I can't say it was harmful. Certainly cheeper.

Flushing is not needed and I'd avoid unless I was sure the flushing equipment was properly cleaned between jobs. Unless something is really wrong, you just don't collect that much dirt inside the case.

Simple drain and fill every 60k with new pan and integral filter assembly.

Simple procedure but a PITA to perform properly on jack stands. The filling procedure sucks.

[rjahl]

One more note:

Ask the transmission shop about the megatronic seal. As these cars get older these seals are known the get brittle , crack and leak. Allowing high pressure fluid to bypass your clutches and drain back to the pan. If bad enough you will not generate enough pressure to shift properly.

Worth looking into before you start making HP modifications.

Seal is cheap, like $20. If you already have the pan down for a fluid change.......

[addictedtoboost]

Originally Posted by rjahl

One more note:

Ask the transmission shop about the megatronic seal. As these cars get older these seals are known the get brittle , crack and leak. Allowing high pressure fluid to bypass your clutches and drain back to the pan. If bad enough you will not generate enough pressure to shift properly.

Worth looking into before you start making HP modifications.

Seal is cheap, like $20. If you already have the pan down for a fluid change.......

My transmission stated slipping real bad in third gear after 182k on a 335xi. I'll be having a used one with 70k installed tomorrow. I ordered the Mechatronic Service Kit from fcpeuro due to lifetime replacement warranty that comes with it.

[Devildog0905]

Originally Posted by iqraceworks

I’m going through my “new to me” 07’ 335i with 90K miles on it…getting all of the maintenance out of the way before I start adding bolt-ons.

One of the things I’d like to do is change the oil and filter in the transmission.

I’ve been reading through the forum posts, trying to dig up info….and there is a lot of conflicting into out there (and lots of arguing on the correct type of fluid to use).

I’ve found some posts saying that you never need to change the fluid. Some posts saying you should just flush it. Some posts saying that it’s ok to change it as long as it doesn’t have a lot of miles on it. Some posts saying that it’s really easy to change, just do it. Some posts saying that if the transmissions has high miles on it, changing the fluid might actually damage it? And everything in between.

I have no reliable history as far as if it’s ever been changed in the past. With 90K miles on the car, what should I do? Leave it? Have it flushed? Change the oil/filter myself? Other?

Also…..why does everyone replace the pan? Can you not just reuse it?

I would definitely change the fluid. Only use ZF fluid and parts. ZF makes the transmission.

I highly recommend the service kit from FCP euro. It comes with the pan, fluid, new bolts, and the 6 seals/sleeves.

BMW GA6HP19Z Mechatronic Service Kit - 24152333907KT3


https://www.fcpeuro.com/products/bmw-ga6hp19z-mechatronic-service-kit-24152333907kt3

All parts from FCP euro have a lifetime warranty.

[iqraceworks]

Originally Posted by Devildog0905

I would definitely change the fluid. Only use ZF fluid and parts. ZF makes the transmission.

I highly recommend the service kit from FCP euro. It comes with the pan, fluid, new bolts, and the 6 seals/sleeves.

BMW GA6HP19Z Mechatronic Service Kit - 24152333907KT3


https://www.fcpeuro.com/products/bmw...24152333907kt3

All parts from FCP euro have a lifetime warranty.

Thanks! I will have to get that kit ordered ASAP!.

[Tiron]

Changed the fluid/filter in my last 335 at 140k miles. I used Mobil 1 syn ATF, and it made a great improvement in both shift time and feel. I also changed the mechatronic sleeve and little rubber tubes inside at the same time. Make sure you take the fill plug out first to ensure it can be removed, mine was in there pretty tight and I would have been stuck with no fluid if I hadn't checked it first (got trans nice and warm and put ice cubes in the plug to shrink it to get it out).

Definitely would recommend, "lifetime" fluid really means "warranty period" fluid.

[9krpmrx8]

Yes, change it, changed mine at 75k and again at 100k, shifts like new, 108k now.

[ewicky]

I'd drain and fill with a new pan/filter. Then I'd do it again next year or after 10k. Mine was factory sealed at 112k, and it needed to be changed. I used Redline D6 and it works well for me. I didn't ever reset the adaptations. i just let the adaptations algorithm figure it out on its own over time, exactly like it's supposed to. Sent in samples from the factory fill and drained as well as my subsequent re-drain, and got a relatively clean bill of health from Blackstone.

[iqraceworks]

So Mobil1 ATF FLuid, Redline ATF fluid, or the OEM ZF fluid........looks like people are using lots of different types of fluid.

Is one any better than the other?

[MooreBoost]

Originally Posted by iqraceworks

So Mobil1 ATF FLuid, Redline ATF fluid, or the OEM ZF fluid........looks like people are using lots of different types of fluid.

Is one any better than the other?

I've never heard of anyone having issues with OEM ZF fluid. I've heard of people having issues with others and having to refill it.

If OEM ZF got you to 90k, and considering the above, I'd go with OEM ZF.

[Devildog0905]

Originally Posted by iqraceworks

So Mobil1 ATF FLuid, Redline ATF fluid, or the OEM ZF fluid........looks like people are using lots of different types of fluid.

Is one any better than the other?

Do yourself a favor and buy the ZF. It's more expensive but it was made specifically for our transmission. The only other trans fluid I've seen people use is redline d4 but the feedback is hit or miss. Our transmissions are way too expensive to take the chance on a different fluid.