[terryd5150]

Originally Posted by Ryanfknt

The problem was that the E90 tcase has the tcase resistor but my f30 trans harness did not have that. That was putting me in limp mode etc..

I took the tcase off my old trans and it bolted right onto the E90 trans. Same length, no problems. Check engine lights are gone, no more limp mode. Everything is good!!

I do still have “automatic start/stop malfunction” because of the zero neutral sensor on top of the trans.
This doesn’t effect driveability
Maybe I can find a way to code that out??

overall; MSSION SUCCESS 🍻

Ryanfknt

How did you overcome the shifter linkage issue?

[Ryanfknt]

Originally Posted by terryd5150

Ryanfknt

How did you overcome the shifter linkage issue?

Neither of the shift linkages will put your shifter in the center of the boot.
After extensive measurements and building a little jig I cut the linkage and the shifter bracket In half and added I think like 3/4” to both ( shift bracket is aluminum, linkage is steel) no photos, but I got the shifter to sit PERFECT in the center of the boot.

What I figured out, and what made it so important to get the shifter dead center in the boot, is that the shift throw is longer in the new trans.. the throw is MASSIVE using my original f30 shifter and on 1-2, 3-4, 5-6 shifts, the shifter almost hits the front and back of its allotted shifter space.. I also had to dremel the bottom of the shifter in a certain spot to allow it to throw that far..

ALSO The n54 shift bracket isn’t made for my f30 shifter, so I had to dremel cut and grind all sorts of weird spots to allow the shifter to navigate through the gears without hitting the bottom of the shifter/ linkage off the shift bracket..

So it was actually a lot of work and honestly the only hard part of the swap (now that we know the solution the tcase issue I had)

If your a decent fabricator you’ll figure out how to make this shifter setup work eventually just gotta put the hours in!

IMO I need to get a f30 short throw shifter with this new trans to be back to normal..

BUT the gears hold great, no synchro issues, and I beat on it pretty good now that the clutch is broken in and it is so great!! Great success I couldn’t be happier with it

[burl25]

Originally Posted by Ryanfknt

Neither of the shift linkages will put your shifter in the center of the boot.
After extensive measurements and building a little jig I cut the linkage and the shifter bracket In half and added I think like 3/4” to both ( shift bracket is aluminum, linkage is steel) no photos, but I got the shifter to sit PERFECT in the center of the boot.

What I figured out, and what made it so important to get the shifter dead center in the boot, is that the shift throw is longer in the new trans.. the throw is MASSIVE using my original f30 shifter and on 1-2, 3-4, 5-6 shifts, the shifter almost hits the front and back of its allotted shifter space.. I also had to dremel the bottom of the shifter in a certain spot to allow it to throw that far..

ALSO The n54 shift bracket isn’t made for my f30 shifter, so I had to dremel cut and grind all sorts of weird spots to allow the shifter to navigate through the gears without hitting the bottom of the shifter/ linkage off the shift bracket..

So it was actually a lot of work and honestly the only hard part of the swap (now that we know the solution the tcase issue I had)

If your a decent fabricator you’ll figure out how to make this shifter setup work eventually just gotta put the hours in!

IMO I need to get a f30 short throw shifter with this new trans to be back to normal..

BUT the gears hold great, no synchro issues, and I beat on it pretty good now that the clutch is broken in and it is so great!! Great success I couldn’t be happier with it

Hey man,

If you ever get around to updating anything with this project or the short throw shifter upgrade to fix the long throw it would be really appreciated.

Could you maybe describe what you had to dremel? I attached a pic of the two brackets side by side

Thanks man your documentation is really helpful

[FellowM3]

Any updates on this?

Running same issue. Have a 13' 335i, RWD 6-spd. Bad 1-2 and I want to know best way to fix this.

Def dont have the skills to do a full swap and fabricate/modify to make this work.

[n55david]

Originally Posted by FellowM3

Any updates on this?

Running same issue. Have a 13' 335i, RWD 6-spd. Bad 1-2 and I want to know best way to fix this.

Def dont have the skills to do a full swap and fabricate/modify to make this work.

Replace the trans.. its the only way to fix it

[F30RiK]

What about using a 2010-2011 e90 n55 transmission? They look almost the same and are way way cheaper. I have an issue with my second gear on my 2013 335 xdrive and im not sure what to do. Here in Canada the price of a refurbished transmission is 7000 with taxes.

[n55david]

Originally Posted by F30RiK

What about using a 2010-2011 e90 n55 transmission? They look almost the same and are way way cheaper. I have an issue with my second gear on my 2013 335 xdrive and im not sure what to do. Here in Canada the price of a refurbished transmission is 7000 with taxes.

They all have similar issues

[Polo08816]

Originally Posted by Ryanfknt

As we all know or as you will quickly find out, the transmission that is paired up with the n55 6mt is fragile. Or complete junk. Call it as you want. It fkn sucks. The synchros are made of glass and many people have needed to replace them (very expensive)

I drive a 2014 f30 335i xdrive. The second gear synchro is bad. After lots of research, I decided the stronger alternative is from the older cars equipped with the n54. I bought a complete trans, shift bracket, with front and rear driveshaft from a 2010 335i xdrive.

I’m just going to list some things for other people to use that have similar interest.

The n55 is equipped with the gs6-45bz
The n54 is equipped with the gs6-53bz


The two best posts that I found that convinced me to follow through with this.
https://www.1addicts.com/forums/show....php?t=1386237
https://www.1addicts.com/forums/show....php?t=1632598

The posts above say to swap in to the n54 shift bracket, and you need the n54 front and rear driveshaft to make up for the different length of the trans.
I now have my gs6-45bz removed and sitting next to the gs6-53bz that I bought:
measurements from the bell housing show both front and rear driveshaft are exactly the same distance from the bell housing on both transmisssions. So with the two transmissions I have, I don’t need to swap to different driveshafts.
Measured to the front edge of the bell housing, The center of the shifter with the n54 shift bracket actually sits 3/4” closer to the front of the vehicle. I haven’t finished install so I don’t know how much of a problem this will cause.

Things to know:
Have to extend one wiring harness (I believe it is a 2 prong harness)
gs6-45bz pilot bearing in the flywheel
gs6-53bz pilot bearing on the trans (Input shaft on the flywheel)
My solution: Spec 2+ Clutch with steel SMFW for 2010 335i (comes with input shaft on the flywheel)

The only thing that makes the xdrive more difficult is the distance to reach “the bitch clip” on top of the tranny. My clips were seized on there so I just cut the shift bracket off because I am using the bracket from the n54. But HOLY SH$T this tranny is EASY work. The top two bolts on the bell housing I could get right through the top without any assistance, just lots of extensions. I don’t know why anybody would need to fish through under the hood while having assistance underneath. It is a clear path to EVERY SINGLE bell housing bolts once you drop down the tranny mount. Like seriously this was way easier than I expected. It’s actually fun how easy this trans was to remove.

I’m still in the middle of the swap, I don’t really have any questions, and I and a total noob. I just wanted to post all the information I could on it because it has been so damn hard to find anything at all diy on the f30 n55.

One thing I can’t find is how to do the rear main seal. That’s where I am right now on google.. and I am interested in seeing how the shift bracket will work out with it being 3/4” forward. I will be sure to keep this post updated!!

I wouldn't consider someone who is undertaking a transmission replacement/swap a noob. Let alone a retrofit of a transmission designed for another chassis.

[SpoolinAddict]

Originally Posted by n55david

They all have similar issues

Does the N55 E9X MT cars suffer the same issues? In the future I wanted to get a higher mileage n55 e90 MT but I keep seeing there's no parts available and you would have to do a full swap of a new or used transmission.

[n55david]

Originally Posted by SpoolinAddict

Does the N55 E9X MT cars suffer the same issues? In the future I wanted to get a higher mileage n55 e90 MT but I keep seeing there's no parts available and you would have to do a full swap of a new or used transmission.

Yup.. plus it's a pain to swap in as you have to do other stuff because it lacks some sensors that the newer ones have. It's slightly better though.. slightly but you will have the same issues with the synchro and gears.

[xquatch]

Originally Posted by SpoolinAddict

Does the N55 E9X MT cars suffer the same issues? In the future I wanted to get a higher mileage n55 e90 MT but I keep seeing there's no parts available and you would have to do a full swap of a new or used transmission.

FWIW I'm in the process of trying to source or fabricate the parts to install a GS6 45BZ out of an S55 into my 2011 335i N55. Started a thread here.