In agreeance with Stephen, do not attempt this repair on the 820 unless you have a seperate custom made impeller. The 800’s will not work and after grinding it down with a dremel, it still jammed. Breville will not send you the part which frustrates me even further.
I’m going to work on a 3D printed one soon, but for the time being, don’t bother. Go buy a Sette.
Just did this a week ago Ben… there is no way to fix the 820 unless you get a custom 3D printed impeller for the 820. The 800 one does not fit. The finer the grind, the more likely it is to jam. While the impeller is in a stainless steel sheathe, it’s just plastic underneath and it does wear out especially if you are using it for espresso. I have just purposed that grinder for pour over only.
I bought a Sette 270 to replace it as well. No clumping, great control, and low grind retention.
Check your model here. Breville has upgraded the grinder to the BCG820XL which uses a different assembly up top. Getting this part off is tricky, but I have been able to do it.
1. Take the two screws off the small white gear which will allow you to lift the white gear out of the way - this is how the digital readout measures the grinder. Do not touch this, else you will mess up the grind readout.
2. Remove the two screws in the large black plastic gear.
3. While holding the inner smooth plastic ring in the center of the large gear, turn the grind control knob until this piece of plastic lifts out.
4. Pull out bad impeller and replace. The shapeways BCG800XL model does not fit and I have been unable to locate another one. Going to work on printing a new one in my free time.
5. Work backwards to put back together.