I have a '88 300 SEL. In doing a lot of reading on this site I have noticed 1) my car has a 2nd gear start and 2) everyone seems to hate the 2nd gear start. What does it mean to start in second? Do you ever end up using first on these cars? Why is it so bad? Finally, if it is so bad, why did MB do it; they usually make fairly responsible engineering decisions? I am having no trouble with the trans (knock on wood) but I am curious. Thanks for your input.

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Eric Zacharias

'88 300 SEL
'64 Ford Falcon
'99 Infiniti QX4

My guess is it allows smoother take-offs, provides better traction on slippery ground and helps mpg.

First gear should come right along with enough pedal travel.

If it was such a good idea, why do MB 5-speed ATs have first gear start? Other manufacturers copy MB ideas. Why didn't anyone copy second gear start?

Sixto
93 300SD

Oh, I never said it was a good idea, just curious to know if anyone was aware of the logic behind the decision to make a second gear start. So, when I start my car, I start in 2nd, and then as I build speed I just go straight into third? What about when I leave my garage: I start in second, put it in reverse and then when I am out on the road put it into Drive. At that point would it be in first or second gear?

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Eric Zacharias

'88 300 SEL
'64 Ford Falcon
'99 Infiniti QX4

It all depends on how hard you push the gas pedal. Put it to the floor and you will find first gear. It's there if you need it.

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2009 CLS550 55,000
2004 ML350 144,000
2004 X5 95,000
2002 X5 165,000
1996 320S 155,000 (sold)
1991 190E 192,000 (sold)
1989 300SE 160,00 (sold)
1984 300D 210,000 owned since 85, (sold)
1984 300SD 160,000 (sold)

It will never go into first from a dead stop unless you put the shift lever in 2. You pull the lever down to 2 at a full stop and feel the transmission shift down to first. You'll get wall-climbing torque for a few feet then an abrupt shift to second.

It can go into first automatically if it senses a heavy load as you get moving, even if you don't hit the kickdown switch.

Sixto
93 300SD

I think a 2.88:1 would be an ideal ratio for a 300SEL with first gear start.

Low gear ratio would be about 10.9:1 (with ~3.8:1 first + 2.88:1) versus the ~3.47:1 + ~2.3:1 (second) making about a 7.9:1 only.

So you'd be quicker and probably have better economy as the motor won't be lugged badly getting from a dead stop not to mention drop about 500rpm on the freeway... about 2900 @ 70mph versus closer to 3500rpm @ 70mph.

Problem is 2.88:1 was only in the SDLs for the W126 (as I understand) and it'll cost a bit to get a VB converted for the ~6400rpm shift point. I have a few first gear start VBs but I need them, I see them at times. Next time I have a spare I can take it apart to compare with a second gear start to see what's up.

2.47:1 seems like it'd be too low of a cruise RPM for an M103 in a W126... not enough power to keep it going at 24-2600rpm @ 70mph. But hell, it very well could for all I know.

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I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

All European cars (of this era at least) must pass a test for certification in Switzerland whereby they must be able to pull a house trailer from a standing start on a significant grade.

Therefore, they have a first gear not really suited for anything else.

Kind of like the old "granny" gear in pickups that you never used unless you were a teenager that didn't know any better.

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Kent Christensen
Albuquerque
'07 GL320CDI, '10 CL550. '01 Porsche Boxster
Two BMW motorcycles

The second gear start in the Mercedes of the 80's was done for two reasons. The main reason was fuel mileage (and IIRC there might have been a fractional benefit for emissions), and the other reason was that first is a true stump-puller (for the reasons cited above) and in slick conditions can be tricky; starting in second allows easier control of power and less likelihood of wheelspin. As others have mentioned, first is available through the shift lever, through the kickdown switch if you floor it from rest, and on demand if there's an unusual load sensed.
To the best of my knowledge, it was only done on the larger V8s, due to their exceptional thirst and exceptional torque.

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Craig Bethune

'97 SL500, 40th anniversary edition

'04 Olds Bravada (SWMBO's)
'06 Lexus ES330
'89 560SL (sold)


SL--Anything else is just a Mercedes.
(Kudos to whoever said it first)

Just in case....there is a 4th too.

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It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein


09 Jetta TDI
1985 300D