ZHP Steptronic Owners Guide to ATF
The premise of this post is to share my experience with ATF on my most recent maintenance item.
Car: 2005 BMW 330i ZHP 5-speed GM transmission
Label Part No: 83220024359 (Texaco ETL 8072B fluid)
I'll try and add some information/guidance on the pros/cons I saw while performing my first ATF change on my steptronic ZHP with GM 5-speed transmission (Part# on my green/blue label was 83220024359 which calls for Texaco ETL 8072B fluid.
I searched countless forums about which fluids to use, the horror of using non-OEM fluid, transmission failure, internet opinions flying left and right, and recommendations from several oil manufacturers. I ultimately decided to use the ECSTuning kit since it was in one package (OEM filter kit with Redline D4 ATF). Redline D4 seems to be a winner on most bimmer sites and seems to mix well with the OEM fluid based on countless people who say they've tried it. Now, that being said I did not experience the same love for Redline D4.
I did a one time drain/filter/gasket/fill ATF change resulting in ~6.5-7 qts of new D4 fluid in the transmission (~9.5 qt capacity). I took it for the test drive afterwards and it felt like a dream. Shifts were hardly felt and selecting P/R/N/D was seamless. Now my transmission only had 83k miles so it felt great to begin with. The only change here was the shifting felt even better. There was one problem...From a stop with moderate throttle so the car would shift around 3-4k RPM I had a slip (between gears 1-2 or 2-3). All other operation of the car was flawless. This really irritated me, freaked me out, and made me dream about my car blowing up - resulting in my first manual transmission swap.
I even saw a 6-speed ZHP manual transmission with a few goodies on e46f.com classifieds. However, I didn't really want to go that route just yet considering I had a perfect transmission a week earlier and I didn't want to empty my wallet.
Even more research into the fluids and it seems that the Texaco ETL 8072B fluid was superseded by Dexron VI. Now there are plenty of people willing to argue about the correct fluid and I'm here only to state what I experienced first hand and what I used personally in my own car. Xoutpost.com was a great source as well as Bentley manual, parts counter, and other internet searching. I popped down to the local Oreilly Auto and picked up some Valvoline Dex VI full synthetic to flush out the Redline D4 I had put in previously. I did the drain/fill and got about 4.5 qts in. This meant I had roughly 47.4% Dex6, 36% D4, and 16.6% Tex ETL. A pretty f'd up mixture if you ask me and I'm waiting for the transmission gods to spite me and blow my car to smithereens.
Test Drive:
- Still had the 1-2 slip with moderate throttle.
http://farm9.staticflickr.com/8391/8...0b1939a9_z.jpg
ATF by seanpippin1, on Flickr
So my next step was another drain/fill (4.5 qts, fluid pump dying, trip to Walmart, button it up). This means my transmission concoction is now ~72% Dex6, 19% D4, and 8.7% Tex ETL. I'm getting closer and starting to loose patience.
Test Drive 2:
- A lot less noticeable slip.
- Driving around today I found it incredibly difficult to recreate the problem I was seeing before and the car feels like it did before the ATF change...beautiful.
Next steps:
1. Do a drain/pan drop/fill to hopefully get 6.5 qts in and make my mixture ~91% Dex6.
Lessons learned:
- I would do a 6.5 qt drain/fill (leaving the old filter in tact)
Replace old gasket/pan drive for a bit.
Do a 2nd 6.5 qt drain/fill (replace filter and gasket)
This method allows for pretty much all fluid to be swapped to the new fluid
- I would use Valvoline Dexron 6 on a ZHP GM tranny.
- I might even try Royal Purple MaxATF, but only if there were data showing how much better it was than Dex6 because Valvoline Dex6 is pretty cheap and in my mind quality.
Looking back I wish I had picked up the filter package from Autohausaz.com and grabbed the fluid at a local Walmart. I would have been done sooner, not had lucid dreams about my lovely ZHP blowing up, and a lot less stress.
Edit: OEM fluid notes:
- The fluid was a dark brownish color and smelled nasty. It didn't seem burnt or terrible, but it definitely wasn't opaque. The magnet did the job and had a small layer of metal, but not exaggerated. I now understand why ATF changes are important and I will be doing them more regularly (~30k miles).
Something else I'd like to understand is why Dex6 is a thinner (less viscous fluid) yet seems to work better than the D4. It could just be that D4 and Tex ETL didn't mix well I guess. Either way I thought that the transmission would've liked a more viscous fluid allowing it to function better. I do know that the Dex6 may be a thinner fluid but it has a tighter spec not allowing it to degrade as much as Dex3 could throughout its life. It's also supposed to provide better mpg because it is less viscous.
