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View Poll Results: Does your 722.3 ('81-85) start in first or second gear?
Transmission always starts in first gear 40 78.43%
Transmission starts in second gear unless pedal is mashed........then it drops to first 11 21.57%
Voters: 51. You may not vote on this poll

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  #46  
Old 12-16-2009, 12:23 PM
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both of mine start in 2nd and drop to first when accel. from the stop

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  #47  
Old 12-16-2009, 01:51 PM
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Quote:
Originally Posted by funola View Post
Unless I have it wrong but it is a 4 spd automatic? 1st shift engages 2nd gear, 2nd shift engages 3rd gear, 3rd shift engages 4th gear. All the shifts were upshifts. What other gear could it have started from other than 1st?
If the transmission started in second gear, then the downshift to first gear was so smooth and fast that it was not detectable, how would you know that it did not occur?

Is there at least some take-up on your Bowden cable? If it is not properly adjusted, you cannot expect that your transmission will shift as designed.

Does your transmission downshift to first when coasting to a stop? If not, when does it downshift? (If you aren't sure, compare it in D versus 2/L. In 2/L, it should downshift all the way to first when slowing to a stop.)

Last edited by tangofox007; 12-16-2009 at 02:05 PM.
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  #48  
Old 12-16-2009, 02:14 PM
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Quote:
Originally Posted by tangofox007 View Post
If the transmission started in second gear, then the downshift to first gear was so smooth and fast that it was not detectable, how would you know that it did not occur?

Is there at least some take-up on your Bowden cable? If it is not properly adjusted, you cannot expect that your transmission will shift as designed.
To be honest, I don't know if my Bowden cable is adjusted properly. I should be able to tell what gear I'm in by what's indicated on the speedo and tach and gear ratio. If it started in 2nd and then in a micro second imperceptably shifted into 1st before the car even moves then for all practical purposes it started in 1st. Tell me how the transmission in my 83 300D is designed and supposed to operate.
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  #49  
Old 12-16-2009, 09:40 PM
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Quote:
Originally Posted by Brian Carlton View Post
To honestly confirm a first or second gear start, it would be necessary to start downhill with no throttle. At about 10 mph, downshift to first and see if you get a 2-1.

The theory is that the slightest touch of throttle causes the 2-1 and you cannot feel the shift.
I'll look for an opportunity to try the test that way.

HOWEVER, I have a question.

If you're sitting dead stopped, and it really IS in 2nd gear, but the slightest touch of throttle causes it to downshift to 1st gear, are you really starting out in 2nd?

Seems to me that you are in fact sitting still in 2nd and actually starting (i.e. starting to move) in 1st...

...and if that is the case, what difference does it make that it was in 2nd before you started to move?
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  #50  
Old 12-16-2009, 10:03 PM
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Quote:
Originally Posted by rcounts View Post

...and if that is the case, what difference does it make that it was in 2nd before you started to move?
It's just a technical point that TF and I are trying to prove or disprove.

He's convinced that the vehicle sits at a dead stop in second gear.

I had my doubts............but will do some tests to confirm or deny his hypothesis.............a hypothesis that is stated in the FSM by the way.
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  #51  
Old 12-16-2009, 10:14 PM
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Quote:
Originally Posted by rcounts View Post

HOWEVER, I have a question.

If you're sitting dead stopped, and it really IS in 2nd gear, but the slightest touch of throttle causes it to downshift to 1st gear, are you really starting out in 2nd?
Yes. If the shift sequence is 2-1-2-3-4, you were absolutely starting in second.

Quote:
Originally Posted by rcounts View Post
...what difference does it make that it was in 2nd before you started to move?
If you don't care about how things work, it makes absolutely no difference whatsoever. If an understanding of automatic transmissions was critical to vehicle operation, there would be darn few drivers on the road.

In a recent related thread, a member believed his transmission was not upshifting into 4th. Once he better understood the operation of the transmission, he was able to properly conclude that the actual problem was that it was not downshifting into 1st.

Last edited by tangofox007; 12-16-2009 at 10:26 PM.
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  #52  
Old 12-16-2009, 10:37 PM
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I've seen lots of references to the tranny starting in second too, but as far as I've been able to determine, mine doesn't, and since I wouldn't want it to, I have always been happy about it NOT starting in second.

As for "caring" about how things work - sure I do. If your definition of starting in second means the transmission being in second gear to begin with, then sure, maybe it "starts out" in second gear. But if your definition of "starting" in second gear means when it begins moving the transmission is trying to move the car while it is in second gear, then it doesn't "start" (moving) in second gear. A true case of semanitcs in the sense that it depends on what you mean by "start" or "starting".

Knowing that it sits idling in second until it starts to move and then instantly shifts to first is an interesting fact, if true, but makes no functional difference in driving the car or how it accelerates or performs. I can only think of one potential benefit from having it sit in second while idling in gear and that would be if the internal pump would be turning faster and therefore providing more oil circulation and therefore better cooling and lubrication.

I just thought of another way to test it. On flat level ground, if I am idling in gear and just let off the brakes my car will attain a speed upwards of 5 mph without even touching the throttle. If it is "starting" in second gear, and I let it get up to max speed at idle - without touching the throttle - and then I drop the shift lever into first, it would have to downshift to first if it is in second, right? I'll try that tomorrow.

And I'd modify your statement that...
Quote:
If understanding automatic transmissions was critical to vehicle operation, there would be darn few cars on the road
...to say "If understanding automatic transmissions was critical to vehicle operation, there would be darn few cars with automatics on the road."

On the other hand, my dad always said that "unless you understand how one works, you can't really properly operate a clutch to make it last as long as possible"...
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  #53  
Old 12-16-2009, 10:53 PM
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Quote:
Originally Posted by rcounts View Post

I just thought of another way to test it. On flat level ground, if I am idling in gear and just let off the brakes my car will attain a speed upwards of 5 mph without even touching the throttle. If it is "starting" in second gear, and I let it get up to max speed at idle - without touching the throttle - and then I drop the shift lever into first, it would have to downshift to first if it is in second, right? I'll try that tomorrow.
Don't let it get too fast, or it won't downshift to 1st immediately. Below about 10 mph should be okay.

Quote:
Originally Posted by rcounts View Post
A true case of semanitcs in the sense that it depends on what you mean by "start" or "starting".
The MB 722.3/4 operating manual uses the term "moving off" to describe the process known in my last job as "getting underway."

Here is a quote:

With the vehicle stopped, the engine running and idle throttle the transmission will shift to second speed upon engaging driving positions D or 3.

- When moving off with little gas the 2nd speed remains engaged.
- When moving off with much gas a downshift to first speed follows.
(emphasis added)

Last edited by tangofox007; 12-16-2009 at 11:16 PM.
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  #54  
Old 12-18-2009, 09:17 PM
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Quote:
Originally Posted by kerry View Post
Off topic, but the W116 300d will only downshift into 1st if you come to a complete and absolute stop. Some kind of pendulum switch somewhere initiates the downshift. But once stopped, it starts in 1st.
well if you have a w116 300d, then it's a one-off model.

my w123 300d starts in first. trust me, i followed tangofox's guide and it does
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  #55  
Old 02-13-2010, 03:17 PM
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Quote:
Originally Posted by Brian Carlton View Post
See, here I go and get you the data...........and you decline to accept it.........calling the intelligence and capability of the poster into question..........

I'll do some experiments with the SD and see if I can confirm your thesis on this matter.

I have completed my research and here are my findings:


1) If the Bowden cable is disconnected, the vehicle always starts in second gear.

2) If the vehicle is moving very slowly in traffic (about 3 mph) with the driver's foot off the pedal, and the pedal is pressed ever so slightly........just enough to move the linkage to the Bowden cable, but not enough to open the rack........a very slight bump is observed and the vehicle will accelerate ever so slightly.

3) If the vehicle is moving slowly in traffic (about 5-6 mph) with the driver's foot off the pedal, and the pedal is pressed ever so slightly.........just enough to move the linkage to the Bowden cable but not enough to open the rack........a very slight bump is observed and the vehicle will decelerate ever so slightly. It's actually somewhat disconcerting until you realize that the engine had to increase in speed due to the 2-1 downshift, and that speed increase slowed the vehicle.


Therefore is it concluded, with certainty, that the 617 turbo will rest in second gear until the pedal is pressed.......very slightly........when it immediately downshifts to first.

I was originally mistaken as must be the majority of those polled. TF is correct in his statements and analysis.

Last edited by Brian Carlton; 02-13-2010 at 10:15 PM.
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  #56  
Old 02-13-2010, 06:56 PM
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I'm glad this thread was resurrected. I forgot to post back with my results. As it turns out, mine DOES start in second gear - IF you don't touch the accelerator. I tested it several times.

In a flat parking lot, shift lever in D, from a dead stop, lift my foot off the brake pedal. Let the car get up to a little over 5 mph, shift the lever down to 1st, and it downshifts. Every time, without fail.

If I even press my foot on the accelerator and move it even enough to take the tiny bit of slack out of the linkages, THEN shift the lever to 1st gear, nothing happens - it has already down shifted to first gear.

So, I would have to agree with your conclusions, Brian. As long as the accelerator/bowden cable doesn't move, the tranny stays in second gear unless shifted down via the shift lever. ANY movement of the accelerator/bowden cable and it instantly down shifts to first. I also want to comment on the fact that when it down shifts, it does it so quickly and smoothly that it is undetectable.
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1984 300 Coupe TurboDiesel
Silver blue paint over navy blue interior
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~210k miles on the clock

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Charcoal & blue two tone paint over burgundy interior
Banks turbo, DRW, ZF-5 & SMF conversion
152k on the clock - actual mileage unknown
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  #57  
Old 02-14-2010, 11:21 AM
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Originally Posted by rcounts View Post
ANY movement of the accelerator/bowden cable and it instantly down shifts to first. I also want to comment on the fact that when it down shifts, it does it so quickly and smoothly that it is undetectable.
I must disagree with "undetectable". With very small application of the pedal, it's quite noticeable. However, is would only be noticeable if you were seeking it out on a deserted road..........or stuck in NYC bumper to bumper traffic.
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  #58  
Old 02-14-2010, 04:20 PM
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So how much slack should there be in the Bowden cable?
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  #59  
Old 02-14-2010, 04:41 PM
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Originally Posted by BHutch View Post
So how much slack should there be in the Bowden cable?
There should be no "slack" in it. The slightest movement of the linkage should move the cable........and you'll notice that the cable moves before the rack moves.
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  #60  
Old 02-14-2010, 04:46 PM
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Thanks, that's what I thought.

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