Gen2 permanent First Gear Start mod possible? - Page 2 - Mercedes-Benz Forum
LinkBack Thread Tools Display Modes
post #11 of 22 (permalink) Old 03-31-2018, 09:20 AM
BenzWorld Member
SirFerret's Avatar
Date registered: Nov 2015
Vehicle: 1987 420SEL
Location: NoVA (USA)
Posts: 137
Mentioned: 2 Post(s)
Quoted: 27 Post(s)
Originally Posted by mramay View Post
I have a Bergwerks FGS box on my 560SEC and while it's fun, it wouldn't be fun full time. I have a 3.07 limited slip diff and 245/40/18 tires on the car, and it spins the tires too easy to leave the FGS running all the time. Take off medium easy and when the revs get up just a little, the tires spin but that happens going around corners too. Probably could use better quality tires to stay hooked up longer. Highly recommend the H&R lowering springs and new front Bilsteins to keep it controllable.

My 560SEL is close to stock and even with 235/45/17 tires, it can still spin them on a first gear start. The 560 engine has a ton of torque!!

I wish my 420SEL did that haha. The car is pig even giving good throttle in 1st. It may take a while to get there, but nothing cruises like a W126 at high speed.
mramay likes this.
SirFerret is offline  
Sponsored Links
post #12 of 22 (permalink) Old 03-31-2018, 09:40 AM
Lifetime Premium Member
281lxm's Avatar
Date registered: Dec 2011
Vehicle: 1991 560 SEC 1994 E500 2014 E350 Cab
Location: Houston, TX
Posts: 7,015
Mentioned: 3 Post(s)
Quoted: 435 Post(s)
Lifetime Premium Member
So the 420 starts in first gear?

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

1991 560SEC 199 /268, 17" RS90'S, Eibach springs, Bilstein HD shocks, Custom rear sway bar, Euro Headlights, Custom ceramic coated headers and down pipes with stainless dual exhaust, W140 glass sunroof, dog ear trunk spoiler, OEM Skid Plate, Euro bumpers, wood refinish and restored.
281lxm is offline  
post #13 of 22 (permalink) Old 03-31-2018, 11:03 AM
ianrandom's Avatar
Date registered: Jul 2008
Vehicle: 1986/1990 W126
Location: Berkshire & Devon, UK
Posts: 12,920
Mentioned: 28 Post(s)
Quoted: 1171 Post(s)
Lifetime Premium Member
They all start in second I think. I know they do over here.
mramay and wooky_chew_bacca like this.

'86 420SE
'90 420SEC

Daily transport 9spd Giant DH Comp downhill bike
ianrandom is offline  
Sponsored Links
post #14 of 22 (permalink) Old 03-31-2018, 01:04 PM
BenzWorld Elite
wooky_chew_bacca's Avatar
Date registered: Oct 2009
Vehicle: '91 560SEC, '91 300SE (sold), '98 Yota, '02 S-10 Hauler
Location: Covington Ga
Posts: 8,889
Mentioned: 13 Post(s)
Quoted: 1282 Post(s)
Both of mine start in 2nd gear

Some days it's just not worth chewing through the restraints
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
My Stable:
'91 560SEC "Ursula"
'91 300SE (sold) "Sadie"
'11 Suzuki SX4 Sport Sedan
'02 S-10 Truck
'72 SeaBird boat, "Riff Raft", overhaul restarted

Dif-tor heh smusma
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
I'm surprised that NOBODY has asked me what this is / means
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
wooky_chew_bacca is offline  
post #15 of 22 (permalink) Old 04-01-2018, 01:52 PM
BenzWorld Member
Das 420's Avatar
Date registered: Jul 2013
Vehicle: 1990 420 SEL, 1990 560sel, 1991 300e
Location: Ontario, Canada
Posts: 345
Mentioned: 1 Post(s)
Quoted: 109 Post(s)
Im trying to find the hydraulic circuit diagrams for the 722.3 trans in my piles of paperwork. I have diagrams for each fluid path for each gear for the trans.

Reason I want to look at them is because, from a stop, the kick down solenoid only needs to be quickly triggered (less then 1sec), for it to command the trans into first gear, it will hold first gear and shift to 2nd based on the boden cable/throttle position. It acts like a normal trans, normally it will upshift to 2nd @ around 10-15km/h. It will hold 1st gear forever if the kick down solenoid stays continuously triggered, in my case for standard day to day driving, I only want it to quickly trigger the kick down solenoid for a short time when at a stop, then let the trans upshift as it feels.

Why does this matter?

Well the kickdown solenoid should have a direct fluid path to the 1-2 shift spool valve. And forces the valve into a commanded 1st gear. This valve should be spring loaded, thus it defaults into 2nd, unless forced. Configuring the trans to have a first gear start could be as easy as removing a shuttle spring, and possibly swapping the side it sits on.

I also have a list of which trans had 1st gear start, and which had a 2nd gear start. Ill post it up if anyone is interested.

Yes shifting into 1st might cause some aggressive starts for the majority of us due to the fact that we are used to the standard 2nd gear start, and normally give these cars a bit more throttle to get moving.
To see what a standard 1st gear start would feel like, when stopped put the selector into B (1st), then back to D. It will start from 1st gear, and shift up normally to 2nd around 10-15km/h with normal acceleration input.

560 guys might not find this of any use, but 420 cars could help slightly with a 1st gear start, I manually do it quite frequently when driving around town in stop and go traffic.
bflobob8 likes this.

In the Shop so far...
90 420SEL
90 560SEL
05 Crossfire SRT-6
02 AM General H1
Das 420 is offline  
post #16 of 22 (permalink) Old 04-02-2018, 06:02 AM
BenzWorld Extremist
gogi's Avatar
Date registered: Jan 2008
Vehicle: 1991 560sec. 1969 280SL
Location: New Jersey
Posts: 887
Mentioned: 7 Post(s)
Quoted: 235 Post(s)
I have FGS module in my 91 560sec activated by the ES switch on the trans shift surround. Personally, I prefer the normal setting as the first gear start up shift is a little harsh especially if I nail it. When I nail it, it screeches the tires on upshift to second and I feel like a boy racer lol.
mramay likes this.
gogi is offline  
post #17 of 22 (permalink) Old 04-03-2018, 01:44 PM
Premium Member
Date registered: Jun 2012
Vehicle: 1991 560 SEC Black on Grey
Location: Leesburg, Va. 20175
Posts: 1,885
Mentioned: 4 Post(s)
Quoted: 543 Post(s)
Premium Member
I do the B1 thing on occasion and wish it held first gear a bit longer but it certainly works.
bflobob8 is offline  
post #18 of 22 (permalink) Old 04-03-2018, 04:21 PM
BenzWorld Extremist
Date registered: Jun 2007
Vehicle: 1995 SL 500 2017 AMG GLC 43
Location: SouthWest Coast of Florida
Posts: 922
Mentioned: 0 Post(s)
Quoted: 65 Post(s)
Originally Posted by corellian corvette View Post
I've spent the last hour searching the forums and broader internet and was unable to get an answer to this question. I've seen people ask, but never found the answer.

I'm aware it's possible to modify Gen1 cars to have permanent first gear start by jumping pins on a specific early TCM. Totally understand how that works.

But what I've been unable to find is how to modify a Gen2 car for permanent first gear start. I have an '87 420SEL that has the B switch which enables first gear start for that specific take-off.

However, I would like full-time FGS as is possible on the older cars. I can't find any instructions on how/if that's possible. There was some suggestions to try and manually move the switch but I'm averse to doing that unless someone can confirm this won't damage the transmission.

Can anyone confirm they have done this and have any suggestions on what to do?

Lee Wireless is offline  
post #19 of 22 (permalink) Old 04-04-2018, 01:55 AM
Outstanding Contributor
mclare's Avatar
Date registered: Aug 2008
Vehicle: 2012 CL550 4MATIC Coupe
Location: Washington DC area - PAX River NAS
Posts: 9,983
Mentioned: 15 Post(s)
Quoted: 311 Post(s)
Send a message via Yahoo to mclare Send a message via Skype™ to mclare
If you read my thread "A Trek Up North", you can see exactly how and where I wired my FGS module and wired it up to a switch.

Current Stable:
2012 CL550 C4 4MATIC Coupe

Past cars:
1991-560 SEC AMG - Coupe - 199/261 - 300 HP Custom Built Motor - Highly Modified Coupe.
1990-560 SEL - Sedan - 199/261 - Stock. Euro Headlamps & Wipers
1987 560 SEC Black/Tan
1988 420 SEL Champagne/Brown

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
mclare is offline  
post #20 of 22 (permalink) Old 04-05-2018, 02:57 PM Thread Starter
BenzWorld Veteran
corellian corvette's Avatar
Date registered: Dec 2014
Vehicle: 1991 560SEC
Location: Woodinville, WA
Posts: 641
Mentioned: 3 Post(s)
Quoted: 166 Post(s)
(Thread Starter)
@mclare thanks for the advice. I first ended up reading the SECOND "Trek Up North" thread which was quite a different story!

I poured through that thread - all 100 pages. Great read, but nowhere did I see how you actually wired it up. You make mention of how you modified the switch, and you could hear the relay click, but nothing about what you actually did.

Are you sure there isn't another thread?

1991 560 SEC Euro
1986 420 SEL
1985 500 SEC (US)
1983 500 SEC (Euro)
corellian corvette is offline  
Sponsored Links

  Mercedes-Benz Forum > Mercedes-Benz Sedan Forums > W126 S,SE,SEC,SEL,SD,SDL Class

Quick Reply

Register Now

In order to be able to post messages on the Mercedes-Benz Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Title goes here

video goes here
description goes here. Read Full Story
For the best viewing experience please update your browser to Google Chrome