[evilchargerfan]

The purpose of this post is to share my experience changing Transmission Fluid, and Pan. The usual disclaimers apply ... break your car, not my fault ... yada yada.

I'm not sure if this thread will be considered as a good or poorly written DIY, but here goes! (NOTE: I am open to suggestions, editing where necessary, and those with talent feel free to help me annotate photos)




Our patient is a 2012 BMW X3 35i with 119K miles. Original owner has little to no service records, so we can assume its all original fluid.



For convenience, I purchased a kit from FCP Euro:
https://www.fcpeuro.com/products/bmw...-24118612901kt
-ZF Pan/Filter Kit (Kit = oil pan with filter, oil pan gasket, oil pan bolts, fill plug)
-Liqui Moly TOP TEC 1800 ATF (I chose Liqui Moly because it's cheaper than ZF fluids. Either or, works)



I printed out the following to assist me throughout the day:
"ZF fluid change instructions si-zf-si-oelwechselkit-8hp-50130-en.pdf"
https://x3.xbimmers.com/forums/attac...8&d=1592506618


Parts list:

- 7 quart of trans fluid
- pan/filter and misc hardware (for those doing more than drain & fill)
- fluid transfer pump
- torque wrench
- ratchet
- 8mm hex socket
- 10mm hex socket
- T40 torx socket
- gloves
- shop towels
- an oil drain pan
- a means of keeping your floor clean (ie: tarp)

- optional: foxwell scan tool or ista+, to perform oil balancing at the end


Pre Requisites:
-jack up car by preferred method
-remove any under panels to access transmission pan
(I will not be covering the above 2 steps)








Credits to EndOfAnEra for creating such helpful threads that inspired this one

DIY: Let's change our front differential fluid
https://x3.xbimmers.com/forums/showthread.php?t=1736940
DIY: Let's change our rear differential fluid
https://x3.xbimmers.com/forums/showthread.php?t=1736681
DIY: Let's change our transfer case fluid
https://x3.xbimmers.com/forums/showthread.php?t=1736224




* * * to be continued * * *

[evilchargerfan]

A view of how things look from the rear end, looking towards the front end. Towards the "upper right" of the rectangular shaped pan is the drain plug, and to the "right" of that, off to the side is the fill plug.


For those doing a drain & fill, it would be a good idea to undo the fill port first


Some fluid spilled out, because my ramps are not 100% level


I then drained more fluid via the drain plug


Once the fluid stops, I began to undo the pan bolts


Notice how I left the front end bolts in place. This is so I can "tip" the pan and drain more fluid


Roughly an hour in, the pan is off!


About 5 QT collected


As expected, the pan was filthy


As were the magnets, yuck!





* * * to be continued * * *

[evilchargerfan]

New pan installed, bolts were finger tightened

Note the piece of paper? That image guided me to torque in the correct sequence. Each bolt torqued down to 10 NM.

Load fluid into your fluid transfer device of choice


Fill until fluid starts to overflow out of the fill port, then plug fill port (snug).


I followed the ZF recommended steps as best as I could:


-Place car on jack stands so wheels can spin freely (ensure all is level of course)

-Start the car

-Check oil temps, 30C-50C is acceptable


-Depressed the accelerator and held at 2k rpm's for 30 sec


-Shifted into Neutral and then checked oil temps to ensure I am not above 50C. Idle'd for about a minute


-Shifted to P and waited 10 sec


-Shifted to R and waited 10 sec


-Shifted to D and waited 10 sec


-Shifted to M1/M2 and waited 10 sec on each






-Shifted to P

-Checked oil temps again, this time I hit 51C and had to grab the shop fan and cool things down for a few mins




* * * to be continued * * *

[evilchargerfan]

For those following along still, thank you for putting up with me!

One thing I'd like to speak on is, the steps do ask for engine to stay running during most of these steps. I was working solo so I chose to turn off the car anytime I went underneath.




UPDATE AS OF 11/21/2020:
-DO NOT TURN OFF THE ENGINE
-DO NOT SKIP STEPS
-I WENT BACK AND WAS ABLE TO FILL ANOTHER 1.5L
-REPEAT ... DO NOT TURN OFF ENGINE, DO NOT SKIP STEPS. YOU WILL BE LOW ON FLUID








* * * Continued * * *

-After temps went down to 50C, I turned off the car and went below

-I opened up the fill plug and no fluid came out

-I then topped off another QT (ish) until excess fluid came out

-I closed the fill plug and torqued down to 35 NM

-I let the car idle for a few mins and did not see any leaks

-Then went for a brief test drive, came back and parked it with cardboard underneath. Checked the next morning, and no signs of any leaks (yay)


THE END








Special Note:

For those of you who have ISTA+ or a Foxwell Tool, you may notice a more strict process for doing the oil balancing. I chose to skip this path. If i had a 2nd person to help me, and a proper lift, I would have most definitely followed the Oil Balance steps

For fun, I did go through the steps in Foxwell and I will say, staying within the right temp range is hard! It doesnt take much to get the car too hot and the process stops you dead in your tracks ... so please do this job on a cold day

[evilchargerfan]

For those interested in following the Oil Balance Procedure:


Service


Drive


Transmission Control


Transmission Oil


Oil Balancing


Read, then OK


It asks the reason, in my case reason 3 was the best option


Make sure wheels can spin freely and apply parking brake!


This is where I had to "call it", because I didnt like the idea of doing this step without a 2nd person to help me fill from underneath while I sit in the drivers seat


This is me not waiting for the idle to drop down from 1k to 550-800 rpm range



* * * to be continued * * *

[evilchargerfan]

As per usual, temps must be in the 30C to 40C window or else it wont continue


I happened to be at 46C so I had to wait a while for things to cool down


Once cooled down, I had to start over and repeat a few prev steps, until I got to this screen.


Removed plug


Yada yada


39C, I was off by 1 degree! So I had to legit wait until it warmed up ... smh


Once at 40C, I hit OK to proceed


"does the oil flow out in small qty" = YES


From here, it counts down from 500 (it does count down rather fast)


Plug the fill port, tidy up, and all finished!


THE END

[willywi]

Did you notice any difference after the fluid change?

[383vett]

Thanks. Nice write up. With most auto transmissions, when the motor is off, the fluid level rises quite a bit because some of the fluid in the converter drains out. Try that on any car with a dipstick. You might want to recheck your oil level with the motor running.

[FranzX3M]

There is a rubber grommet that enters the transmission for the wires that should be replaced as well as it is known to leak after time. Maybe first change your ok with out but definitely replace after 2nd change ~ 120k miles. Per my mechanic who replaced mine on last change.

[AlexF25]

Thanks for the write up. Getting ready to do the trans. fluid/filter on my '11 28i so should be same procedure. Nice tip on taping the paper for the torque sequence. Also appreciate the extra info on following the procedure using the Foxwell tool.

What model Foxwell tool is that? Im in need of a proper scanner/tool to do service/code resets since i'm not having success getting ISTA+.

[evilchargerfan]

Originally Posted by willywi

Did you notice any difference after the fluid change?

per my butt dyno, the shifts do appear to be smoother and faster. it didnt make things worse... lol

Originally Posted by 383vett

Thanks. Nice write up. With most auto transmissions, when the motor is off, the fluid level rises quite a bit because some of the fluid in the converter drains out. Try that on any car with a dipstick. You might want to recheck your oil level with the motor running.

glad you enjoyed it!

well, you've convinced me. I will be going under the car, fluid at temp, engine on, and see how much more fluid I can fill. will report back soon ish

Originally Posted by FranzX3M

There is a rubber grommet that enters the transmission for the wires that should be replaced as well as it is known to leak after time. Maybe first change your ok with out but definitely replace after 2nd change ~ 120k miles. Per my mechanic who replaced mine on last change.

any idea what the PN is for that grommet? I'll def keep that in mind and have the part ready for the next one

Originally Posted by AlexF25

Thanks for the write up. Getting ready to do the trans. fluid/filter on my '11 28i so should be same procedure. Nice tip on taping the paper for the torque sequence. Also appreciate the extra info on following the procedure using the Foxwell tool.

What model Foxwell tool is that? Im in need of a proper scanner/tool to do service/code resets since i'm not having success getting ISTA+.

glad you enjoyed it Alex!

I have a NT530 model (scored off ebay for a cool $100). I believe the NT510 Elite is the exact same, but less pretty looking... and is less expensive. GL!

[isuzudave]

I am doing this job today. 383vett mentioned it already, but you are likely low on fluid.

With the engine not running the proper transmission oil level will be above the fill plug. I would suspect that's the reason you lost what looks to be about a quart of fluid when you removed the fill plug before removing the drain. I just barely loosen the fill plug before removing the drain plug (just to make sure it turns and I have the correct tool). I once removed the drain plug and later realized I did not have the correct tool to remove the fill plug. That was a long bicycle ride to the store.

[6MT_Addict]

Originally Posted by 383vett

Thanks. Nice write up. With most auto transmissions, when the motor is off, the fluid level rises quite a bit because some of the fluid in the converter drains out. Try that on any car with a dipstick. You might want to recheck your oil level with the motor running.

Procedure is intended to be run while the engine is on. If you fill it with the engine off it will not be full as you mention. Engine is on, and transmission at the prescribed temp.

https://f10.5post.com/forums/attachm...8;d=1526310564

https://aftermarket.zf.com/remotemed...p-50130-en.pdf

[evilchargerfan]

edited my #11 post to highlight (in bold) that I acknowledge what 383vett said and will try again with engine on

[pungo]

Originally Posted by evilchargerfan

edited my #11 post to highlight (in bold) that I acknowledge what 383vett said and will try again with engine on

I've never seen an automatic transmission where you didn't check the fluid level with the engine running at temp. It's been like that for many many decades, even the ZF pdf you attached says to check with the engine running at idle. Top that sucker up

[evilchargerfan]

Originally Posted by 383vett

You might want to recheck your oil level with the motor running.

Originally Posted by isuzudave

383vett mentioned it already, but you are likely low on fluid.

Originally Posted by 6MT_Addict

If you fill it with the engine off it will not be full as you mention.

Originally Posted by pungo

Top that sucker up

Today, I learned a valuable lesson. Dont skip steps!

• I turned on the engine, and this time kept it running
• I opened up the fill port
• I wanted until temps hit 30c
• I filled about 1L worth of fluid (YIKES, I was low indeed)
• I waited until temps hit 40c
• I filled some more fluid, roughly half of 1L
• Once a little fluid started to overflow out, I stopped filling
• I gave it a few moments to drain, then tighten the plug snug
• I turned off the engine
• I torque'd down the plug to 35nm

Thank you for those who kept me honest and made me recheck my work.

And thank you covid19 (work from home) from preventing me from driving around too much with low fluids

[383vett]

Originally Posted by evilchargerfan

Today, I learned a valuable lesson. Dont skip steps!

• I turned on the engine, and this time kept it running
• I opened up the fill port
• I wanted until temps hit 30c
• I filled about 1L worth of fluid (YIKES, I was low indeed)
• I waited until temps hit 40c
• I filled some more fluid, roughly half of 1L
• Once a little fluid started to overflow out, I stopped filling
• I gave it a few moments to drain, then tighten the plug snug
• I turned off the engine
• I torque'd down the plug to 35nm

Thank you for those who kept me honest and made me recheck my work.

And thank you covid19 (work from home) from preventing me from driving around too much with low fluids

We've got your back!

[walthoe]

Where is everybody reading the trans temp from?

[6MT_Addict]

Originally Posted by walthoe

Where is everybody reading the trans temp from?

You need go plug in a reader or computer with software like ISTA.

[evilchargerfan]

Originally Posted by walthoe

Where is everybody reading the trans temp from?

I've even heard of 1 guy using a meat probe


(I dont recommend this)

[6MT_Addict]

Originally Posted by evilchargerfan

I've even heard of 1 guy using a meat probe


(I dont recommend this)

I second this. Presumably the ZF read outs are specific to the area where the temp sensor is located in the trans. Pulling read outs with a laser thermometer, meat thermometer, or other external thermometer would give readings that are lower than in the trans since it's still heating up.

[pcarnut1]

Great write-up, thanks, will save this page for future reference. l like the graduated oil drain pan, where did you find that?