Is my car shifting correctly?

[okyoureabeast]

Hey guys I have a question regarding the shifting of my 1985 300D.

I have never had the opportunity to ride in another w123 so I have no idea what proper shifting looks like. So here is what happens.

When I have my car warmed up I press on the accelerator and the RPMs go up to 2600 rpm. From there I feel from underneath a very slight shift from 1-2. After that the RPMs will stay at 2600 until I get into 4th gear and then they will continue to go up depending on speed.

I can only feel the shift between 1-2. I can't feel the shift between 2-3 and 3-4 as there is no change in RPMs or any noticeable sound.

I am going from a video from diesel giant where you can obviously count what gear he is in from the video. (http://www.youtube.com/watch?v=fcsgyPGgaxg). The car he is driving is an 85 300CD.

Why is his car shifting so much later than mine as well as having noticeable shifts?

[compress ignite]

http://www.peachparts.com/Wikka/TransVacTune

It's CRITICAL... how you set your transmission's vacuum system on your diesel MBZ...

http://www.peachparts.com/shopforum/tech-help/19841-transmission-shifting-response-vacuum-span-stevebfl-you-out-there.html#post100041

And the whole Enchilada:
Transmission:

[79Mercy]

Could you make a video of how the car shifts?

If you can't feel any of the shifts you probably need to adjust the vacuum modulator on the tranny to make the tranny shift harder. You can also adjust the bowden cable.

[okyoureabeast]

I'm going to apologize for the quality of the video. I took it on my phone and youtube ruined the quality even further.

*New video further down.*

In the video I had to turn and then I floored it up to 60 mph before I had to let off the go pedal.

*Thanks compress ignite. I'm looking into it.

Edit: The previous owner (stepdad) said the car has always shifted like that when he got it back in 91. I'm guessing there might have been some tranny work done before he got the car.

When my passenger door leaked the engine shifted like DG video. Once I fixed the leak it shifted buttery smooth again.

I know of the modulator on the bottom of the tranny, but man I love it like this. Am I destroying my transmission by not adjusting this?

[79Mercy]

Thats definally not right.

Adjust your bowden cable first and then adjust the transmission modulator.

It should rev up to about 4000-4500 before it shifts.

[okyoureabeast]

Originally Posted by 79Mercy

Thats definally not right.

Adjust your bowden cable first and then adjust the transmission modulator.

It should rev up to about 4000-4500 before it shifts.

I thought so I'll crank it up two more notches and see how it responds.

[79Mercy]

did you notice any change a tall when you adjusted it the first time?

[okyoureabeast]

Originally Posted by 79Mercy

did you notice any change a tall when you adjusted it the first time?

When I first started driving the car back in june the shifts occurred at exactly like what it is doing now.

Back in early October I realized that the throttle linkages need lubricated and I popped off all of the linkages and lubricated them up.

When I reattached them, I bumped the top of the bowden cable at the accordian like rubber connector and the car started shifting earlier at about 2200 rpm. I readjusted the cable and I was back at my previous shifting RPM range of about 2600 rpm.

In short yes I did notice a difference.

Tomorrow i'm going to pull up the hood and adjust the bowden cable up to 4500 rpm. I'll report back with what happens.

[79Mercy]

ok let us know how it goes, but you will also probably have to adjust the vacuum modulator to get the firmer shifts.

[JimmyL]

Your video would have been allot more telling without the music.
85's seem to shift a whole lot smoother and more like a "real car" than other years. Allot has to do with the blue flying saucer. I know my '85 shifts perfectly so I have never ever touched anything. {it came that way}
My '81 shifts a LOT harder, and shifting is really dependent on accelerator position. It will shift quite a bit sooner with less pedal, which I'm sure is Bowden cable related. I need to soften the shifts a bit with the modulator {on back of IP, not on tranny} but have just never pried that cover off and tried adjusting it. I'm happy enough with it's operation that I haven't messed with it.
Next video you post let us just hear the car. Is your blue flying saucer still connected? You should be able to dial your shifting in to where you like it.

[MBeige]

If you are stepping the pedal ever so lightly, it will not shift late but shift early. If you floor the pedal, then it will shift late. I did not read anything that indicated either, so I thought I'd throw that in here.

Your bowden cable is probably adjusted to shift early, giving very light shifts.

If you try accelerating more spiritedly, see if you can count the shifts.

[okyoureabeast]

I will post a new video today when I go out to drive with a before and after.

Jimmy, you make absolutely no sense. Can you explain this thing?

[dadette123]

Originally Posted by okyoureabeast

Jimmy, you make absolutely no sense.

Oh, Jimmy, Jimmy. This quote is SO full of opportunity...

[okyoureabeast]

Originally Posted by MBeige

If you are stepping the pedal ever so lightly, it will not shift late but shift early. If you floor the pedal, then it will shift late. I did not read anything that indicated either, so I thought I'd throw that in here.

Your bowden cable is probably adjusted to shift early, giving very light shifts.

If you try accelerating more spiritedly, see if you can count the shifts.

Actually I have noticed that before. However if I floor it the same results occur at 2600 rpm. If I feather the accelerator it will shift at 2400 rpm, but I still cannot count the shifts.


I adjusted the cable 4 turns counter clockwise and the same shift at 2600 being completely smooth occurred. Looks like I will be reading up on this mystical vacuum modulator on the bottom of the car.

I have a pre-adjustment video that is being sent from my blackberry to my youtube account for watching. It's much better then the original video I have.

Edit: Here's the new video. I have a better version where I turn onto a clearer road. That slushing clunk noise is snow

http://www.youtube.com/watch?v=7kfgNCmG3hU

Edit 2: Ok Jimmy I understand about the blue flying saucer I need to do a little bit more reading as my 85 is a bit different from all of you other normal w123s.

[79Mercy]

Something still isn't right. Don't the 1985's have a different torque converter?

You should see a change in RPM's when changing gears. Im thinking there might be a transmission problem.