BEV E-Motor transmission/differential Oil - change?

[OyaNET]

Just changed my gearbox oil today while doing the motor mounts.
My 2014 BEV got 96kkm on it, so about 60kmiles. The oil I've drained was about 0.5liters, looked filthy, and there was a spectacular formation of magnetic "paste" of gear pixie powder on the drain plug magnet. The good news was however it had no solid chips or shavings in it, just the finely ground metallic powder.
I've gone the easy way, and refilled with 0.5L of 75w80 BMW GL4 oil through the vent hole. It was a very easy affair.

 

[Arm]

FYI...

This is the latest video I've found on this subject...good one.

https://www.youtube.com/watch?v=7zL04N_py0E&t=624s&ab_channel=GrayWing

These are the list of items used: @4:02

https://youtu.be/7zL04N_py0E?t=242

BTW...for anyone who's done it...did you see any noticeable difference after the oil change?

 

[Arm]

Bumping this thread for updates. Thanks!

- Is the Liqui Moly a superior oil to the OEM oil?
- has anyone seen a noticeable change after changing the oil?

Thanks!

 

[Timjohn]

OK how do you perform this procedure with a REX? I would think the breather would not be very accessible. What is the dimensions of the drain plug ...M12 x 1.5 or? My 2020 i3S with REX has no filler plug and I have seen a YouTube video where he changes the fluid uses the drain plug orifice only. Tricky.

 

[nilknarf]

M16x1.5. There's another thread about doing the rex. It's titled "Transmission oil change on a Rex from 2016 onwards".

If you have a later model Rex, the only fill options are though the drain plug or removing the axle.

 

[Timjohn]

What is the size of the drain plug? M22 x 1.5 or M16 x 1.5. I have conflicting information. The 2014 to 2018 models years have a fill plug and then BMW removed the fill plug in later years. But I think my 2020 i3 has the smaller M16 x 1.5.

 

[nilknarf]

2017 and 2018 rex's do not have fill plugs.

 

[Timjohn]

This is my setup for my tranny oil change. M16 x 1.5 to 1/8 NPT with a 3 ft length of silicone tubing #18.

2020 BMW i3S

 

[Paul Quixote]

Just changed my gearbox oil today while doing the motor mounts.
My 2014 BEV got 96kkm on it, so about 60kmiles. The oil I've drained was about 0.5liters, looked filthy, and there was a spectacular formation of magnetic "paste" of gear pixie powder on the drain plug magnet. The good news was however it had no solid chips or shavings in it, just the finely ground metallic powder.
I've gone the easy way, and refilled with 0.5L of 75w80 BMW GL4 oil through the vent hole. It was a very easy affair.

Thanks for sharing. Since you have a 2014, didn't your gearbox have a fill hole? Or was it just easier to use the vent hole to add the new oil. Also, how hard was it to change out the motor mounts? Did that require any special tools?

 

[airman2482]

Thanks for sharing. Since you have a 2014, didn't your gearbox have a fill hole? Or was it just easier to use the vent hole to add the new oil. Also, how hard was it to change out the motor mounts? Did that require any special tools?

Just changed my gearbox fluid. Used the vent hole in my 2017 i3-REX. 500mL. GL5 standard. Didn’t use BMW oil.

The local dealer does recommend changing the gearbox fluid at 50,000 miles.

When asked - the BMW shop manager/foreman responded with - “Liqui Moly makes good stuff. Through ETK BMW fluid has part number 83 22 2 413 512 and it is labeled as BMW G3 GL5 70w/80 - if the Liqui Moly is the same it should be fine.”

I used Liqui Moly 75w90 gear oil as a couple of other friends have.

The BMW shop manager amateur races BMW cars in the local club area. He’s got nearly 20 years experience with Beemers and now 10 with Beemer EV’s. The service manager is a former NHRA racer and a dragster driver. Lots of experience at this BMW shop!

Good luck!

 

[nilknarf]

airman2482, you are the first person that I've heard about being able to reach the vent hole on the 2017 rex. This is a revelation as everyone that I'm aware of with a later model rex has been having to fill through the drain plug hole. Can you please provide some details on what you had to remove in order to reach the vent?

 

[Redryder18]

Back in the day, if you stripped off an oil pan drain plug and it was empty then you could do your job and put a new one or a bigger one. But if you’ve already done the oil change and you go to tighten it strips, but I’ve seen done on a full oil change job is to open the filler cap and have someone hold a shop vac very very close to the filler so there’s airflow through the drain plug bubbling through the oil keeping the oil from draining out.

 

[airman2482]

airman2482, you are the first person that I've heard about being able to reach the vent hole on the 2017 rex. This is a revelation as everyone that I'm aware of with a later model rex has been having to fill through the drain plug hole. Can you please provide some details on what you had to remove in order to reach the vent?

I watched a YouTube video on using the vent hole. The earlier models supposedly had a fill plug. The guy on YouTube was quite informative! He lists all parts he needed.

I’m going to replace the spark plugs on the REX motor next. There is also an very informative video on YouTube on this too!

Good luck!

 

[Chrism88]

I watched a YouTube video on using the vent hole. The earlier models supposedly had a fill plug. The guy on YouTube was quite informative! He lists all parts he needed.

I’m going to replace the spark plugs on the REX motor next. There is also an very informative video on YouTube on this too!

Good luck!

How did you reach the vent hole? Isn’t it sandwiched between the motor and your inverter quite a long ways down?

 

[tob1as]

I watched a YouTube video on using the vent hole. The earlier models supposedly had a fill plug. The guy on YouTube was quite informative! He lists all parts he needed.

I’m going to replace the spark plugs on the REX motor next. There is also an very informative video on YouTube on this too!

Good luck!

Could you share a link to the YouTube video, please? (The gearbox fluid one)

 

[airman2482]

Could you share a link to the YouTube video, please? (The gearbox fluid one)

I’ll dig it up. It’s on a YouTube watched video list.

 

[nilknarf]

I'd love to see this video as well. I searched youtube for ~15 minutes and couldn't find it. airman, when you indicated "vent hole" you were referring to the tube on the top of the gearbox and not the opening that houses the drain plug, correct?

 

[lopezjm2001]

I did mine by filling through the vent hole. After 6 years and 120k km.

 

[airman2482]

I'd love to see this video as well. I searched youtube for ~15 minutes and couldn't find it. airman, when you indicated "vent hole" you were referring to the tube on the top of the gearbox and not the opening that houses the drain plug, correct?

I'd love to see this video as well. I searched youtube for ~15 minutes and couldn't find it. airman, when you indicated "vent hole" you were referring to the tube on the top of the gearbox and not the opening that houses the drain plug, correct?

Sorry, I should have been more clear.

I replaced the gearbox fluid when I replaced spark plugs on my REX. There’s a hose on the top left side of the REX one has to remove to get better access to the vent hole. I would be careful removing the top of the REX when replacing the REX sparkplugs. There are a couple electrical connectors that break real
easy. (Crappy plastic connectors).

It’s isn’t hard to do, just take time and go slow. Make sure you photograph every step of the way for easy reference to put the thing back together.

I suppose one could use a suction device through the fill hole to suck up all the fluid and replace it. I don’t know, didn’t do it this way.

Sure glad I replaced the spark plugs, they were pretty “burned” and “wide gapped”.

Good luck! Be careful!

 

[Mr. Bad Mechanic]

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