THE LARGEST BMW 2-SERIES FORUM ON THE PLANET
2Addicts
2Addicts
BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read
2Addicts | BMW 2-Series forum Technical Topics N55 (M235i) Engine, Transmission, Exhaust, Tuning M235i xDrive Manual Swap

Post Reply
 
Thread Tools Search this Thread
      04-21-2020, 02:05 PM   #1
rmcmahan
New Member
30
Rep
5
Posts

Drives: BMW M235i
Join Date: Mar 2020
Location: US

iTrader: (0)

M235i xDrive Manual Swap

As you may know, the M235i was never offered with xDrive and a manual transmission. That's unfortunate for myself and the 3 other people in the world that BMW probably thought would buy one. Because the 435i and 335i both can be configured that way, I had suspicions that a manual swap could be done somewhat easily. After cross-referencing part numbers on realoem, my suspicions were confirmed. Coding the car for a manual was a bit more of an unknown because I have not seen anyone do a manual swap on an F chassis yet. After reading into many E chassis swaps along with all of the information available about E-Sys and ISTA on these forums, I decided to go ahead with the swap.

The AWD manual transmission that is found in the F30 335i and the F32 435i (GS6x45BZ) is the missing piece of the puzzle. This is generally the same gearbox as the GS6-45BZ that is in the 6MT RWD M235i, except that the output shaft is mated to a transfer case rather than the output flange to a driveshaft.

Other than the transmission, all the parts needed are what would be in a manual M235i. The big pieces are:
Slave Cylinder
Dual Mass Flywheel
Clutch Assembly
Clutch Line and Grommets
Shifter Mechanism Assembly
Pedal Assembly
Various Bolts (Manual uses longer bellhousing bolts than automatic)
Electrical Connectors, Pins, and Wire

I am attaching my spreadsheet that goes more in depth with part numbers.

Now, on to the swap. Disassembling and assembling the drivetrain has already been documented well, so I will focus on what is different and things that I learned. Most procedures can also be found on newtis.info or within ISTA.

I took the transfer case and mount out along with the automatic transmission. Once the assembly was out, I moved the transfer case over to the manual transmission. Now is a good time to change the fluid.

The automatic transmission uses an oil cooler attached to the radiator, and the manual does not. I removed the lines to the oil cooler, but I left the cooler there with plugged ports. When the time comes to flush the coolant, I will change the lines and remove that oil cooler.

With the flywheel and clutch installed, I then routed the clutch line and installed the pedal box. In order to do this, the accelerator pedal needs to be taken out so the carpet can be pulled up enough to get the line through the bulkhead. I found that it is easiest to have someone under the car that can pull the line while someone else is pushing it through. The master cylinder also has a supply line that routes from the brake fluid reservoir. The holes where these lines route have plugs that should be replaced with the correct grommets.

Now is the best time to do all the wiring. I will attach a spreadsheet with all of the connections. For the connections to the DME, I used the pre-existing loom that goes to the transfer case controller and the automatic transmission controller.

I then was able to proceed with installing the transmission. The automatic has a different support inside of the center console to mount the gear selector to. I was afraid that this would interfere with the shifter in 5th and 6th gear, but it just narrowly misses. No need to replace the center console.

In buttoning up the exhaust, I found that the downpipe has a different mounting tab for the manual than the automatic due to the different bellhousing thickness. I used spacers to account for this for the time being.

Here is where things get interesting. I started with VO Coding the ECUs to remove the 2TB code. Then in ISTA, I ran the “Compare equipment specification” ABL in Vehicle Management->Service Functions->Powertrain->Engine Electronics. This will reset the equipment learned into the DME and initialize code for a manual transmission rather than an automatic. I then reset adaptations.
At this point, the vehicle would go into a ‘start sequence’ where everything would prime, but the starter would not turn. The reason was that the FEM was not energizing the starter. After trying many different things to get it to work, I ended up coding the FEM back to automatic and the engine started right up.
The reverse light switch connects directly to the FEM, so that does not function with the FEM coded for an automatic. I ended up getting it to work by coding it back to manual with the type key 1J73, which corresponds to the RWD 6MT version.
At this point, the only fault codes were pertaining to the zero-gear sensor not being learned in. ISTA seems to figure out what functions to populate the user interface with based on the VIN, so I am not able to learn in that sensor at this time… I can deal without auto stop/start for the time being.
I was still getting a “Chassis function restricted” control message on the iDrive screen and I could not drive in sport mode. In ISTA, I read the check control messages and saw that the issues pertained to EDC and Dynamic Drive. I reverted the EDC and ICM back to automatic VO, then reset the EDC in ISTA.

I have put about 1,000 miles on the car since the swap and things are working as I expected, but I do have a few goals to make it perfect:

1.) I have had a really hard time finding the connector for the zero-gear sensor, so I made my own with some structural adhesive. If anyone knows where to find that connector, please let me know.

2.) If anyone has any advice on making the coding better so that all of the ECUs can operate with the same type key and VO, I am open to suggestions.

3.) I was going to try flashing a RWD VIN to the VCM to see if ISTA would then allow me to learn in the zero-gear sensor. If anyone has a better solution, let me know. I will update my findings later.
Attached Images
            

Last edited by rmcmahan; 04-24-2020 at 04:39 PM..
Appreciate 14
      04-21-2020, 02:47 PM   #2
gosi
Private First Class
96
Rep
147
Posts

Drives: M240
Join Date: Nov 2019
Location: Slovenia

iTrader: (0)

Wow, this is seriously impressive! And not as expensive as I would have thought. Did you sell your automatic trans?
Appreciate 0
      04-21-2020, 03:00 PM   #3
rmcmahan
New Member
30
Rep
5
Posts

Drives: BMW M235i
Join Date: Mar 2020
Location: US

iTrader: (0)

Thanks! I’m working on it! https://www.facebook.com/marketplace...2162287993796/
Appreciate 0
      04-21-2020, 04:15 PM   #4
Fasteddy1
Private First Class
60
Rep
140
Posts

Drives: 2017 M240i
Join Date: Nov 2010
Location: MN

iTrader: (1)

Nice job, glad someone finally did this!!

Pat
Appreciate 0
      04-21-2020, 04:37 PM   #5
TonM3
Lieutenant
TonM3's Avatar
United_States
249
Rep
504
Posts

Drives: 2006 E46 M3 / 2017 M240
Join Date: Apr 2020
Location: Bethesda, MD

iTrader: (0)

Quote:
Originally Posted by rmcmahan View Post
As you may know, the M235i was never offered with xDrive and a manual transmission. That's unfortunate for myself and the 3 other people in the world that BMW probably thought would buy one. Because the 435i and 335i both can be configured that way, I had suspicions that a manual swap could be done somewhat easily. After cross-referencing part numbers on realoem, my suspicions were confirmed. Coding the car for a manual was a bit more of an unknown because I have not seen anyone do a manual swap on an F chassis yet. After reading into many E chassis swaps along with all of the information available about E-Sys and ISTA on these forums, I decided to go ahead with the swap.

The AWD manual transmission that is found in the F30 335i and the F32 435i (GS6x45BZ) is the missing piece of the puzzle. This is generally the same gearbox as the GS6-45BZ that is in the 6MT RWD M235i, except that the output shaft is mated to a transfer case rather than the output flange to a driveshaft.

Other than the transmission, all the parts needed are what would be in a manual M235i. The big pieces are:
Slave Cylinder
Dual Mass Flywheel
Clutch Assembly
Clutch Line and Grommets
Shifter Mechanism Assembly
Pedal Assembly
Various Bolts (Manual uses longer bellhousing bolts than automatic)
Electrical Connectors, Pins, and Wire

I am attaching my spreadsheet that goes more in depth with part numbers.

Now, on to the swap. Disassembling and assembling the drivetrain has already been documented well, so I will focus on what is different and things that I learned. Most procedures can also be found on newtis.com or within ISTA.

I took the transfer case and mount out along with the automatic transmission. Once the assembly was out, I moved the transfer case over to the manual transmission. Now is a good time to change the fluid.

The automatic transmission uses an oil cooler attached to the radiator, and the manual does not. I removed the lines to the oil cooler, but I left the cooler there with plugged ports. When the time comes to flush the coolant, I will change the lines and remove that oil cooler.

With the flywheel and clutch installed, I then routed the clutch line and installed the pedal box. In order to do this, the accelerator pedal needs to be taken out so the carpet can be pulled up enough to get the line through the bulkhead. I found that it is easiest to have someone under the car that can pull the line while someone else is pushing it through. The master cylinder also has a supply line that routes from the brake fluid reservoir. The holes where these lines route have plugs that should be replaced with the correct grommets.

Now is the best time to do all the wiring. I will attach a spreadsheet with all of the connections. For the connections to the DME, I used the pre-existing loom that goes to the transfer case controller and the automatic transmission controller.

I then was able to proceed with installing the transmission. The automatic has a different support inside of the center console to mount the gear selector to. I was afraid that this would interfere with the shifter in 5th and 6th gear, but it just narrowly misses. No need to replace the center console.

In buttoning up the exhaust, I found that the downpipe has a different mounting tab for the manual than the automatic due to the different bellhousing thickness. I used spacers to account for this for the time being.

Here is where things get interesting. I started with VO Coding the ECUs to remove the 2TB code. Then in ISTA, I ran the “Compare equipment specification” ABL in Vehicle Management->Service Functions->Powertrain->Engine Electronics. This will reset the equipment learned into the DME and initialize code for a manual transmission rather than an automatic. I then reset adaptations.
At this point, the vehicle would go into a ‘start sequence’ where everything would prime, but the starter would not turn. The reason was that the FEM was not energizing the starter. After trying many different things to get it to work, I ended up coding the FEM back to automatic and the engine started right up.
The reverse light switch connects directly to the FEM, so that does not function with the FEM coded for an automatic. I ended up getting it to work by coding it back to manual with the type key 1J73, which corresponds to the RWD 6MT version.
At this point, the only fault codes were pertaining to the zero-gear sensor not being learned in. ISTA seems to figure out what functions to populate the user interface with based on the VIN, so I am not able to learn in that sensor at this time… I can deal without auto stop/start for the time being.
I was still getting a “Chassis function restricted” control message on the iDrive screen and I could not drive in sport mode. In ISTA, I read the check control messages and saw that the issues pertained to EDC and Dynamic Drive. I reverted the EDC and ICM back to automatic VO, then reset the EDC in ISTA.

I have put about 1,000 miles on the car since the swap and things are working as I expected, but I do have a few goals to make it perfect:

1.) I have had a really hard time finding the connector for the zero-gear sensor, so I made my own with some structural adhesive. If anyone knows where to find that connector, please let me know.

2.) If anyone has any advice on making the coding better so that all of the ECUs can operate with the same type key and VO, I am open to suggestions.

3.) I was going to try flashing a RWD VIN to the VCM to see if ISTA would then allow me to learn in the zero-gear sensor. If anyone has a better solution, let me know. I will update my findings later.
Holy crap!

This is amazing, congrats.
__________________
E46 -> E90 -> F30 -> F23
Appreciate 0
      04-21-2020, 05:10 PM   #6
xantdieselx
Kingslayer
xantdieselx's Avatar
No_Country
411
Rep
1,479
Posts

Drives: 23' M3 Base
Join Date: Jun 2008
Location: SWFL

iTrader: (0)

Wow...just wow. That's impressive. Good luck working out all the kinks.
__________________

Previous Cars: 2008' 135i, 2010' 328i, 2013' 328i, 2016' M235i, 2017' X1, 2019' M240i
Current Cars: 2019' X3, 2021' M3 Comp
Appreciate 0
      04-23-2020, 07:45 PM   #7
mikeysosa
Second Lieutenant
mikeysosa's Avatar
United_States
163
Rep
216
Posts

Drives: 2016 BMW M235i
Join Date: Oct 2019
Location: Cocoa Beach, FL

iTrader: (0)

Garage List
1995 Mazda Miata  [0.00]
2016 BMW M235i  [0.00]
I'm officially very impressed.
__________________
Appreciate 1
      04-24-2020, 07:21 AM   #8
happyjack
Captain
happyjack's Avatar
United_States
1657
Rep
922
Posts

Drives: '21 F87 M2C 6MT
Join Date: Nov 2017
Location: old line state

iTrader: (0)

Garage List
enthusiasts...bless them.

seriously impressive dude.
Appreciate 0
      07-04-2022, 09:38 PM   #9
MechEngineer
Enlisted Member
5
Rep
31
Posts

Drives: M235i xdrive
Join Date: Aug 2018
Location: Southeast Michigan

iTrader: (0)

How well did this hold up? I was thinking about doing this myself.
Appreciate 0
      07-06-2022, 05:15 PM   #10
atek
I like biscuits
atek's Avatar
United_States
164
Rep
250
Posts

Drives: bmw m235i
Join Date: Jan 2022
Location: TX

iTrader: (0)

I love hybrid builds like this! Great work!
Appreciate 0
      07-06-2022, 05:35 PM   #11
rmcmahan
New Member
30
Rep
5
Posts

Drives: BMW M235i
Join Date: Mar 2020
Location: US

iTrader: (0)

The build has held up well! It has been my daily driver ever since and has accumulated about 30,000 miles.
Appreciate 3
02M3ForMe4257.00
MLJR235116.50
      07-06-2022, 06:12 PM   #12
Kernel Kurtz
Major
Kernel Kurtz's Avatar
345
Rep
1,012
Posts

Drives: 2020 M240i xDrive
Join Date: Sep 2007
Location: Winnipeg, Canada

iTrader: (0)

This is one of the more epic posts I've seen here recently. So cool you got it mostly working, and thanks for sharing!

I'm one of those other three people who would have bought this in factory trim if it was available. My last three cars, all 3 Series, were xDrive manuals. I was genuinely disappointed I could not get this configuration in the 240. I went with the xDrive this time because it is a blast in the winter, and I had never owned a car with a modern auto with paddles and wanted to cross it off my bucket list. I do very much enjoy my current car, but there are days when I definitely do miss that third pedal. I don't think I will be trying this at home, but if someone were to offer this as an aftermarket build service I would seriously consider it.

Cheers! Look forward to updates.
Appreciate 1
VAcurler116.00
      07-07-2022, 07:46 PM   #13
60_Driver
Private First Class
60_Driver's Avatar
United_States
59
Rep
188
Posts

Drives: 2016 M235i 6mt vert
Join Date: Feb 2021
Location: NH

iTrader: (0)

Quote:
Originally Posted by rmcmahan View Post
The build has held up well! It has been my daily driver ever since and has accumulated about 30,000 miles.
Seriously impressive undertaking and great results over 30k. I understand that bmw awd is rear wheel biased. Do you feel that with this conversion?
Appreciate 0
      07-08-2022, 06:59 AM   #14
happyjack
Captain
happyjack's Avatar
United_States
1657
Rep
922
Posts

Drives: '21 F87 M2C 6MT
Join Date: Nov 2017
Location: old line state

iTrader: (0)

Garage List
Quote:
Originally Posted by 60_Driver View Post
Seriously impressive undertaking and great results over 30k. I understand that bmw awd is rear wheel biased. Do you feel that with this conversion?
you dont need a manual to feel it. even with x-drive if you turn off DSC, you will feel it. unless it's raining i almost always drove my 228ix without DSC...and even that 4-banger would kick out the tail if i got on it in a turn.
__________________

my garage: '23 G05 xDrive40i m-sport; '21 F87 M2C, 6MT; '17 F25 x-drive28i SAV; '15 F55 mini hatch 5-door
retired: '87 E30 MT 'vert; '92 E36 sedan; '99 E36 MT 'vert; '06 E90 x-drive sedan; '07 E83 x-drive30 SAV; '09 E91 x-drive wagon; '12 E89 Z4 MT M-sport; '15 F22 sport line
Appreciate 0
      12-08-2022, 04:24 PM   #15
edmfperez
breaks things
13
Rep
47
Posts

Drives: 2007 335i Montegoblau 6MT
Join Date: Feb 2015
Location: Austin, TX

iTrader: (0)

Wow. Incredibly impressive and brilliant. I have a F36 GC and you have inspired me to manual swap it soon!
Appreciate 0
      01-01-2023, 12:08 PM   #16
BuiltForRedline
New Member
United_States
2
Rep
10
Posts

Drives: 06-330Ci ZHP
Join Date: Jan 2022
Location: California

iTrader: (0)

Did you ever get the zero gear sensor working appropriately?
Appreciate 0
      01-02-2023, 07:51 PM   #17
Resoelg
Lieutenant
Resoelg's Avatar
United_States
238
Rep
431
Posts

Drives: 2024 M2 ZV-Blue
Join Date: Jun 2020
Location: Philadelphia

iTrader: (3)

Garage List
24 G87  [10.00]
Mad skills!
Excellent write up.
Thanks for sharing this.
Appreciate 0
      01-06-2023, 08:36 AM   #18
rmcmahan
New Member
30
Rep
5
Posts

Drives: BMW M235i
Join Date: Mar 2020
Location: US

iTrader: (0)

Quote:
Originally Posted by BuiltForRedline View Post
Did you ever get the zero gear sensor working appropriately?
I ended up finding the right connector to the sensor: Mfg #12527513331
But I have not managed to learn in the sensor. I only get an auto stop/start malfunction alert when turning the engine off, which hasn’t been terribly inconvenient. It is still on my list though.
Appreciate 0
      12-04-2023, 02:30 PM   #19
MDH335ixF30
F30_335ix_Manual
0
Rep
1
Posts

Drives: BMW 335i f30
Join Date: Dec 2023
Location: Michigan

iTrader: (0)

Ref: M235i Manual swap

Can you tell me if an F30 335ix transfer case can be mounted to any version of the ZF rear wheel drive trans? I have a bad 2nd gear syncro. And parts are not available. With very few used ix manuals out there I'm just looking into options.
Might have to swap guts out of a good used RWD trans.
Appreciate 0
      12-11-2023, 02:14 PM   #20
SpencerC_6MT
Second Lieutenant
SpencerC_6MT's Avatar
United_States
197
Rep
238
Posts

Drives: '17 M240i 6MT
Join Date: May 2017
Location: San Diego, CA /// Tuscaloosa, AL

iTrader: (0)

Garage List
2017 BMW M240I  [0.00]
Quote:
Originally Posted by MDH335ixF30 View Post
Can you tell me if an F30 335ix transfer case can be mounted to any version of the ZF rear wheel drive trans? I have a bad 2nd gear syncro. And parts are not available. With very few used ix manuals out there I'm just looking into options.
Might have to swap guts out of a good used RWD trans.
Did I little digging, since you made me curious. It seems like xDrive transmissions have an extra bit of metal on the back where the transfer case bolts up. They technically have different names too, GS6-45BZ vs GS6X45BZ. But the ratios and guts should be identical, as far as I'm aware.

RWD: https://wolfautoparts.com/6speed-man...2-ps95441.html

xDrive: https://bimmercat.com/bmw/en/search/...23/83222156969

The xDrive diagram says it's the B58 trans, but it has the N55 starter cutout for the bellhousing, so I believe it's mislabeled.
__________________
2017 BMW M240i 6MT Slicktop | Wavetrac 3.46:1 Limited-Slip Diff - DinanTRONICS Sport Boost Controller - H&R Sport Springs - Millway Street Camber Plates - Agency Power Intake w/ Paradigm Engineering Turbo Inlet
Appreciate 0
Post Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 07:04 AM.




2addicts
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST