New transmission required

After 72000 miles and 1 month before expiration of 3 year warranty noticed my June 2017 Rex had developed a rattle from the rear end. It didn’t sound to serious but nevertheless managed to get it looked at by the local dealer and discovered the transmission had failed and it needed a new transmission!! Cost to me zero but a month later would have been approx £6000 GBP.
I feel blessed I had warranty but rather worried that less than 3 years in something so costly could go wrong.
Now searching for best extended warranty deals for when warranty expires!!

I just got a 2017 REx myself, and, reading posts like this, I'm very glad that I bought it CPO and got another year extended warranty so I'm covered until late in 2023. I hope I don't need to use it the warranty, but puts my mind at ease knowing I have it.

It's really weird that the single-speed transmission died, and even weirder that it would cost so much to replace. Again, this is a single-speed transmission. It doesn't even have to shift gears! Shouldn't this car have the CHEAPEST transmission imaginable?

Do you have a breakdown of how much of the repair cost would have been parts and how much labor?

Horror stories always get attention. But there are quite a few good reads about various aftermarket extended warranties that go wrong, too (multiple deductibles, non-covered repairs, general foot dragging).

I think you're right about the i3 transmission. There's not much to go wrong so this would seem to be an outlier. But more importantly, there are plenty of wrecked i3s out there to pick a drivetrain from, for much less the the quoted BMW price. Much better, in my humblest of opinions, to bank that money, knowing that the i3 is a generally reliable vehicle that probably won't need expensive repairs.

So with it being warranty I didn’t get an exact breakdown. They had it 2 weeks due to Covid 19 so don’t know how many hours labour but at £60 p/h maybe £5k parts and £1k labour. I did ask “so if the new transmission breaks again is there any period of warranty for that?” To which the answer was “no”.

MikeH said:

So with it being warranty I didn’t get an exact breakdown. They had it 2 weeks due to Covid 19 so don’t know how many hours labour but at £60 p/h maybe £5k parts and £1k labour. I did ask “so if the new transmission breaks again is there any period of warranty for that?” To which the answer was “no”.

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Something doesn't pass the smell test here. The i3 has a single speed reduction gear and a conventional differential. The multitude of gears, bands, clutches, torque converters and control hydraulics and electronics found in nearly every automatic transmission is not in the i3 with it's two gear wheels and no clutches, no bands, not torque converters, no hydraulics, and no electronics. The price for this simple gearset would be outrageous for most automatic transmissions, but perhaps expected for a conventional automatic tranny for a modern BMW or MB or Jaguar or such. It is insane for the i3.

I think a transmission failure in the i3 is very rare, I wonder if it was the transmission mounting bolts or the the transmission bracket that broke, that's much more common?

The transmission itself is less than $1k - £6000 GBP for installed one seems way overpriced.
https://www.realoem.com/bmw/enUS/partgrp?id=1Z43-USA-09-2014-I01-BMW_i-i3_60Ah_Rex&mg=27
https://www.thebmwminipartstore.com/oem-parts/bmw-gear-assembly-27208681526

This is the only instance I remember, in more than 5 years, of hearing of a failed transmission - seems pretty rare. And between new and used, and the replacement effort compared to an ICE car transmission, shouldn't be too hard to find a reasonably priced fix. Glad OP did not have to pay for it too.