Does anyone know if a 1980 300D has a 1st or 2nd gear takeoff (722.118)? My car will start off in 1st gear, but sometimes when the transmission is warm and I barely press the accelerator I can get it to take off in 2nd, which I prefer. If it does start in first it will skip second and go to third gear. If the car is supposed to take off in 2nd is there an explanation as to why it will kickdown into first? When I am at a stop the car is in 2nd and will switch to first once I take my foot off the brake and hit the accelerator. My kickdown switch works fine when I intentionally press it. No local mechanic has any idea what's going on!

i would check the modulator function/adjustment.

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1973 280 - Current Project Car
1979 240d - 100% Stock
1982 380sl - 100% Stock
1985 190e 2.3 - Heavily Modified

My '83 is 1st gear start. I think it would be pretty sluggish staring in sencond gear, esp. without a turbo. Just my $.02

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1989 300E 144K

I have the 1980 300D. I do not seem to have that happenning.
Had this car close to 23 years.

But I can tell you that the 1980 (at least my model) does need a working
3 way switch on the valve cover to manage the vacuum to the
transmisison for correct shifting. (later models do not use these valves for that purpose).

With a working vac modulator and not-leaking switch I get smooth starts and shifts.
First to second to third.

I live in generally flat country, and I do travel over hills and mountains.
When my switch was bad I always felt the trans was doing the same thing
a K1 spring kit problem would do, rev up and not shift unless I backed off the
throttle and forced a shift to a higher gear.

So, the basic questions: how many miles on your car, how long have you
had it, how long has it been doing this ?

As you know the diesel has no engine vacuum like a gas engine, and the trans
shifts based on vacuum signals. The vacuum in a diesel is created mechanically with a pump and used to simulate the load of a gas engine.
So, I suspect quirky vacuum problems (easy,easy, easy to solve).
If your mechanic is a gasser mechanic, he might overlook this vacuum thing.

With brake pedal pressed vacuum can drop, like a gas engine under load,
this could put you in second (like you state). When brake pedal is let go
the vacuum could jump, creating the same situation as no load in a gasser.
Maybe this explains the odd behaviour.

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80 300D 340K Owned 30 yrs
83 300SD 440K Owned 9 yrs - Daily Driver 150mi/day
02 Z71 Suburban 117,000
15 Toyota Prius 2600 miles
00 Harley Sportster 24k
09 Yamaha R6
03 Ninja 250

I have adjusted the modulator - less pressure will shift out of first, but then flair between 2nd and 3rd if it doesn't jump to 3rd and skip 2nd entirely.

I have a new 3-way valve and a new VCV so the vacuum is good and to spec. When you say your car shifts from first to second to third, do you mean from second to third to fourth since it's a four speed? That would answer my question about a second gear start, and would raise another question... why does my car kickdown to first gear off the line?

Could you explain your brake pedal/vacuum drop explanation? I'm not quite following how the brake pedal has anything to do with the vacuum. Is there an electronic mechanism that I'm not aware of? Thanks

I think models prior to 1981 had 2nd gear start.

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'81 MB 300SD, '82 MB 300D Turbo (sold/RIP), '04 Lincoln Town Car Ultimate

Sooner or later every car falls apart, ours does it later!
-German Narrator in a MB Promotion Film about the then brand new W123.

My '80 300TD starts in first.
Steve

the 80 300sd has an electronic module to give the 1st gear on takeoff.the module commonly go bad and is located in the passenger footwell just ahead of the door under the trim panel.mine had a burned trace which i repaired.made quite a difference

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michael cole 1980 300SD gone now but not forgotten,87tdt,90 300te 4matic 95 e320 wagon

According to my 79 300sd factory repair manual. When you are stopped with your foot on the brake the transmission is in second. As soon as you let the brake off, the transmission changes to first and then back to second at around 5mph under normal acceleration.
The manual says the reason for second gear while at a stop is to cut down on the car trying to creep forward.
My 300sd does exactly as described.

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Second owner 1979 300SD 250K miles.
1995 Ford Lightning
66 Mustang
87 5.0 Mustang
08 Ford Edge
46 Willys Jeep
89 Transalp
97 Dodge Ram 2500 Cummins..