DIY Disclaimer: I hold no responsibility should anything goes wrong when you decided to follow my guide. It’s strictly meant as a reference for knowledge sharing purposes.
2007 BMW E90 N46B20
Mileage: 80k km
Transmission model: ZF GA 6HP19
1. Park the car on a level ground. Secure the rear wheel from rolling. I use a piece of brick.
2. Jack up front left of the car. I use my Toyota scissor jack. A hydraulic jack would make the job a lot more easier.
3. Place extra support to prevent the jack slip. I use another brick below the raised front left tyre and a jack stand to support the lower arm knuckle end.. I also inserted a piece of solid rubber into the plastic jack stand point to prevent the plastic jack stand point from damage due to the incompatible jack used.
4. Open the bottom shield (item 10) and ..
.. unscrew fill bolt (Item 3)
Get the drain pan ready because old ATF may gush out when the fill bolt is removed, best just loosen it first and leave the bolt in place until step 5 below is completed.
5. Release drain plug (item 4) and the used ATF will be released.
6. Close the drain plug (item 4 above), don’t over tighten because it’s plastic, can break.. and they don’t sell them separately. It comes with a new plastic transmission oil sump.
7. Insert refill hose to feed new ATF. Do not push in too much as you can damage the transmission box’s internal fragile components.
8. Drop the jack so the car is level to the ground again. Refilling ATF must be done with car level to the ground.
9. Pump in ATF until overflow and that’s how they measure the level.
10. Start the engine with aircond running, and run through all the gears R, N, D, DS, M1~M6, 3 seconds for each with handbrake engaged and brake pedal firmly depressed. Then back to ‘P’ and let engine run for 3 minutes to heat up the ATF to 30~35 Celsius.
11. With the engine running, top up the fluid until it overflow. Make sure it’s not exceeding 50C because you will under-fill the fluid due to heat expansion.
12. Jack up the car again to plug the fill bolt and reinstall lower shield.
Some photos to help you better understand the procedure.
~ Getting ready the fill hose.
~ Check out the other end of the clear refill hose, getting ready to be inserted into the fill hole.
~ The tools that helped me open the fill bolt and drain plug.
~ Below is how the "custom” tool being used to open the plastic drain plug. I do not the a hex wrench that’s large enough, has to DIY the opening tool..
~ Work in progress..
~ Fluid used, the red cap is old stock, blue cap is new design. Old bottle design do not have an inner plug while the new design has. 4L is sufficient if transmission sump with embedded strainer is not replaced.
~ Fluid level guide.. http://www.scribd.com/doc/97008578/6hp19-21-Bmw-Fluidlevel
After the job, I found few better ways to perform the job. Please stay tuned!
Thank you for reading and please provide feedback or query if any.
Next job should be valve cover gasket..
Update: Found ZF Procedure in Video: https://www.youtube.com/watch?v=ZRrgmfM8VlQ