850-M73 Steptronic M/S Shift Pattern - DIY upgrade to go with the SD TCM

[m6bigdog]

https://www.bimmerforums.com/forum/s...2#post30850402

Thanks Auraraptor,
Busily working behind the scenes!!

Instead of trying to locate the Unobtanium - 840-M62 Steptronic Trim

Also, could this inspire the +/- Manual Mode shift pattern reversal?
With the correct tools it is easy enough to simply swap the 2 pins in the connector.
E39 Late Model Steptronic and **E53 X5** has a possible replacement shift pattern +/- reversal.
Trims purchased eBay - on the way.

Stay tuned, more to follow...
**Update** - E53 X5 - is a no go - the pattern overlay is different than the E31 steptronic trim panel.
Reply #17 below: The E39 steptronic patterns are confirmed to fit the E31 Steptronic trim, either normal or reversed direction pattern are available for Manual mode shift tapping.


FYI - CAUTION on TRIM PURCHASE: Typical Cracking with E-39 trim, shown...
Looks like the console shift indicator overlay is somewhat fragile, so when you choose a surrogate console trim for eBay purchase, pay close attention to the condition of the lettering and cracking at the bottom area of the shift pattern overlay
Attached image:
1) From an E-39 console. Worst I've seen, Looks a Coke beverage - "brown gue under the overlay" was spilled in the trim and left to etch the overlay paint and aggressive cleaning cracked the plastic.
Photo taken with light shining through the overlay to illuminate the damage.
2) Another E-39 Steptronic shift pattern overlay with a typical cracking in the specific location.
I have looked at dozens of images on eBay and purchased a half a dozen of the E-39 Steptronic trims and it would seem the vast majority have this typical cracking at a minimum. Some more obvious than others...

[Auraraptor]

Yes, I didn’t want to share until I confirmed they overlapped, but they most definitely do! (at least from the E38)

Disassembly of the mechanism is very easy with only 3 (E31) or 4 (E38) small screws that hold the circuit board in place. Just be gentle as the LED light array has very small diffusers (aka disassemble it on a large flat surface so you don’t lose any tiny parts)

Note stylistically, E31 use a bar shape for the lights, while everything else uses a small circle shape (see the photo)

[m6bigdog]

Yes, I didn’t want to share until I confirmed they overlapped, but they most definitely do! (at least from the E38)

Disassembly of the mechanism is very easy with only 3 (E31) or 4 (E38) small screws that hold the circuit board in place. Just be gentle as the LED light array has very small diffusers (aka disassemble it on a large flat surface so you don’t lose any tiny parts)

Note stylistically, E31 use a bar shape for the lights, while everything else uses a small circle shape (see the photo)

Thanks for contributing to the SD TCM M/S shift pattern upgrade as it complete the last part that was unobtanium; as the 840-M62 Steptronic trim is NLA and even more rare on eBay - salvage dealers.
I've been looking for months and the last one I saw cost $250 and nothing since.
Now the upgrade with E38 & E39 parts is less than $50 and the +/- reversal is a viable option.
I picked up a reversed 2002 E39 shift pattern for $30.
I have patterns coming from other BMW series that also have the extra wide space between P-R just to see what works..

[m6bigdog]

Here you go...
SD TCM Steptronic M/S Shift Pattern with Reversed -/+ direction.
From:BMW E39 2002.

I have yet to do the install of this pattern, but is seems to be a clone of the E38 pattern only the -/+ direction is reversed.
The E53-X5 shifter pattern is a no-go.
Still unsure if I even want to reverse the shifter on my 8 as the OE pattern seems so natural.

I paid $30 for this E39 Steptronic M/S shifter trim and they are all over eBay in both sexes for $50-60.
Editing Note: There is a very faint diagonal crack in the overlay pictured here, to the left and below the plus. This is a typical observation of a used E39 overlay. Of course, some cracks in the overlay are more obvious than others and all are most visible when lit from behind
The last 840-M62 Steptronic M/S shifter trim I saw was listed on eBay in Oct.2022 for $250 and I have yet to find another one.
Also, you can't get the reversed shift pattern from an 840-M62 trim, period.
BF guys making the unobtainium available at a reasonable cost.

[Timm]

I don't find it natural - possibly from driving ancient 4-speed manual gearboxes. It's 1st to 2nd as you pull away (pull backwards) and 4th to 3rd as you de-accelerate (push forwards). The opposite makes no sense at all - and BMW agreed, with all the later models being naturally operational - they even changed the E39 during its lifetime.

I think I might swap the 840ci's direction to be the same as my 650i and keep the legend as it is, who looks at that anyway?

[m6bigdog]

I don't find it natural - possibly from driving ancient 4-speed manual gearboxes. It's 1st to 2nd as you pull away (pull backwards) and 4th to 3rd as you de-accelerate (push forwards). The opposite makes no sense at all - and BMW agreed, with all the later models being naturally operational - they even changed the E39 during its lifetime.

I think I might swap the 840ci's direction to be the same as my 650i and keep the legend as it is, who looks at that anyway?

I agree,
It would drive me crazy to own 2 cars with different Steptronic Manual mode -/+ directions.
If I was you, I would have done the Manual mode shift swap and pattern change when the 650 showed up...

[Timm]

Go on then, I've talked myself into it and bought this:

Fullscreen capture 15122022 215541.bmp.jpg

[m6bigdog]

Go on then, I've talked myself into it and bought this:

Fullscreen capture 15122022 215541.bmp.jpg

There you go, give your 8 some LOVE, make it BETTER...

[Auraraptor]

Traitors the lot of you!

Just kidding of course.

Personally my last few and remaining manuals were/are doglegs so the forward makes more sense to me. That and my daily Honda prelude is the same way too with forward/up.

Prelude ‘sport shift’:

[sofiabghome]

Rod,



Your car is not a daily driver...

Old school BMWs are all about the fun
with manual transmission.


You have spent a lot of time to make
this small...adjustment....but no matter
what it remains 2 pedal car.


Its time to swap 6spd gear box and have
some fun. You chose which part of the
gear rations to be quick 1-4 or 4-6
and diff will be subject to that.

On my 97' 840ci Auto I will start next year
S62 swap, finally after long wait... All of
the Automatic Garbage goes directly in
the Garbage...I can't stand the auto any
more specially with none Vanos.


Regards,
Anri

[m6bigdog]

Rod,
Your car is not a daily driver...
Old school BMWs are all about the fun with manual transmission.
You have spent a lot of time to make this small...adjustment....but no matter what it remains 2 pedal car.
Its time to swap 6spd gear box and have some fun. You chose which part of the gear rations to be quick 1-4 or 4-6 and diff will be subject to that.
On my 97' 840ci Auto I will start next year S62 swap, finally after long wait... All of the Automatic Garbage goes directly in the Garbage...I can't stand the auto any more specially with none Vanos.
Regards,
Anri

Anri,
It has been awhile..
An 840 with S62 swap will be a great ///M E31 and I assume you know the S62B50 only has 8 lb-ft of torque more than the M73B54 engine.
Yes, none of my BMW's are daily drivers, as the NorCal traffic is not welcoming to a performance BMW.

I to love the sport of the BMW with the manual and balanced suspension.
However, the manual is not for every engine but the balanced suspension is for every car!!

My previous 88 M6, is an example of the car that must have the engine followed by a manual, but the 5-speed was 1 gear short of perfection.
My current 91 M5, is another BMW that has a manual must engine (7200 RPM rev-limit), with a 6-speed and 3.64:1 final drive, so the S38B36 is very happy and so am I.

IMHO, the 850-M73, does not have the RPM bandwidth, 2-valve head with a 6k rev-limit, to be clutching through a 6-speed.
Also, the SD TCM upgrade for the 5HP30, 5-speed is not a small adjustment in the least as it dramatically enables the M73 engine power to respond to the throttle.
The gear shift pattern content of this post (OE or Reversed) just matches the Steptronic shift pattern to the upgraded SD TCM (M/S) installed in the 850-M73.
You will want to drive an 850-M73 with the SD TCM upgrade as the performance I get with the 3.23:1 LSD is impressive for a 4300 lb. car.
Before we start discussing fast and faster, I also have a Tesla P85D, so I know acceleration, 1 pedal driving and no E31 will ever be that!!!
Having Fun Now,
Rod...

[sofiabghome]

[QUOTE=m6bigdog;30851490]

Rod,

Never compare Tesla electrical power to combustion,
just never.

An 840 with S62 swap will be a great ///M E31 and I assume you know the S62B50 only has 8 lb-ft of torque more than the M73B54 engine.
Yes, none of my BMW's are daily drivers, as the NoCal traffic is not welcoming to a performance BMW.

I have to correct you here a bit. Having 8lb more it means nothing.
Your statement will be comparison only if the S62 does not have the Quad
Vanos

The S62 Variable timing maps are so good for heavy car that at low revs were
E31 need a punch the Cams are so advanced so that the cylinder feeling is
optimum. I have been around E39M5 for long time and even now I am rebuilding
one..for a customer. I have done a test many times...E39M5 with 1 person and
full thank of gas equals the E31 with driver only no passenger.I will blow up any
M73 in existence even if its bored and stroked to the moon at 6.0l.

My point to you is the Engine Dynamics are extremely important. Also the
additional almost 100hp plays a big roll here...at 6600rpm the S62 produces
400hp were the 2V dog is only 305...or so with chips..

When I do the swap lets do a roll race and you will be blown to see by how
much you will lose the race say from 40mph to 140mph 2.3.4.5 cars ahead
that is not because the additional 8lb-torque..its the additional hp and also the
engine dynamics, gearing.

Another example to you. Our S38B36 are rated at 265lb/tq. S54 is also rated
more or less the same at 262lb/tq. Put a passenger inside the E46M3 to equal
the weight to the E34M5 and do a pull against your clean E34M5 and you will
see the difference of how much the E46M3 will walk away on you...by a lot.
Same torque and not much more hp at only 23hp. Even if you have E34M5 3.8
with 340hp and more torque than the S54 the E46M3 will still be faster I have
done endless tests.

Again, its the engine dynamics how athletic is the engine thru the revs something
that you can never see on a dyno or BMW Catalog Data...never.

My previous 88 M6, is an example of the car that must have the engine followed by a manual, but the 5-speed was 1 gear short of perfection.
My current 91 M5, is another BMW that has a manual must engine (7200 RPM rev-limit), with a 6-speed and 3.64:1 final drive, so the S38B36 is very happy and so am I.

Gearing is magic !!! By choosing the right gearing one can win races, one
can make a car feel light, one can make fuel economy for the better etc...
The G420 with its first 4.23 ratio allows to lift the Elephant from dead stop
up to speed. Go drive E39M5 for a week and you will see what I am talking
about. With 3.15 the E39M5 feels sooo good..the car is fast as I call it first
part of the gear box which is 1-4. But with say with 3.45diff the second part 3-6
it will perform for the better. So having 6 Spd gear box one can adjust the
desired area were you want the engine to perform better.

The Automatic torque converter is good up until the T stat opens..and then
every time you sit on the traffic light and waiting for a green light the car will
get slower and slower...the nature of the Auto box, even with a cooler.

IMHO, the 850-M73, does not have the RPM bandwidth, 2-valve head with a 6k rev-limit, to be clutching through a 6-speed.
Also, the SD TCM upgrade for the 5HP30, 5-speed is not a small adjustment in the least as it dramatically enables the M73 engine power to respond to the throttle.
The gear shift pattern content of this post (OE or Reversed) just matches the Steptronic shift pattern to the upgraded SD TCM (M/S) installed in the 850-M73.
You will want to drive an 850-M73 with the SD TCM upgrade as the performance I get with the 3.23:1 LSD is impressive for a 4300 lb.

Gearing gearing gearing... 5HP-30 1st gear is 3.55, 2nd gear is 2.24. The Gap
is so big that you will lose HP via the wider gaps. G420 1st is 4.23 2nd is 2.53 and the
upper gears the RPM drop will be less and less, means that the engine
will stay close to pick HP.


Again, go drive an E39M5 for several days and you will see all of these
Engineering details...then park next to your E31 hop and go test drive it...it will
drive exactly like a car from 96...


The downside on S62 is that is extremely expensive!!! Used engines with 250k
sell for minimum of $7k+...and then you need another $5-6k in parts to refresh
because the S62 parts are extreme expensive....Variable timing need absolute
overhaul, chain guides list goes on and on.....

In respect to the M73/M70 the engine is like maintaining M20, 20 bucks here
10bucks there....the parts price on the M7X engine is like M10/M20 and they
are bullet proof engines. My M62 is also very very low maintenance engine,
but reading the BMW introduction of the M62 it has been design with this in
mind.

S62 is 100000000% Exotic. In your situation were the M73 is running well
its hard to make a change to S62....but it all depends how cray one is. In
my case I always wanted E31 with S62 and altho my M62 is absolute perfect
running its going out.

Regards
Anri

[Auraraptor]

I wish someone made viable upgrade cams let alone 4v heads for the M73

[m6bigdog]

Anri,
I know you know BMW's and anyone that has driven an 850-M70 know it was a disappointment.
I also know, the 850-M73 can be a disappointment with the Manual Mode Steptronic, 2nd gear take-off and no factory option for sport suspension.
FWIW, I drove several 850CSi before I purchased the 97 850-M73 and while I like a manual (driving them for 50 yrs) the 2-Valve V12 is not the engine for a 6-speed; not after a S38...
However, the 850-M73 with 5HP30, 5-speed, SD TCM, and 3.23:1 LSD final drive is a totally different E31 and IMHO, the E31 BMW should have built day-one and I anticipate would have been too much competition for the CSi.
Sorry, I don't want a manual behind the M73 (dual clutch gear box maybe).
IMHO, the S62 is great for the E39 and an engine transplant the underpowered 840 could use. I drove an 98,740i, Factory SLS and upgraded to Sport suspension and 3.38:1 final drive, for 17 yrs/175k mi. So I know the M62 like the back of my hand.
I can't tell you to go drive a 850-M73 because with only 323 examples in the US, I doubt you would find one available and even then, it would not have the SD TCM, 3.23:1 LSD, balanced sport suspension and big brake upgrades.

Anyway, I also know performance and an engine is only part of the driving experience and most cars have an unbalanced suspension and/or insufficient brakes so even if it wins the drag race it can't get around the next corner.
I have participated in many BMW club drive events over the years and there are alway guys with a V8 M3 and/or E39 M5 that think they have the ultimate road car until they see this E31 they can't catch or out run!!
An 850-M73 with appropriate upgrades is not an ///M car but that doesn't mean it is lacking performance as with a stock 850-M70 and 840-M62..
I wouldn't trade my 850-M73 for any other E31, S62B50/6-speed included, save maybe an Alpina B5.7, but, I have yet to come to terms with the cost or drive one either, so who knows.
Maybe the Tesla Model S Plaid is the next vehicle upgrade!!
We shall see...

[m6bigdog]

I wish someone made viable upgrade cams let alone 4v heads for the M73

That is what the N73B60 is for.
I think someone was attempting the transplant, the operative is attempting!!
They went dark!!

[Auraraptor]

TBH, my dream project is swapping a modern DCT with an independent controller. That way you get the benefit of the lower gears, lightning fast shifts, and lower drivetrain loss, but still have a great cruising RPM. If I ever finish my other projects, I may still try….

[m6bigdog]

Well here it is - Drum Roll........

EVERYTHING EVERYONE ALWAYS WANTED..... sounds like a movie title!

FIRST, 850-M73 TCM with Sport mode. YES!!!
AND NOW, reversed Manual mode shift tapping. This also applies to the 840 Steptronic.
Not just to have it happen, but having it on the console, Steptronic shift indicator.
Without doubt, a BMW Factory Production like upgrade!!

Photos attached:
The yellow connector buried at the bottom is actually accessible with only the shifter trim removed.
Not the easiest task, however, I was able to swap pins 2 & 3 in the connector, IMHO, the only option. Details to follow if someone desires.

Thanks Auraraptor for the inspiration to complete the SD TCM upgrade.

FYI - Caution on trim purchase:
Looks like the console shift indicator overlay is somewhat fragile, so when you choose a surrogate console trim for eBay purchase, pay close attention to the condition of the lettering and cracking at the bottom area of the overlay
Attached image:
From an E39 console. Worst I've seen, Looks a Coke beverage - "brown gue under the overlay" was spilled in the trim and left to etch the overlay paint and aggressive cleaning cracked the plastic.
Photo taken with light shining through the overlay to show the damage.

[m6bigdog]

TBH, my dream project is swapping a modern DCT with an independent controller. That way you get the benefit of the lower gears, lightning fast shifts, and lower drivetrain loss, but still have a great cruising RPM. If I ever finish my other projects, I may still try….

I thought about that. Just for fun...
PCS makes trans controllers: Don't see a ZF compatible module though..
https://www.powertraincontrolsolutio...on_Controller/

I did a little investigation into the 5HP30 control requirements.
BMW Technical Training Manual ST057/98-03, would be a good start. Hard to find document though.
I would really want more control specifications from ZF...Like the ones provided to Bosch and/or whoever wrote the original production programs.
More to a reliable transmission that meets the eye..
Then you would want to build a simulator to test your programs, as on the car could be tragic!!

Unsure if the 5HP30 can be quickened like a sequential or dual clutch manuals. The valve body may not be quick enough or clutches and bands may not be able to take the sock load from shifts and the engine torque.
IMHO, if that is what you want then I suggest swapping out the 5HP30 for a something designed for what you desire, as taking the 5HP30 to another level may just shorten the lifespan considerably or make it unreliable!!
Next question, can the rear suspension take the loading from increased gear change loading??

In the mid 70's I had a Pontiac 389 cu.in, with a 1955 Oldsmobile 4-speed manual shift automatic - Fluid Coupling, B&M built - slant pan Hydromatic.
I would chirp the tires shifting 1-2, barely touching the throttle and bust engine mounts, snap diff axles, diff pinion shafts at random.
Finally, after I don't know how many engine mounts, 5 axles and a diff pinion shaft, I swapped diffs with larger lower final drive ratio; that should do!!
Then, it bent the rear leaf springs and the trans bans would snap due to the engine torque, shock load.
Sometime going much beyond factory is fun but just causes a lot of grief.

As for a modified TCM, I would suggest only using the Bosch GS9.22.1 (microprocessor control) TCM designed for the ZF 5HP30 and if you are brave, modify the shift mapping/variables in the existing Sport & Manual mode shift programs.
Be forewarned the 5HP30 transmission is extremely complex with overlap shift and hydraulic pressure adaption to control shift quality (i.e., gear shift speeds).
This makes the DME/EGS communications on the CAN Bus between DME, EGS, EKM, IC and ASC modules and EGS shift control programs extremely complex, so if you do something wrong "BOOM" the valve body or transmission could be damaged!!
All the best with this one...

[Timm]

Spurred on by Rod's brilliant work, I decided to reverse the Steptronic direction on my E31 - here's how it is done:

[m6bigdog]

A pristine upgrade Steptronic +/- or -/+ overlay is difficult to find at best.
I anticipate the E-38 would be the better opportunity to secure an overlay that is without the cracking seen in the used E39 console trims.
However, the E-38 did not deploy the steptronic -/+ reversed manual shift pattern.

It would seem the steptronic lamp separator under the overlay is the cause of the cracking.
Hence, I have purchased several and searched numerous images on eBay of the E-39 steptronic overlays and it is hard to find one that isn't or doesn't show signs of cracking.
I have yet to be successful.
If you look closely at the images of my upgraded steptronic console trim the -/+ reversed overlay is cracked slightly.

(Update 2/19/23, -/+ reversed overlay, success) It would seem the only option to secure a -/+ reversed overlay without the typical cracking is to purchase a new 2002-2003, E39 Steptronic console trim, dont ask the cost!!!
Or, purchase a used one in person and take a magnifying glass to inspect the overlay for cracking, this I have yet to do.
After purchasing 3 on ebay, I suggest abandoning this as an option (waste of money if you want a pristine example) as every one I purchased or inspect the auction image has a cracking.
However, the E53 overlay could be fitted with some effort.

(Update 2/19/23) The E-53 overlay would be a good option but the location of the indicator between P & R (sleep indicator?) has been moved. Or maybe this is of no consequence as I can't find the function for this E31 incicator.

[m6bigdog]

Anyone else upgraded to the reversed Steptronic Manual mode shift pattern? 840-M62 or 850-M73 with SD-TCM

I've done several drives and the reversed pattern obviously takes some getting use to given the many manual shifts after 17 years of the original pattern are not yet reversed in my head.

However, for the 850-M73 with an upgraded SD-TCM-2.81, that automatically shifts 1st-4th only in SD, pretty much reduces the need for activating manual mode.