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Our future: swap SMG for 6-speed manual?

254K views 504 replies 103 participants last post by  jbash87 
#1 ·
So let's say you want to keep your amazing M5 for a long time ... like 10 or more years. At some time you will be long out of warranty and may face a SMG transmission failure. At that point do you think you might consider swapping out the SMG for a 6-speed manual? Considering that parts for the 6-speed cost something like $4,500 versus $8,900 for the SMG?

I enjoy reading about the classic BMWs from 20 to 25 years ago such as the E24 6 series and the E28 5 series ... and to keep those machines on the road they are always swapping out for parts from other BMWs, especially converting from automatic transmissions to manuals.

So I started to wonder ... what steps are we going to need to take to keep these beasts on the road long-term? Your thoughts?
 
#431 ·
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I swapped a 2009 m5, I have these faults. im 99% sure the dme is wired correctly and I was able to do a teach in of the YAW sensor, its coming in at the setpoint 1.8-1.81 volt with the car level and stationary. i programmed the dme zb with the zb ending in 504. any insight on what direction i should go in from here? I also did move pin 10 to pin 4 on the trans connector below the car. i did clear the faults and these are returning everytime. I know i have to do additional work with the dsc so that i am not concerned with, its just this series of dme faults, I am thinking it could be a bad dme programming. all the wires seem to pinned properly. for some reason the neutral sensor is reading as gear engaged with the trans in neutral. the trans temp sensor is reading -40 so its just showing an open circuit im guessing. any info on what direction to go in would be appreciated.
 
#434 ·
I swapped a 2009 m5, I have these faults. im 99% sure the dme is wired correctly and I was able to do a teach in of the YAW sensor, its coming in at the setpoint 1.8-1.81 volt with the car level and stationary. i programmed the dme zb with the zb ending in 504. any insight on what direction i should go in from here? I also did move pin 10 to pin 4 on the trans connector below the car.
In the middle of repinning mine now. It is much more than just moving pin 10 to 4 on the trans harness... Have you done this before?
What part number are you using for the new pins when swapping from the SMG harness to the DME? You can't simply swap wires/pins from one connector to the other. The pins/terminals are different shapes and you'll end up pushing the DME pins into the DME unit.
The old part number, 12527510671, is no longer available. FCP redirects you 61136820598 but it is not plug and play. The poka-yoke feature is on the wrong side so you have to grind it off.
 
#432 ·
Internal faults do appear to be programming related. Flash again?

Neutral sensor is the white one on top of trans. I've seen bad ones before, but ot course confirm wiring first.

The accel sensor codes you just need to complete the troubleshooting plan which calibrates everything again.
 
#436 ·
I am going to try to program it again today and I will follow up.

In the middle of repinning mine now. It is much more than just moving pin 10 to 4 on the trans harness... Have you done this before?
What part number are you using for the new pins when swapping from the SMG harness to the DME? You can't simply swap wires/pins from one connector to the other. The pins/terminals are different shapes and you'll end up pushing the DME pins into the DME unit.
The old part number, 12527510671, is no longer available. FCP redirects you 61136820598 but it is not plug and play. The poka-yoke feature is on the wrong side so you have to grind it off.
I did relocate pin 4 to 10, I actually got a harness from another M5 when i faced that issue with the pins. so i can confirm i dont have any dme pins not making contact.

The transmission harness has to be completely remade. None of the existing wires go to the correct pins. Post what you have wired where.
i used an actual m5 manual transmission harness, not a smg harness converted.
 
#440 ·
@trinispec I'm a bit confused. You used a 6MT engine harness but still swapped pins 10 and 4 on the transmission side (X60681)?

Hope the flash is all that is needed. I'm dreading the thought of potentially troubleshooting wiring issues. I'm taking my sweet time w/ it, verifying continuity, and documenting everything though. So I should be ok 🤞
 
#450 ·
I wonder If your ECU is populated to use the transmission oil temp sensor input.

I've done 3 cars that were early build of 2005 and the ECU PCB was different compared to 03/07+ cars.
From what I can tell from wiring diagrams there was a change in 08/05, but I'm not sure on the specifics. I've had to go back and forth on a ton of different diagrams and I can't keep them all straight.
I can check my ECU wiring for a specific wire color/pin position if you know what to look for and report back.
 
#463 ·
I was able to work through the sensor faults for the manual trans but I am still dealing with these codes. I was able to probe the wires from the actual longitudinal sensor under the seat but Im still getting these dme codes. initially two of the dme internal faults went away when I pulled out the pins for the longitudinal sensors which leads me to believe the 09 might utilize different wiring. any info on where I should look?
 

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#470 ·
Gearbox and first package of parts arrived a while ago, but I’ve been a bit tied up with life so only managed to make a start this week. I couldn’t find a gearbox locally (Aus) so ended importing one from the UK out of an e92

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Output side had a fair amount of build up around the selector rod and output shaft. Selector rod seal was easy enough to get out

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Output flange nut is on real good - wasn’t able to get it off to access the output shaft seal. Will leave it soaking it in wd for a few days and then give it another crack

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Input side looked fine but did the seal anyway whilst the box was out

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Went with the e60 short shifter. Haven’t decided on shift knob yet - ideally would like the f10 knob, but finding it hard to justify an extra $300 vs zhp just for illumination

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Next step is blocking off the oil cooler ports. Was planning to just tap and install plugs, but having second thoughts now incase I want to retrofit the oem cooler down the line…
 

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#471 · (Edited)
Interesting thread. I have an original all stock manual car, US spec, and was looking for one after finding out around 2014-2015 they did make a manual (would have still bought a SMG car even if the manual ones didn't exist). Always liked how the E60 looked. Saw a E60 M5 (interlagos blue SMG car with white interior) in May 2008 for the first time, was still in college, I knew one day I would own one. Haven't driven a SMG car yet but interested in owning one and keeping it SMG even if it means having to spend same amount it would cost for a manual swap to fix it. These cars were rare when they came out, manual or not, and even more rare now with all the parting outs that has been happening because of failed rod bearings, stuck open injectors, failed SMGs, etc. I think in total I have seen less than 8 E60 M5s in the wild since they came out and maybe 4 M6 cars here in DFW, have seen more E39 M5s out there. These cars are special, there will never be anything like it made again and I'm just happy to own one.
 
#473 ·
Yeah fair call - Ive decided to just do the same. Measured the inner bore of the holes to be 14.5mm so I ordered a pair of aluminium M16x1.5 plugs over the weekend. Will just leave the pump in place for now

Managed to get the output flange nut off and took out/inspected the old seal. Explains the leak on the output side

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Gently massaged the new seal in and got it sitting nice and flush. Also noticed that I’m missing one of the gearbox support bracket bolts

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There’s a fair bit of surface corrosion on the flange from 15 years on salted UK roads. Price for a new one is $480 so will just give her a birthday and pop her right back in when the time comes

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#477 · (Edited)
FYI for anyone contemplating a SMG > 6MT swap, you may be aware the E60 M5 OEM shifter carrier (part no 25112283195) has been backordered with no ETA at all the typical online sources (ECS etc) for quite some time, which is problematic since its unique to the S85 engine.

Good news! Recently I was able to find new E60 M5 OEM shifter carrier on ebay: New Genuine BMW Shifting Arm H25110 OE 25112283195 | eBay. Just received the part and it appears to be perfect fit, and is bearing the correct part number in the casting. One more piece found, now onto finding a reasonably priced LUK OE dual mass flywheel!
 
#489 ·
I'm just attaching the appropriate caution to the poster who has been lead to believe it's exactly the same thing-which it definitely isn't.
S65 flywheel/clutch are a direct fit and readily available. Just can't mix and match.
At no point did I say they were the same thing.

I appreciate your input. It is definitely worth noting. There is also something to be said about the many many years of car enthusiasts using lightweight flywheels for performance applications, or manufacturers choosing to use heavier fly wheels for comfort. We weren't on the design team so we cannot know why they chose what they did.

I believe that there are risks to any modification one makes to a vehicle. I also think it is fair to assume that if someone is deciding to manual swap a car they too understand that there are risks.
 
#490 ·
Clutch + FW is 50.6 lbs stock, 47.2 lbs for the M3. Materially different, sure - but not night and day different. Everyone has made valid points but even being on the program team would end up with a discussion/tradeoff on durability and reliability, and it comes down to user preference. Like the carnies used to say at the fall fair where I grew up - Ya pay yer money, ya git yer choice.
 
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