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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?
 
#3 ·
Ditto. I bought a 6 speed for this very reason. Plan to keep it 10 or so years. Loved the SMG but worried about it holding up long term. Lots of folks will tell you SMG is the only way to go but for me durability was a consideration as I don't turn over cars ever 2-5 yrs like a lot of people do.

-Brian
 
#4 ·
6speed in an M5..is embarrassing the worst idea BMW ever had...imagine such a heavy car with a stick?? it reminds me of a Chrysler New Yorker with a 392 Hemi and a four speed, it's exciting as getting a kiss from your grandmother and she slips you the tongue !!!!!
 
#5 ·
Since there are many exotic and sports cars with single clutch sequential gearboxes (similar to the M5's SMG), I think that down the line there will always be mechanics that will know how to maintain/fix/replace them. While it may be harder to find people to do so, and while the SMG may not be completely reliable in the long term, I would say it is still safe to keep an SMG M5 around for many years. Plus, with most performance cars going the dual clutch route, owning a car with SMG may be very rare/desired in the future.

Regarding the 6 speed transmission, while it is easier to maintain manual transmissions in the long term in most cases, I don't necessarily think this will be true with the M5. The M5's manual transmission was not designed for this engine, and that is evident with transmission and clutch heat issues when driven enthusiastically. Who knows if the M5's 6MT is really designed for the long run, and if it does break many years from now, parts may be hard to come by.


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#7 ·
I believe so. I think the clutch was slightly modified to take the extra 100 horsepower, but very little was done.



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#8 ·
Isn't the SMG just a manual transmission with a hydraulically activated clutch? So the only essential difference in basic components is the hydraulic system which surely doesn't necessitate a completely new tranny when it fails? How much does an SMG hydraulic pump cost?
 
#9 · (Edited)
That's is one of the questions I've asked myself a few times, and I think the only way to solve this problem is to buy a 6 speed MT M5 in the states and ship it to Europe. That's defintitely the easiest and cheapest way, and the prices will drop pretty soon:D

It would be nice to see a video of the M5 with SMG vs. a M5 with the manual transmission, it's clear that the SMG is faster, but it would be nice to see if it really makes such a difference.:byebye:
 
#10 ·
Interesting subject.. I always wanted to do the swap.

To answer some question in this thread, the e60 m5 uses the 545 manual trans with some different components like a different face where it attaches to the engine and a different clutch.

Dealerships are known to just replace the whole SMG unit which costs a lot. Famous problems in the E60 m5 and the m6 are:

- clutch release bearing which is not an SMG problem at all. It's purley a clutch bearing going bad some say due to the bearing not being greased properly!

- failure to fire the engine up due to the car being in gear = the car can't engage 1st gear due to:

1) not enough hydraulic fluid in the sys. There might be a leak. Must find where the leak is coming from.
2) SMG bump might not be working. It's not that hard to replace and part costs around $400!
3) relay goes bad that activates the bump. Never came across it! Known problem in the E46 m3 though, $20 dollar fix!
4) sensors like: clutch position sensor (reads the position of the clutch), pressure sensor (reads the pressure of the SMG fluid).

One good thing about SMG III is that you can buy almost everything separately unlike SMG II $ I. I read that someone had a leak coming from the pressure sensor that goes in the hydraulic unit and had to replace the whole unit cuz it's not available that was an E46 m3! Thank god BMW did something about it.

In short, the smg is not rocket science! It just needs someone who understands it and has the right tools to work on it.
 
#13 ·
I don't know if that is possible, but if you want a 500 horsepower NA M car with DCT, you could always pick up an E90 M3 and put the Dinan 4.6 liter stroker in it!



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#12 ·
you are safe for at least 10 years, by law BMW is required to make parts avaliable for all vehicles for at least 10 years. since the e60 was in production through 2010 and relatively unchanged, that gives us until 2020. if similar vehicles are any indictor of parts avability , and considering the e60 was the most successful m5 ever, we'll probally have another 5-10 years of good aftermarket replacement parts after that. also as stated, the smg III really isn't too much different than a regular stick, infact it's much less a headache than other dual clutch smgs that are available today. if I were to be afraid of anything failing and being unable to locate a part, it would be with any of the cars electrically operated components.
 
#17 ·
I disagree on two counts.
1) I love it that I own a full size sedan with a 6 speed. My Viper is no smaller and has a 6 speed.
2) What difference is it that the manual was not made for the care. There are plenty of car companies (porsche) that swap components. This is called economies of scale and makes cares more affordable to produce. I understand that the v10 was incredibly expenive to produce.
 
#18 · (Edited)
I disagree on two counts.
1) I love it that I own a full size sedan with a 6 speed. My Viper is no smaller and has a 6 speed.
2) What difference is it that the manual was not made for the care. There are plenty of car companies (porsche) that swap components. This is called economies of scale and makes cares more affordable to produce. I understand that the v10 was incredibly expenive to produce.
I disagree on you disagreeing. :D

1) hmmm Your viper is no smaller? ?????? The BMW weighs 600lbs more and is 17 inches longer! Might want to check your math on that.
2) The difference is that the gear ratios are improperly spaced for the M5's engine, so when you shift it drops you too low in the rpm range and out of your powerband, and this is why the SMG car is quite a bit faster than the 6 speed car in a straight line.
 
#19 ·
I can't stand SMG for daily driving! I have a 6 speed and I love it. I'm a REAL driver and actually race motorcycles for a living. With SMG I didn't feel attached to the car, I felt distant. I prefer a 6 speed because then I am truly in control of everything. It may be slightly slower but I can assure I would beat 99% of you with same setups. I did notice the rpms dropping a little low but that's nothing a flash with raised revlimit can't fix!
 
#21 ·
SMG to Manual Conversion

I am quite positive a conversion can be accomplished if you have the funding and technical ability to pull it off. I wanted a 6 speed and was fortunate to find one. It fits my driving style well and potential maintenance issues. I am positive the SMG will out-shift me any day of the week. I really don't care! The M brand is something we can all rally around in:santasmile2:stead of separating ourselves over who has the better car because of SMG vs. 6 speed. Don't want to hi-jack the thread but I am much more concerned about the better/safer driver.
 
#22 ·
The SMG is quite brilliant IMO. After owning the car for 3 years, I still can't get over the fact on how the SMG is able to mimmick manual shifting without a 3rd pedal. No way in hell can a 6 speed driver shift faster, cleaner and rev macht the SMG. The 6 speed option was nothing more than BMW's response to the public outcry on the SMG. But frankly, I think all that outcry was from old foggies that didn't know how to drive the SMG, they were treating the SMG as a regular automatic transmission, experiencing tranny/rear end slamming, etc.

Anyways, 10-20 years down the road, if the tranny fails, I'm sure there won't be a shortage of solutions offered by BMW or the countless aftermarket vendors out there. Converting a SMG M5 into a 6 speed seems to be a lot of work. Just to figure out how to mount the 3rd pedal that will provide the perfect pivot angle to manually actuate the clutch assembly. But, I won't be surprised if an aftermarket vendor does come out with a conversion kit, just a matter of time.
 
#23 ·
The SMG is quite brilliant IMO. After owning the car for 3 years, I still can't get over the fact on how the SMG is able to mimmick manual shifting without a 3rd pedal. No way in hell can a 6 speed driver shift faster, cleaner and rev macht the SMG. The 6 speed option was nothing more than BMW's response to the public outcry on the SMG. But frankly, I think all that outcry was from old foggies that didn't know how to drive the SMG, they were treating the SMG as a regular automatic transmission, experiencing tranny/rear end slamming, etc.

I am no old foggie at the age of 26. ;) Like I said before I am sure I could outdrive 99% of you with or without SMG. I drive for a passion and fun. Yes SMG is more LOGICAL as it is much faster then a human but this is not a race car its a car about FUN! If i were racing and there was money on the line of course I would pick SMG but I didn't buy this car to compete in anything or race it seriously. I have cheap easy fast cars for that. I drive this car every day and I just got annoyed at how the SMG lagged just like the FBW. I like to FEEL connected to the car which is a personal preference obviously but because I am a REAL driver. Im glad you enjoy your SMG and it is a cool application for racing but again for a daily driven non race car I just don't care for it.
 
#25 ·
^^^ you are exactly right that US drivers just use the car as a daily commuter (~60mph every day)... myself included. A lot of people mention that the 6 speed will overheat under 15-20 mins of hard driving. This only makes sense if you have the M5 as a dedicated weekend/track car. If you are going to drive it to work and back, overheating is not a valid argument. hell, i'd be lucky if i can get 1 minute of continuous "hard" driving a day in traffic. I would argue against the 6 speed being more fun tho. SMG was more enjoyable to me, but i ended up with a 6speed because of reliability reasons. It's pretty obvious, there's less stuff to break.

it's fast enough(bad gearing, slower shifting) for my purposes and i won't ever get a chance to overheat it. I drive it everyday and don't have another car so i can't afford to deal with red/yellow cogs of *****.

i woudn't bother swapping the SMG, maintenance is part of the cost of performance.
 
#26 · (Edited)
First, Sephiroth FTW. I'm assuming you've watched Advent children by now?
If you are going to drive it to work and back, overheating is not a valid argument. hell, i'd be lucky if i can get 1 minute of continuous "hard" driving a day in traffic. I would argue against the 6 speed being more fun tho. SMG was more enjoyable to me, but i ended up with a 6speed because of reliability reasons. It's pretty obvious, there's less stuff to break.
I haven't had the opportunity to sit in a SMG E60 yet, still just a lurker looking for a good deal, so I can't comment on whether it's more enjoyable for me. What I can comment on is that I can't imagine not missing a stick shift and a clutch pedal.

i woudn't bother swapping the SMG, maintenance is part of the cost of performance.
this is more often true than I'd like haha.
 
#27 ·
First, Sephiroth FTW. I'm assuming you've watched Advent children by now?

I haven't had the opportunity to sit in a SMG E60 yet, still just a lurker looking for a good deal, so I can't comment on whether it's more enjoyable for me. What I can comment on is that I can't imagine not missing a stick shift and a clutch pedal.


this is more often true than I'd like haha.
haha yeah, i saw advent children awhile back.

all i have to say for SMG is instant throttle blip/perfectly rev matched down shifts... it's a beautiful thing. :D
 
#29 ·
The manual trans in the E39 has been know to last well passed a quarter million miles w/o any issues. I'm willing to bet in 10 years the e60 M5's with manual trans will be more desirable than the smg counterparts.
 
#30 ·
As these cars get older, I expect the independents and aftermarket will have sorted out a lot of the repair headaches. This will be fueled by budget conscious owners who will push the independents and aftermarket companies to find innovative repairs to keep these things on the road at relatively modest cost compared to dealer standards. Things that would have been major drama and trauma at the dealer will not be such big deals. I also expect that will probably be a fair number of M5/M6 SMGs trannies laying around at wrecking yards, and doing searches on car-part.com will turn up M5/M6 SMG trannies for $2500-3000 from reputable yards. Probably already plenty trannies and engines around from wrecked cars, and all the cars under warranty get shiny new ones at the dealer. So, do the wrecking yards think they're investing in the future by hanging on to these parts? No, they want to move them, the sooner, the better. So what if a new trans is very expensive at the dealer? Doesn't matter. The used parts are there, and either the yards get competitive to move the stuff, or they'll hang on to it longer and the prices will probably be driven down further as people are willing to pay less to keep the cars on the road. The internet is only making this better for consumers. I remember the E34 M5 was ooh ahh drama. Then The E39 was. I expect the E60 will be. Still more crap to go wrong, but nobody will be paying retail price because they blew up their engine or gearbox etc. If I had an E34 M5 again I sure wouldn't be afraid of the engine blowing, I might pick up a clean spare for a few grand just in case. Or not. Plenty of them around. Oh, and somebody said something about a manual trans in a big car. I certainly don't share that view. I'm enough of a fan of manuals to have a 6-speed manual swapped into my E38 740iL (long gone now). Whole shebang was like 8 grand, something like 5 grand was labor. The tranny? I bought it from a wrecker for $1500 shipped with a bunch of ancillary stuff. That was around 7 or 8 years ago. I'll bet I could play that game for cheaper today. But as much as I love manuals, to me, the SMG is just a manual with a robot assistant. At least my robot buddy can match revs every time and won't moneyshift. Dave
 
#31 ·
Sorry about the text hell above. There were paragraphs, I swear. :)
 
#32 ·
Hi, sorry to reply on the old thread. I just did my 2007 M6 from SMG to 6sp manual! I live in Jakarta, Indonesia. I did the mod coz my hydraulic pump failed so might as well i changed it to manual. The cost of the pump is around US$ 3,900 without installation from authorized workshop. The total cost of the mod is around US$ 6,500. I know it's more expensive but I think in the future i wont have any problem again with the pump failure. Now the car is in running condition eventhough i have a check engine error in the dash. I did a little test drive, it runs like charm & feel like original factory fitted.

According to my guy in the workshop, still need to change the code in DME from SMG to 6sp manual. So far, we havent got any clue what is the code & how to change it. The other solution, if i can find used DME & CAS control unit of 6sp manual car, to remove the check engine error.
 
#34 ·
No need for all of that silliness and expense.

The difference between the calibration tables for the 6MT to SMG is a single byte of data found in two locations in the map. You can easily flash the DME to the 6MT version using a good, working installation of WinKFP from BMW Standard Tools software.

If you're interested in tuning the DME, it can be switched that way as well while editing all the other maps.
 
#39 ·
Hasan,

Hard to say, but I'm going to guess it's a result of missing torque requests from the SMG module via PT-CAN to the DME. Most likely will be 3-4 error codes associated with the three SMG PT-CAN arbIDs being absent. The "getriebtype" parameter in the DME apparently flags the program to stop looking for/listening to PT-CAN data on those ArbIDs as well as flags the DME to monitor the additional sensors the 6MT has connected directly to it.

Coding the VO/FA is probably a must though, but easy enough.
 
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