I have been missing first gear since i bought my '92 300D. I always assumed it was a issue with the valve body and would get around to fixing it some day down the road.

A month or so ago the B2 band broke (722.418 transmission) so i sent it out to be rebuilt. The valve body was cleaned out and B2 band replaced so everything should have been fine. I installed the transmission this week and i am still missing first gear. Does anyone have any theories about what the cause could be? Everything works great in the transmission with the exception of 1st gear.

thanks,
todd

Original transmission and valve body?

In 300Es with second gear start you can force first gear by moving the shift lever to position 2 while at a full stop. Does that do anything in your car?

If you can do so safely and without getting in trouble, mash the pedal from a dead stop. The 1-2 shift with the tach at 4800rpm should occur just under 40mph. The 2-3 shift occurs just under 60mph. Your car might have different shift rpms.

Sixto
87 300D

I have found no way to force a 1st gear start starting in 2nd. As far as i know the 722.418 should always start in 1st. A friend has a 1991 300D and does not have these symptoms at all.

The shift points at max RPM definitely show a missing first gear. It does not shift at the first dot on the speedometer and shifts exactly on the second set of shift dots.

It is the original transmission and valve body, although it was just completely rebuilt.

-todd

Your rebuilder owes you some money.

Sixto
87 300D

So there is little or no chance it would be anything outside of the valve body (shift linkage adjustment, vacuum issues...)?

Possibly the pressure control (Bowden) cable is too slack. I don't know where the adjustment point is in a 2.5. Follow the cable up the passenger side bell housing to where it attaches to the throttle linkage. There'll be a threaded collar and plastic nut on the ferrule where the cable emerges from its sheath. The basic adjustment is just slack with the throttle linkage in the idle position. Try setting it with some tension which will delay shifts. Vacuum and shift linkage adjustment don't have anything to do with it.

Sixto
87 300D

I have tried a few other things with my transmission and still no luck getting 1st gear.

- Tested the kickdown solenoid in the trans to verify i was getting 12v. I did see 12v when pushing on the kickdown switch under the accelerator.
- I did apply 12v directly to the solenoid and did hear it move.
- Disconnected the boden cable and tried driving. The car will not kickdown when floored without the cable connected, although a '92 300D that has first gear shows the same behavior.

The transmission was tested on the bench to be fine with a working 1st gear, however when it went back in the car 1st gear is still missing. I do have a number of electrical issues with the car and trying to figure out if this could be something electrical or something in the valve body causing my 1st gear problems.

Any more opinions on possible causes of this or should i be dropping the valve body?

thanks,
todd

On the Transmissions on my 84 300d the B2 Piston pushes on a Pin. The Pin comes in different lengths. There is a Measurement you make with a Vernier Caliper (Valve Body off) to see if you have the correct sized Pin.

I do not know if the thread was in our Forum or Benzworld but someone said that applied pressurized (with the Valve Body off) to one of the passages to actuate the B2 Piston (so He could see if it moved or not).

Has the B2 Piston and the Seal and Bushing that is behind the Seal been inspected. Maybe someone put something in wrong or?.

__________________
84 300D, 82 Volvo 244Gl Diesel

if you are near NC, I am stripping a 93 that has a broken timing chain, but otherwise sound...

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

I wish i was near NC, I'd be over helping this weekend.

I think my problem lies in the valve body and I think i would rather rebuild a spare rather than messing with mine that works fine with the exception of first gear.

With the shift lever in 2 from a full stop, how fast is the car going at 4000 rpm?

Sixto
87 300D

From a dead stop with shift lever in 2 and the accelerator to the floor 4,000 rpm is right around 42mph without shifting.

40 mph at 4000 rpm sure sounds like first gear to me. Second gear at 4000 rpm will have you at freeway speed. Or your torque converter is slipping like crazy.

What you might have is an instantaneous 2-3 and 3-4 shift making it seem like you're missing a gear. My car does that if I keep the revs at or below 2000 rpm.

Sixto
87 300D

HERE:

W124 First gear start and Transmisson question

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'84 300SD sold
124.128

agreed - my car being an E300D - has the same behaviour, with extremely soft pedal application the transmission does the 1-2 shift instantaneously - and no amount of pedal would kick it down to 1st - the only way it will extend first to max engine speed is if I floor it on take-off.

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1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)