[FCP Euro]

Great write-up. This will make the job easier for everyone.

[jimk]

Well, according to some more research I did, it looks like the 335i manual trannies use the BMW MTF-LT-3 fluid which in reality is a very light but stable viscosity ATF. The Red Line equivalent is now the D6ATF.

http://www.redlineoil.com/news_article.aspx?id=13

[akak1997]

I'm about to do change the tranny oil to Redline D4 ATF on my 135 manual, and I've saw a post saying tranny oil should be changed at a certain temperature so that you won't over/under fill it. Is that true? if so, any one know that temperature I should do it at? Thanks

[AlanAZ]

Is that true? if so, any one know that temperature I should do it at?

I find it difficult to believe that the gearbox capacity will change much with temperature. Bentley recommends driving a few miles before draining, I think more to suspend the sediment in the oil than for temp, same reason as engine oil. It's more important that the car is level.

I drove to lunch then back before my change, 20 mins total, oil was warm when it came out, not hot. It takes a while to get the car jacked and the under-cladding off. I let mine drain over night, as I felt it was important to get as much of the old oil and sediment out (and I changed to RP Synchromax.) I overfilled it a bit and waited for the excess to stop draining/dripping before buttoning it up (about 15 mins.) I replaced the bottom plug, but reused the top one, I wanted to be sure the drain plug didn't leak or fail.

Well worth doing, my car had 63K mls and the shifts, esp. into 2nd, are MUCH better. I'll probably change at 30-40K intervals now.

Update: I changed the Sychromax out for Redline ATF, the smooth shifting with Sychromax did not last.

[creaminz]

how much different 335i Automatic tranny would be to do?

[khafner]

I have not done the auto tranny in the new 3 series but in general and in other bmws you need more to change the fluid. Most don't have a drain plug and even if they did you should change the filter in the tranny when changing the fluid. So first the bottom of the tranny is removed, and yes fluid comes pouring out. If you drop one corner first (loosen all bolts then pry a corner down it makes getting the fluid out easier then remove the bottom pan. If you got the filter before hand you'll figure out how to change - usually two bolts hold them on. Clean the pan, put the new filter on, put the gasket on the pan with your favorite glue and reattach. It is important not to over tighten the pan bolts as they strip easy. Then fill. Most bmw's don't have dipsticks so fill till comes out fill hole. If possible I'd recheck a few days later and make sure level was correct. Auto trannies should have fluid changed more often then manuals as they run hotter and have pressure plates (similiar to a clutch) that engage and disengage. These wear and the wear products plug the filters up. This lowers the pressure in the tranny and they run even hotter and slip more and thus more wear. I'd never let an auto tranny go moe the 30,0000 miles without changing fluid and filter.

[bioman]

Can you use Synchomax in a MT 325i as well?

[hun77777]

what would u suggest we AT guys use on our tranny and how many qtz?

[AlanAZ]

Can you use Synchomax in a MT 325i as well?

Yes. I'm running it in my 325i, and way better shifting than factory. I don't know how it compares to Redline. Exact same process for changing. Mine took about 1.7 qt.

UPDATE: I've swapped out the Synchromax. The great shifting it provided only lasted a few months, then was about the same as the factory fluid w/60K miles on it.

I put in Redline D4 ATF for use in the Phoenix extremely hot climate. According to Redline tech support, D6 ATF is closest viscosity to the factory fluid and is recommended, espec. in colder climates (D6 is about 10% thinner than D4, so not much difference -- Synchromax is a heavier viscosity than even the D4.)

[NiVeDh]

What's the part number for the fill / drain plugs?

[AlanAZ]

Realoem.com. You need to input your VIN number to ensure the parts numbers are correct (corrects for any running changes during the manufacturing year.)

[uncle ben]

I just wanted to say that this is a great DIY thread.

I am considering running the RP Syncromesh in my manual transmission but do not know how cold weather will effect this fluid. Would i be better off running the bmw MTF-LT-3 due to the cold winters here in canada, or would the Royal Purple be fine? Thanks

[AlanAZ]

I am considering running the RP Syncromesh in my manual transmission but do not know how cold weather will effect this fluid. Would i be better off running the bmw MTF-LT-3 due to the cold winters here in canada, or would the Royal Purple be fine? Thanks

I can't answer that since I'm in Arizona. But I'd suggest that the Redline fluid for your gearbox (it's one of their AT fluids) would be better than the BMW fluid. Turner Motorsport put Redline in my E46 MT gearbox when I lived in Boston and it was much better than the factory fluid in the cold.

[danneldl]

is it the same on a 320d?
they say in sweden where i live that i shuldent change tranmission oil??
is this tru?ore is it better if i change oil on my gearbox?

[BKV122]

I just changed my manual trans fluid to redline d6 atf in my 330xi with 61,XXX miles. The job its self was very simple only problem was with redline bottle tops not fitting the screw on hose i bought from Pepboys and the seals on the bottles to were a B*tch to get off! Anyway i had to transfer the redline fluid into a empty and cleaned out oil quart container which fit the screw on hose fine.

Anyway when i drained my fluid it came out black and dirty! This was a change at a little over 61,000 miles.

[Nr!qUe]

What about for the 328?

I'd like to change my fluid, is there any difference with the transmissions?
What type of fluid should i use?

[rkg]

Just changed the trans and diff oil on my 330 with 40K. I had access to a friends car lift, so the job was even easier.

Do not forget to clean the magnetized drain plug of sediment. The oil was very clean and used Redline D4 in the trans and 85-90 in the diff. Overall, slightly better shift from 1st to 2nd ... nothing major.

[BrianMN]

Bump for this DIY! Just did it...super easy and it feels great!

[ton741]

I just did mine today, shifting is more smoother. Thanks Mr. 5

[Rotary Rasp]

Has anyone replaced their MT fluid with bmw oem fluid?

[Crusader]

Great post. Are the drain and fill plugs the same on the 328 6sp? IIRC, its a Gertrag while the 335 has a ZF. As to replacement fluids, Synthetic D4 is the best match for the factory fill and provides the smoothest shifting, particularly in cold climates (Redline or RP are excellent). For better lubrication and protection, Redline MTL will serve better, BUT it requires slow hands till the tranny warms.

[mirbahabmw]

can someone please let me know with certainty what REDLINE fluid (D4 ATF or D6 ATF) do I put into my 2009 328xi??? I really really need to know this. Thanks.