SMG to 6MT Conversion

[sapote]

Bell housing machining: The stock manual box used 2 C-clips and rubber caps to hold the Reverse and 5/6 gears detent pins. Machining the grooves for the C-clips is not easy and people had tapped threads for 2 bolts instead (some used the NPT plug bolts which I think could crack the thin and soft aluminum female threads) . I found the following method is good and looks nice. I wish to give credit to the creator but I forgot where I got it.

Detent Cap: An M22 thread is tapped into the detent hole where an OE E46 M3 differential drain plug is used instead of the original Getrag manual transmission rubber cap and circlip. This is done for ease of install and final aesthetics. The rubber caps are fragile and often get torn or bent in the process. The differential drain plug is a perfect fit and has the correct depth for proper detent spring compression.

[pawelgawel]

that looks clean!! nice job

[pawelgawel]

can someone specify which COMPRESSION SPRINGS I should swap and replace while the unit is all out?? Im getting a little confused with that part.
I know the position sensor has a different spring and pin in that inlet, aside from this, is there anything else I should change?

[sapote]

can someone specify which COMPRESSION SPRINGS I should swap and replace while the unit is all out?? Im getting a little confused with that part.
I know the position sensor has a different spring and pin in that inlet, aside from this, is there anything else I should change?

3 compression springs that you want to renew:
* odd/even shifter shaft detent: 23317511337
* Reverse detent: 23111222720
* 5/6 gear detent: 23311228393

There is no position sensor in 6mt; only the SMG has 3 sensors: slave clutch, shift shaft linear (odd/even gears) sensor and angular sensor (R, 1/2, 3/4. 5/6 planes).

[pawelgawel]

Ok, just what I thought ... I have an extra bell-housing already prepped on the side so the detents are fresh, just the 337 area needs a new one. Since the smg uses a blind plug(#5,6,7), how does the MT cap that (#8,10,9)?

I also meant the Gear ID switch, is there anything inside or is that require just the tap? (stupid questions sorry)

[ATB88]

Ok, just what I thought ... I have an extra bell-housing already prepped on the side so the detents are fresh, just the 337 area needs a new one. Since the smg uses a blind plug(#5,6,7), how does the MT cap that (#8,10,9)?

I also meant the Gear ID switch, is there anything inside or is that require just the tap? (stupid questions sorry)

For the gear position sensor (GPS), this diagram is actually misleading/incorrect. The gear ID switch (part 12) and the locking pin/thrust pin/spring combo (parts 8/9/10) all go into the same hole which is the one that you tap threads into. Whereas this diagram shows them going into different holes. The hole that the GPS is going into on this diagram does not exist. The thrust pin (10) is what pushes the gear position sensor in when you're in gear, so they all need to go in the same place. It really bothered me when doing this job that this diagram was wrong lol.

[pawelgawel]

For the gear position sensor (GPS), this diagram is actually misleading/incorrect. The gear ID switch (part 12) and the locking pin/thrust pin/spring combo (parts 8/9/10) all go into the same hole which is the one that you tap threads into. Whereas this diagram shows them going into different holes. The hole that the GPS is going into on this diagram does not exist. The thrust pin (10) is what pushes the gear position sensor in when you're in gear, so they all need to go in the same place. It really bothered me when doing this job that this diagram was wrong lol.

THank YOU! I though that might be the issue.. Ok im all god now. thanks!

[sapote]

I also meant the Gear ID switch, is there anything inside or is that require just the tap? (

Why do you want to get all the trouble of adding the GPS sensor to the 6mt?

[pawelgawel]

Why do you want to get all the trouble of adding the GPS sensor to the 6mt?

just want to make sure everything is done properly.. its a little expensive so if I could avoid doing it I would. should I just replace the spring with another SMG one and call it a day?

[sapote]

just want to make sure everything is done properly.. its a little expensive so if I could avoid doing it I would. should I just replace the spring with another SMG one and call it a day?

Many people skip this conversion and just replace the stock SMG spring with new one. Do the conversion could lead to oil leak for not much gain.

[pawelgawel]

whats the gain in doing it? if I opt out, is there something that needs to be done while reflashing ecu?

[sapote]

I think the GPS is related to the cruise control and this can be sealed with coding.

[pawelgawel]

anyone have an idea where I can get one of the bearings within the housing? Ill post a photo with the one missing. I purchased the converted housing without it, I suspect I can reuse my current one in my car once its out, but in case I'd like to make sure there is another option.. its held on a retainer from what I see..

[sapote]

Don’t use a donor bell housing - see my post about the damage it can cause. Convert your BH to match.

[George Hill]

whats the gain in doing it? if I opt out, is there something that needs to be done while reflashing ecu?

The GPS will tell the DME if the transmission is in neutral. I always add them in my conversions, but if you want to address some coding differences and don't plan to pull it into neutral with the cruise on you'll be fine.