[JuniorB]

The n54 trans are slightly off auto or manual. You have to oblong the two holes that don't line up, it's the two top right bolts if I remember. Some insite on the m3 driveshaft, as I believe the m5 and m3 share a lot of its strength charasticts, like the output,imput, and outer shaft diameters. The output shaft for the n54 is smaller than the for the m3, same goes for the differences on the 335. Because the shafts are different between the two, you have to piece them from one to another. If he was to do a 335 rear swap, it would be bolt in. Im sure other can chime in on this.

[John@BPC]

Originally Posted by approximate

@John@BPC: can you please answer these two questions?

The transmission is using a factory OEM N54 bracket, and two holes were elongated in the transmission. One addtional hole does NOT line up whatsoever and this bolt was omitted.

as far as the input flange on the differential being switched, I cannot verify that these two are identical. The M3 differential looks much beefier and I would not imagine them having the same sized pinion.

[Terraphantm]

Originally Posted by John@BPC

The transmission is using a factory OEM N54 bracket, and two holes were elongated in the transmission. One addtional hole does NOT line up whatsoever and this bolt was omitted.

as far as the input flange on the differential being switched, I cannot verify that these two are identical. The M3 differential looks much beefier and I would not imagine them having the same sized pinion.

Again, I wasn't referring to the differential. The output flange on the transmission should be swappable and allow you to just use the M3 driveshaft if you're using the M3 subframe and diff too. Not that big of a deal, but strikes me as something that would be cheaper and easier than getting a custom driveshaft.

[rothwem]

Originally Posted by Terraphantm

Again, I wasn't referring to the differential. The output flange on the transmission should be swappable and allow you to just use the M3 driveshaft if you're using the M3 subframe and diff too. Not that big of a deal, but strikes me as something that would be cheaper and easier than getting a custom driveshaft.

I decided to peruse RealOEM, it looks like the E90 m3 trans is a GS6-53BZ, while the 335i is a GS6-45BZ. They're totally different looking transmissions.

Edit: it looks like the 335i that I was looking at is an newer build, and probably an n55. The older 335i with an n54 seems to use the 53bz. They look different though.

[John@BPC]

Precisely, they flanges are NOT compatible.

[Terraphantm]

Originally Posted by rothwem

I decided to peruse RealOEM, it looks like the E90 m3 trans is a GS6-53BZ, while the 335i is a GS6-45BZ. They're totally different looking transmissions.

Edit: it looks like the 335i that I was looking at is an newer build, and probably an n55. The older 335i with an n54 seems to use the 53bz. They look different though.

Originally Posted by John@BPC

Precisely, they flanges are NOT compatible.

I still think a 53 to 53 output flanges should work, but I can't find a good picture of an unmounted N54 output flange to compare with the M3 one, so whatever. No point arguing over a minor curiosity

Edit: I did find an E60 N54 guy who swapped to the full M5 rear end and installed the M5 output flange (which is the same part number as the M3 one). So it seems like it does fit. http://www.m5board.com/vbulletin/e60...ml#post6791081 Though I see later in the thread he had his driveshaft lengthened anyway, so I guess it's pointless. Guess the M3 engine + transmission sits a bit farther back.

[Blau]

Originally Posted by John@BPC

The transmission is using a factory OEM N54 bracket, and two holes were elongated in the transmission. One addtional hole does NOT line up whatsoever and this bolt was omitted.

as far as the input flange on the differential being switched, I cannot verify that these two are identical. The M3 differential looks much beefier and I would not imagine them having the same sized pinion.

Did you have to do any further modification to get the shifter to like up?

And which flywheel/ clutch did you use? The one for the n52 or n54?

Thx