[rmcmahan]

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.

[gosi]

Wow, this is seriously impressive! And not as expensive as I would have thought. Did you sell your automatic trans?

[rmcmahan]

Thanks! I’m working on it! https://www.facebook.com/marketplace...2162287993796/

[Fasteddy1]

Nice job, glad someone finally did this!!

Pat

[TonM3]

Originally Posted by rmcmahan

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.

[xantdieselx]

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

[mikeysosa]

I'm officially very impressed.

[happyjack]

enthusiasts...bless them.

seriously impressive dude.

[MechEngineer]

How well did this hold up? I was thinking about doing this myself.

[atek]

I love hybrid builds like this! Great work!

[rmcmahan]

The build has held up well! It has been my daily driver ever since and has accumulated about 30,000 miles.

[Kernel Kurtz]

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.

[60_Driver]

Originally Posted by rmcmahan

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?

[happyjack]

Originally Posted by 60_Driver

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.

[edmfperez]

Wow. Incredibly impressive and brilliant. I have a F36 GC and you have inspired me to manual swap it soon!

[BuiltForRedline]

Did you ever get the zero gear sensor working appropriately?

[Resoelg]

Mad skills!
Excellent write up.
Thanks for sharing this.

[rmcmahan]

Originally Posted by BuiltForRedline

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.

[MDH335ixF30]

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.

[SpencerC_6MT]

Originally Posted by MDH335ixF30

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.