ActiveE Technical Issues(part 1): Splines, Splines Everywhere There's Splines!

The teeth (splines) of this ActiveE gear have been grinded away

What the hell's a spline you ask? Don't feel bad I didn't know what it was either and I'm a fairly "technically competent" guy. So when an ActiveE Electronaut posted in our Facebook group a month ago that he needs a new motor because he had 'spline failure' I had to look it up. Turns out splines are just the technical term for the teeth of both the male and female ends of a gear. Spline: A flexible connection featuring grooves cut in a shaft that mate with corresponding grooves in a connecting member, such as a hub.

Suddenly everybody in the group was buzzing about splines like it was some advanced technology that BMW somehow under-engineered. It's just a simple gear, nothing complicated about it. Question is why are they failing on so many cars, and on a personal level why hasn't mine failed? I have way more miles than anyone else who has an ActiveE, I'm close to 21,000 miles now and the next person (that I know of) is around 13,000. Plus, many of the gears are failing on cars with less than 5,000 miles! Why would that be?

Possible Causes: (my opinion only)

Abusive driving. Maybe the people that have had the gear failure are just really punishing the car beyond its capabilities. There were a few MINI-E drivers who were known to have really abused their cars which is why BMW tightened up the rules and return policies on the ActiveE, making us more accountable for the condition the car is in when we return it. Probability: 5%

Bad batch of gears. It could be that BMW simply got a bad batch of gears that were defective metal. Probability: 15%

The car is too heavy. The drive system for the ActiveE wasn't designed for the ActiveE. It was designed for the 2013 BMW i3 which will be about 1,300lbs lighter than the ActiveE. Could it be the gear just can't handle the stress of applying 184lb-ft of torque to move a car that is over 4,000lbs before you add the weight of the passengers? Probability: 20%

Improper lubrication from factory. All of the pictures of the gears that ActiveE drivers have received from their service departments show the gears devoid of any grease. Gears like this obviously need an ample amount of lubrication or they will grind themselves away in short order. Did the factory just forget to grease some of the gears? Probability: 25%

Lubrication leak/washed away. Perhaps the factory did properly lubricate the gears, but there is either a design flaw that allows moisture to seep in and wash the grease away or there is some kind of faulty seal that allowed moisture in on some cars and that's why their gears failed and others didn't. Probability: 35%

Rusted & Stripped

Then maybe it's a combination of a couple of these possible causes. Maybe the gear is stressed to its limit because of the extra weight, there's an issue with moisture getting in there somehow and the ActiveE drivers love the feel of the instant torque so much they punch the accelerator every chance they get. Or maybe I'm missing it completely. If you think you have a better cause, please feel free to post your thoughts in the comments section. Of course if a BMW technician who knows the real reason(s) wants to post there also anonymously, I won't mind that either. ;)

Technical issues are expected with the ActiveE. This is a car that is purely a test vehicle, meant to fully vet the components that will be used in the 2013 BMW i3. BMW also gets the CARB credits they need, which personally I'm fine with, and they have never disputed that the ZEV credits are part of the reason they did the MINI-E and ActiveE programs. However as long as these programs allow people like me to drive electric, and help BMW improve the technology so the cars they begin selling next year are the best they can be, then I think they are more than worth while. Just about everything in the ActiveE is new. The motor, the power electronics, the KLE(onboard charger), the battery modules, the active thermal management system and the entire high voltage battery system have never before been used an any vehicle so it would be foolish to think there wouldn't be technical issues like this. I've been a big supporter of the BMW electric vehicle program and sometimes when I take a step back and look at my posts I think I may be too positive without showing all of the challenges we in the program face from time to time. That's why I've decided to add a new series of posts called "ActiveE Technical Issues" that I will mix in with my other posts, highlighting the problems the car (and the people driving them) face.

This by no means is an indication that I don't love the car and regret applying for the program, which I don't for a minute. The ActiveE is really a great electric car and just about everyone I know who has one feels the same way. But it is a test car, and the technical deficiencies as compared to a production car do come out from time to time, and I'm going to do my best to write about them, just as I do for all the great qualities the car has.