I posted here a few weeks back talking about how loud the motor bearings had gotten in my 2015 BEV (81000 miles), I decided it was finally time to fix it. I’ve put a short audio clip on YouTube of how bad it sounded, this was recorded with the boot covers off and the seats down. Believe me, it doesn’t do it justice just how bad it sounded! [https://youtu.be/XVVhhKdqcPc](https://youtu.be/XVVhhKdqcPc)

I purchased a motor and gearbox out of a low mileage 2019 I3S £450, then spent another £500 or so on other parts (new motor mounts, gearbox oil, coolant, a few new bolts, new top mounts etc). I also spent a couple of hundred on some new tools, mainly a high powered impact wrench that could easily defeat hub nuts and any tight suspension bolts, and a motorbike jack which I used to lower the motor.

It took me about a week, mostly working in evenings (around the rain!) with one long day at the weekend where a friend helped me with dropping the motor out. You probably could do it on your own, but it was safer with a 2^(nd) pair of hands. If I did it again, I could probably do it a lot quicker, but I wanted to take my time with it and make sure I did everything correctly as I’ve not attempted a job on a car this big before.

I mainly followed the Instructions from ISTA, but also used this really helpful you tube video as a reference (it’s for a REX, which makes the BEV seems a piece of cake!) [BMW i3 Motor Replacement: I Had To Completely Disassemble The Rear End!](https://www.youtube.com/watch?v=zVXWpaT9ULw)

I’m not sure if I can share the ISTA instructions here, but you will need ISTA to program the motor ID, and possibly calibrate the parking module on the gearbox anyway.

I used a motor bike jack to lower the motor, I lifted it flush under neath the flat bit at the right of the motor, then cut a few blocks of wood to sit on the mounts the BMW recommend using. I also used a ratchet strap as a 2^(nd) precaution, but It was fairly stable.(Pic 4-5)

The only thing I had to improvise a bit on was unplugging the HV cable from the A/C compressor, no idea how you are supposed to do that without an extra joint in your arm! In the end we used the jack to hold the weight of the motor, undid the right and centre mounts, then removed the right-hand large metal support bracket completely. When we then removed the left mount, it gave us enough space to slightly lower and twist the motor enough I could get my arm in to disconnect it.

Aside from that it was time consuming, but fairly straight forward. I found that both my motor mounts were split and completely broken, and the old plastic support arm was badly cracked. 

I also did the front top mounts while it was in the air, they were absolutely trashed, the drivers side one fell apart as I removed it!

Now it’s all done it’s like a different car, almost silent and drives much nicer with the new mounts.

 

I Thought I would share my experience on here in case it encourages anyone else to have a go, DIYing it saved me thousands. (Obviously with the usual disclaimer about closely following all the warnings on working with the high voltage systems)

I Just completed a DIY Motor/Gearbox replacement (BEV)