Should also add that my cars manual and the 02 330 is auto

 

See if realoem has different part numbers for the abs and wheel speed sensors. The pad sensors are different for sure

 

According to realoem they appear to be the same. My curiosity comes from the band on the axle that the sensors use to read speed. With the axles changing I was worried that 325 sensors would read the 330 band incorrectly.

My question is why change the rear brakes. The rears do about 35% of the braking and the increased swept area isn***8217;t that large.

It's nice to keep the brake bias atleast somewhat close to normal(330 MC would be needed for perfect bias). Also I have all the suspension out of the car for a refresh so this is as good of a time as ever to change the RTA/hubs to 330. I know the rears arent going to have a massive effect but since I dont have to go too far out of my way I figured why not.

https://forum.e46fanatics.com/showthread.php?t=686940&page=2

in case the pics don't show, see below on my own hosting:
http://www.argyrides.eu/bmw/mods/330_rear_brake/rear_brakes.htm

Thanks, I saw your thread earlier but since I already have everything out of the car going through with the 330 conversion is actually the easier option for me at this point

 

My question is why change the rear brakes. The rears do about 35% of the braking and the increased swept area isn’t that large.

 

I would also add that this brake conversion is a waste of time, effort, and money. The 330 has bigger brakes for the edge case where they’re being pushed a lot harder than a 325. You won’t see any difference in stopping distance as that’s mainly governed by the tires. BBKs are for handling a higher heat load more than anything.

 

https://forum.e46fanatics.com/showthread.php?t=686940&page=2

in case the pics don't show, see below on my own hosting:
http://www.argyrides.eu/bmw/mods/330_rear_brake/rear_brakes.htm

 

Ignoring the 'why', there are 2 types of ABS sensor, and the Bentley says that after a certain date, they change.

So take a look at the Bentley, and make sure that your car and your donor are the same side of the change date, and you should be good.

what I read in a book somewhere,
t
also pointlessly upgrades brakes for obscure reasons like 'now I only have to stock one set of spare calipers for 3 cars...'

 

I know this thread is a couple weeks old, but for posterity, here's the poop. 330 brakes are cool and everyone should swap to them. Note that this info is specific to RWD models. I have never owned an AWD E46, so I have no idea what their situation looks like.

Trailing Arms:
If it's from a 330, it's fine. I think the part numbers changed over time, but the important stuff stayed the same. Source: my 325 has trailing arms and axles from a suuper early build 330.

Axles:
For the most part, the 330 used a 34mm diameter axle on autos and a 38mm diameter axle on manuals. The very early manuals also used the 34mm axle. The 34mm axle use the same diff output flange as the 323/325/328, so it'll bolt on to those diffs. The 38mm axle uses a different/larger bolt pattern on the output flange, so you'll have to swap the flanges as well if you want to use those axles.

Also important to note that the axles didn't change over time, at least with regard to the tone rings. My MK60 325i has axles from a MK20 330i on the rear, and they interface just fine with my factory ABS sensors.

ABS Sensors:
There's basically two "generations" of sensors, and two "styles" of sensors with regard to the rear. If you know your "generation," the differentiator is basically whether or not you are using the 38mm (330 manual) diameter axles. The 38mm axles use a sensor that sticks further into the trailing arm to properly read the tone ring on that specific axle.

MK20 DSC cars (built pre-mid-01, not sure of actual cutoff) used the gray-connector "generation" of sensors.
"short" - 34521164370 - 323, 325, 328, 330 (auto trans/very early build manual trans), M3
"long" - 34521166126 - 330 (manual trans)

MK60 DSC cars (later build, like the OP's 2005) used the blue-connector "generation" of sensors.
"short" - 34526752683 - 325, 330 (auto trans), M3
"long" - 34526752702 - 330 (manual trans)

_______________________________

So, to sum up, here's the two questions you need to answer to get the correct sensor for your RWD E46:
What color connector is on my factory sensor? - gray (MK20) or blue (MK60)?
Which 330 axle am I installing on my car? - 38mm (manual) or 34mm (auto)?

If I'm wrong, feel free to correct me. If you're actually doing the swap, make sure you verify this info before you make any purchases, because I'm just some dude on the internet. Pretty confident this info is correct, though.