Why do you want to swap the differential? Do you want to increase acceleration? Secondly, I’m not sure that a differential from a 325 will properly fit you car as we didn’t get that model.
Go to www.realoem.com and enter the last 7 characters of the car’s vehicle identification number. Hit enter and bookmark the page. Scroll down to rear axle. Click on the part numbers for the half shafts and other parts to see if there were used in the 325. Also check the driveshaft section. It seems bmw used different driveshafts for different cars.

 

Why do you want to swap the differential? Do you want to increase acceleration? Secondly, I’m not sure that a differential from a 325 will properly fit you car as we didn’t get that model.
Go to www.realoem.com and enter the last 7 characters of the car’s vehicle identification number. Hit enter and bookmark the page. Scroll down to rear axle. Click on the part numbers for the half shafts and other parts to see if there were used in the 325. Also check the driveshaft section. It seems bmw used different driveshafts for different cars.

Okay i appreciate your advice...thanks and yeah mainly to increase acceleration

 

BMW Gear Ratios - E36 / E46 / E90 / E91 / E92 / E93 / E85 / E86 / E83 / E82 / E88

output flanges of old differential could be swapped to the new one, so no need for other axles. Driveshaft on differential side is the same on all E46's with the exception of the 330i.

 

When replacing the output flanges, should they have any play in and out? or does that mean the circlip or it's groove is worn?

 

what year is your 320i?
I’m pretty sure your automatic uses a 3.38 now. so a 325i automatic 3.46 is a slight bit better but it’s going to barely be noticeable.
now if you have to replace your current one because it needs it then yes it’s a simple upgrade. but to do it just for an upgrade it’s hard to say if the cost and labor is “worth” it to you.
but yes it will give a slight bit more pull raising your current rpm 2% from where you are now.

if you’re looking for a bigger project and gain you could look into finding a 3.64 or 3.91. not sure what’s involved on a 320i to retrofit but it’ll be a bigger project.

 

A better power upgrade is a M54B30 engine swap. Increases power from 126 kw (170 hp) to 170 kW (228 hp) and is plug and play.
mega_stihl can probably point out any differences between that and your M54B22.

 

I better power upgrade is a M54B30 engine swap. Increases power from 126 kw (170 hp) to 170 kW (228 hp) and is plug and play.
mega_stihl can probably point out any differences between that and your M54B22.

Still haven't checked the diff. Sorry for that. To answer the above:

My B30 still isn't 100%. Need a decent tune, and I have a vacuum leak (my own fault). But what I can tell you so far: at first, it doesn't seem like that big of a difference, but once you surpass the 4000 rpm, it's a fucking beast compared to the B22.

It is plug & play. Engine is a direct fit, and the wiring needs minor to no adjustment. All you need is a new map/flashed ECU, because it will not run like it's supposed to with the B22 mapping.

I still have the 3.38 differential, which pulls really nice, but I'm gonna put in a 3.07 soon, because I don't like making that much rpm at highway speeds. A 6-speed would be nice, but is really pricey here.

 

Whoa whoa whoa..
guy comes in asking about a 2-3 hr $100 diff swap and you guys come back with a M54 3.0L complete engine swap?? 🤣

 

I just felt important for a moment because someone mentioned my name. Thanks for ruining it for me 😢

 

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