Your Transmission Fluid is NOT "LIFETIME"

[dayasingh]

After changing the the transmission fluid the level has to be checked at a certain temperature, however, the transmission cooler valve will not be open at that temperature, is there a way to open the transmission oil cooler valve, so that there is no fluid stuck in the cooler that will later change the fluid level. What is a good scan tool/coding program that one can use for monitoring the fluid temperature. Here's a video link that mentions the cooler valve.

And here's FCP euro video that does not talk about the transmission cooler.

So what is the correct procedure for the F15 xdrive 35i

Appreciate the help.

[M302_imola]

^^^This is one of the many reason I've put off changing mine. Just to many damn hoops to jump through. Shouldn't be that difficult.

[turboawd]

The cooler will always be full of oil, whether the valve is open or closed. So that won't change the fluid level.

[scotty339]

Been needing to do this also, at 115k KM so probably due. Just waiting till I can use a lift. Not something I want to do on my back in the garage on jack stands.

[XxBBVTMxX]

I just changed my oil with a complete kit (bled) two weeks ago at just over 90k miles. It was fairly easy for a $303 DIY compared to Dealership telling me just north of $1k with no Pan nor filter change 🤦🏽🤷🏽

Put in new Pan, filter, gasket, bolts, ZF8HP OEM oil.

My oil looked clear Amber draining but when I removed the pan, you could see some shiny stuff in the oil. As I tilted the Pan away from the filter, more of that shiny stuff came out.. clearly, this filter was just done. Check out the picture of the Pan and the magnets. I'm the second owner, so don't know how it was driven before me.

[Ascotgrun]

The shiny stuff will be material worn off the steel bands. It's promising that your fluid looked clear after 90K miles.

[crystalworks]

Have the FCP (Liqui Moly) kit here ready to go on the wife's "new' 2015 X35d w/ 86000 miles. Having done 2 other servicings on ZF trans' I am fairly familiar with the process. Did a 6HP19 (e61 wagon w/ 195000 miles) and 6HP28x (e70 diesel w/ 166000 miles). Will be in the garage after I finish up the E70.

Just to add a data point to the "lifetime" fluid debate (what a crock). Our 2010 X35d experienced E clutch failure at 166,000 miles, well started at about 155000 miles. E clutch assists 4th gear and up. Anytime 4th is requested it jerks and "failsafe mode" is triggered, code 4F89 for 3-4 gear ratio monitoring. 1-3 gears had no issues. Tried a valve body rebuild (complete) plus tube sleeves and 3 different fluids before resolving to replace trans. Result of that is below, in case anyone is interested. Here is what the fluid and magnets looked like at 166,000 miles. Garbage, though fluid did not smell "terrible."



1. First try was Pentosin ATF1 - Thin fluid, similar to ZF Lifeguard 6 in viscosity and color. When driven the vehicle exhibited no change in shifting behavior, immediately slipping out of 4th and fail safe triggered.

2. Second try was Valvoline MaxLife Multivehicle - Thicker fluid, red color vs. golden of Lifeguard 6 and Pentosin. Trans actually made it into 4th a few times, though with a buck, but would eventually trans failsafe with more 4th gear requests.

3. Third and final attempt was Redline D4 fluid w/ a half bottle of Lucas Trans additive. This fluid exhibited the same behavior as the Pentosin ATF1 and old ZF fluid. As soon as 4th is requested, immediate trans failsafe.

The failures happen exactly as Sophisticated Redneck's failure. Requesting a gear drop on the highway (usually for passing) and the trans goes into neutral and a trans failsafe. Happened to us 3 times, fortunately with me driving all 3 times as I am not the type to panic. Threw hazards on immediately, merged right as opportunity arose to the shoulder, and finally shut off, restart, and drive away.

If you choose not to service the trans fluid, you fall into one of a few categories in my estimation. One, you don't intend to keep the vehicle to 200,000 miles. Two, you drive a vehicle into neglect and send to the scrapyard after enough systems have failed. Or 3, BMW has indoctrinated you into believing there is such a thing as a lifetime hydraulic fluid. If, you are like me (and most enthusiasts), service your transmission as ZF recommends. I plan on doing 75,000 mile intervals for any ZF equipped BMW I own from now on. If you choose not to do so, my situation will be yours in the future at some point. That is if you don't like scrapping nice vehicles or don't have the $5000 required to pay someone else or are too cheap to pay someone else to replace the trans. I am 2 of those.

Here's me after 3 days fighting to get the trans out of the E70. The diesel adds a ton of things to be removed, subframe dropping is involved. You have been warned.

[compsyndrome]

I am about to change my fluid, but I am baffled by the "drive until the valve opens" and "the overfill by 0.5L"

The bypass valve should be open until the temp hits 75C. Also, how do you overfill with the fill plug open?

[tlow98]

Listen to @crystalworks.

You should do your fluid. It’s easy. If a bum like me can change the pan and the fluid in about 1.5 hours taking my on my back under jacks stands… anyone can!

[Chilled]

Originally Posted by compsyndrome

I am about to change my fluid, but I am baffled by the "drive until the valve opens" and "the overfill by 0.5L"

The bypass valve should be open until the temp hits 75C. Also, how do you overfill with the fill plug open?

Not sure where you got those instructions. Just follow the instructions others have posted and/or the FCP vid.

[tlow98]

Originally Posted by Chilled

Not sure where you got those instructions. Just follow the instructions others have posted and/or the FCP vid.

Yep. Worked great for me following FCP instructions.

[compsyndrome]

Originally Posted by Chilled

Not sure where you got those instructions. Just follow the instructions others have posted and/or the FCP vid.

These ARE the instructions posted by the OP in this very same thread and are the instructions of the manufacturer.

[Chilled]

Originally Posted by compsyndrome

These ARE the instructions posted by the OP in this very same thread and are the instructions of the manufacturer.

I don't believe it, the one person who actual read the article, whilst most of us skip that part.

I retract my Que?.


That bit does raise an interesting question as the bypass valve only opens up at 90°C. I guess it means that once your at temp, and at the correct oil level (single drops) then add the 0.5L to account for the cooling circuit.

But, this seems like it would only apply to gearbox/cooler replacements where you drain the trans cooler.

Maybe reach out FCP Euro these guys are good at taking questions.

[compsyndrome]

Originally Posted by Chilled

I don't believe it, the one person who actual read the article, whilst most of us skip that part.

I retract my Que?.


That bit does raise an interesting question as the bypass valve only opens up at 90°C. I guess it means that once your at temp, and at the correct oil level (single drops) then add the 0.5L to account for the cooling circuit.

But, this seems like it would only apply to gearbox/cooler replacements where you drain the trans cooler.

Maybe reach out FCP Euro these guys are good at taking questions.

I think some of the confusion is how "open" is referenced. Since it's a bypass valve, technically, it's open when it's bypassing, meaning the cooler is sequestered. Often, however, people use open when it's "closed" and the circuit is "open" to the cooler.
The second part- now that I did it- if you're quick enough, you can overfill with 0.5L and maybe lose only 25% of it leaking out.
But I do think you are right- that overfill process doesn't apply if the cooler was not drained, which it is not by just changing the sump cover and oil.

[Chilled]

Just watched that university guys vid above, he does mention the oil cooler and the fill process for it.

So in a nutshell, yeah. If you drained the cooler/have never had it filled you will need to do the initial fill, check(page 4) + 0.5L(page 3). Then take it for a drive, let the bypass valve open, and flow oil into the cooler. Than let it cool to back around 30C, and go through the check process again where the oil is between 40-50C.

If you look at page 3, it has a truncated version of page 4 steps in it up until the Transcooler question.