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SMG III must maintenance/modifications for reliability + daily driving

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Looking into getting an SMG3 M5 that I can use for the occasional commute as well as road trip or back road spirited drive. Initially wanted to do a DCT swap with the Getrag box out of the E9X M3 but seeing as there are no factory-esque builds/swaps done out there (or at least well documented ones), I've lost hope in pursuing for the time being. Don't want a manual as the unoptimized gear ratios are a turn off and render paying a premium for the 3pedal a bit redundant, plus I'd want to be able to lend my parents or s/o the car to putt around town if they need it.

My question is: what maintenance/modifications/tunes/etc. are the must haves to increasing the reliability and daily driving ability of the SMG3 box. I understand SMGs are not as bad once you "learn" how to read what it is going to do next and modulate the throttle yourself for smoother shifts, but my mother is never going to learn that ;) and to be frank, I don't want to have to either. Whatever mitigation can be done to smoothen it out as well as increase reliability would be much appreciated. Thanks in advance. Photo of my 00' E39 M5 on the day I bought it below :)

P.S. If anyone has some new info on the feasibility of a DCT or some smooth automatic swap on the S85 please let know or link below. Open to spending a healthy chunk on one of those swaps assuming the dash isn't lit up like a Christmas tree (for the most part) afterwards. I find being $50-60k into an NA V10 performance sedan much more worthwhile than spending that or more on an F10/90 M5 with more unusable power and a worse sounding motor that's harder to work on. No offense S63 guys ;)


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I love my SMG III M5, depending on the known service history, if it’s lacking and you really want to refresh it I would do the following, new OEM flywheel and clutch, new clutch fork, clutch pivot pin, drop the trans and check the hydraulic system and replace the wiring harness, and fluid change, I would then install the Euro transmission tune. With parts and labor at a serious BMW indy shop, you’re probably looking at around $4,000, with that service you’d have a very smooth and well sorted SMG III. Remember in D mode it will be a bit jerky at times, manual shifting it’s great. Go big or go home…
 

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I would pay good money for ZF 8spd auto box swap for my e60 m5. That adapter plate and TCU tune package is low hanging fruit for anyone looking to make about a million dollars from members on this forum

Second option is:
Just swap it in. Have lifetime warranty on the SMG III as long as you change the clutch. The actual gearbox won't break.
 

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Just get supercharger. No need to mess with gearing ratio. That's what I got. I think sounds little better (you get the engine howl). The numbers say e60 m5 is slowest car I have in my garage but it feels the fastest thanks to constant SMG clunking and crude poundage. That's what most of us mean by "smg character". You also learn to shift it with your gas pedal. It's not as exciting as manual but it's 50% there. If you want to be a hero, i'm pretty sure there is a way to convert our 7spd smg to true manual. Shift pattern is wonky but maybe different fork or something. or one of those 'sequential' style manual shifter adapter to bolt onto our wonky pattern?
 

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Here’s my build…
My stroker is 5.8L, billet crank, Carrillo H beam rods, Mahle custom pistons, block was bored by the team at CarBahn Steve Dinan’s new shop using correct techniques to maintain the Alusil microstructure, heads were ported and polished and refurbished, performance valve springs, new correct rod and main bearings, Vanos refurbished, new throttle actuators, all other seals, hoses, etc., replaced if needed, balanced rotating mass, basically a complete rebuild, equal length headers with 200 cell race cats, sport exhaust, custom tune to max power and torque, Evolve Eventuri intake, needles to say it’s really fun to drive, also a 3.91 2 clutch pack differential by DiffsOnline, SMG with Euro tune, Bilstein B6 shocks, H&R springs, BBK kit by Stoptech, RD Sport F & R sway bars, still looking to do minor tweaks and probably go to the Bilstein B16 set up at some time, installing a RPi front oil cooler once it arrives…
 

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Just get supercharger. No need to mess with gearing ratio. That's what I got. I think sounds little better (you get the engine howl). The numbers say e60 m5 is slowest car I have in my garage but it feels the fastest thanks to constant SMG clunking and crude poundage. That's what most of us mean by "smg character". You also learn to shift it with your gas pedal. It's not as exciting as manual but it's 50% there. If you want to be a hero, i'm pretty sure there is a way to convert our 7spd smg to true manual. Shift pattern is wonky but maybe different fork or something. or one of those 'sequential' style manual shifter adapter to bolt onto our wonky pattern?
I think the more unusual issues are the independent rods in our transmissions making any traditional solution a no go. I do think there is an elegant solution to it though. I keep looking for a cheap SMG 3 on ebay to pull apart and go at it, have some ideas of my own :whistle: .
 

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Here’s my build…
My stroker is 5.8L, billet crank, Carrillo H beam rods, Mahle custom pistons, block was bored by the team at CarBahn Steve Dinan’s new shop using correct techniques to maintain the Alusil microstructure, heads were ported and polished and refurbished, performance valve springs, new correct rod and main bearings, Vanos refurbished, new throttle actuators, all other seals, hoses, etc., replaced if needed, balanced rotating mass, basically a complete rebuild, equal length headers with 200 cell race cats, sport exhaust, custom tune to max power and torque, Evolve Eventuri intake, needles to say it’s really fun to drive, also a 3.91 2 clutch pack differential by DiffsOnline, SMG with Euro tune, Bilstein B6 shocks, H&R springs, BBK kit by Stoptech, RD Sport F & R sway bars, still looking to do minor tweaks and probably go to the Bilstein B16 set up at some time, installing a RPi front oil cooler once it arrives…
sounds amazing bro. It's just different approach. Stroker kits are awesome. I just like the supercharger because I got it installed in couple weekends on my own and now the car walks hellcats. It made engine pitch higher and more crisp. Power delivery is better than stock because you gain so much mid range torque from the boost. It's all I had to do. Everything else can be 100% stock. My car now is at 170k miles (sc installed at around 110k). I just think it's the way to go. if I want more power, I just have to put in a smaller pulley. but I'm limited due to 91octane.
 

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do it!!!!!!!!!!!!
I will do my best. But first, tell me more about this supercharger. Sounds like it has been reliable for 60K? Which kit? Any internal mods? I see one in my future but I don't want to deal with anything internal right now and while I like the idea of a stroker, the risk/reward/cost and losing the kinda cool oversquare design is asking too much.
 

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ESS. yea just needs oil change whenever you do the engine oil change. Engine is 100% stock other than ACL rod bearings. I took the primary cats out. Runs like a swiss watch. They make their own supercharger now with higher power potential especially if you have 93 octane. My kit is their vt2 kit with the vortech unit.
 

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I couldn't imagine how you would convert the Getrag box to a row-your-own manual, I've split the box open and it's tight in there and what gears the forks control is all over the place. I don't really see opportunity without excessive design and machining to try to change levers control which gears as well. This was Getrag going "clean sheet" on designing a box for sequential shifting to evolve far beyond what they did with the SMGII. Pipe dream imo...

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I think this is the solution:


there are many of these H-pattern to "sequential" converter boxes. You pull back to shift up & push forward to shift down. I am 90% sure the manufacturer can modify its internal to make it work for our gearbox.
Cool solution, one problem I think is there is no external direct control of the shift rods designed into the transmission like on a traditional manual and it seems spacing is tight in there. There may not be sufficient space within the box to fit a mechanism.
I've never looked closely at an H pattern/ sequential conversion so I don't really know whats involved. Just spit balling ideas.
 

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I saw one youtube animation on how that shifter linkage worked, and I can't seem to find it at the moment. It's basically similar to true sequential where you have this groove do the shifting. Instead of having the groove on the shaft, you can have discs, cams, etc.

Here's only crap video I can find. You get the crude idea.

 
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