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  #1  
Old 01-05-2010, 02:16 PM
okyoureabeast's Avatar
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Is my car shifting correctly?

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?
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Going back to the original post: "Can you get the vac to blow instead?" No. Vacuums are low pressure so they by nature "suck" and nature abhors them.
1984 380SL
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  #2  
Old 01-05-2010, 05:53 PM
compress ignite's Avatar
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Reading list (Not in order of Execution)

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:
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  #3  
Old 01-05-2010, 06:02 PM
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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.
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1985 300TD Turbo Euro-wagon
1979 280CE 225,200 miles
1985 300D Turbo 264,000 miles
1976 240D 190,000 miles
1979 300TD 220,000

GONE but not forgotten
1976 300D 195,300 miles
1983 300D Turbo 175,000 miles

http://i42.photobucket.com/albums/e3...e485-1-2-1.jpg
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  #4  
Old 01-05-2010, 11:23 PM
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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?
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Quote:
Originally Posted by Yak View Post
Going back to the original post: "Can you get the vac to blow instead?" No. Vacuums are low pressure so they by nature "suck" and nature abhors them.
1984 380SL

Last edited by okyoureabeast; 01-06-2010 at 01:18 PM.
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  #5  
Old 01-05-2010, 11:27 PM
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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.
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1985 300TD Turbo Euro-wagon
1979 280CE 225,200 miles
1985 300D Turbo 264,000 miles
1976 240D 190,000 miles
1979 300TD 220,000

GONE but not forgotten
1976 300D 195,300 miles
1983 300D Turbo 175,000 miles

http://i42.photobucket.com/albums/e3...e485-1-2-1.jpg
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  #6  
Old 01-05-2010, 11:32 PM
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Quote:
Originally Posted by 79Mercy View Post
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.
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Quote:
Originally Posted by Yak View Post
Going back to the original post: "Can you get the vac to blow instead?" No. Vacuums are low pressure so they by nature "suck" and nature abhors them.
1984 380SL
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  #7  
Old 01-05-2010, 11:33 PM
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did you notice any change a tall when you adjusted it the first time?
__________________
1985 300TD Turbo Euro-wagon
1979 280CE 225,200 miles
1985 300D Turbo 264,000 miles
1976 240D 190,000 miles
1979 300TD 220,000

GONE but not forgotten
1976 300D 195,300 miles
1983 300D Turbo 175,000 miles

http://i42.photobucket.com/albums/e3...e485-1-2-1.jpg
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  #8  
Old 01-05-2010, 11:41 PM
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Quote:
Originally Posted by 79Mercy View Post
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.
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Quote:
Originally Posted by Yak View Post
Going back to the original post: "Can you get the vac to blow instead?" No. Vacuums are low pressure so they by nature "suck" and nature abhors them.
1984 380SL
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  #9  
Old 01-05-2010, 11:45 PM
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ok let us know how it goes, but you will also probably have to adjust the vacuum modulator to get the firmer shifts.
__________________
1985 300TD Turbo Euro-wagon
1979 280CE 225,200 miles
1985 300D Turbo 264,000 miles
1976 240D 190,000 miles
1979 300TD 220,000

GONE but not forgotten
1976 300D 195,300 miles
1983 300D Turbo 175,000 miles

http://i42.photobucket.com/albums/e3...e485-1-2-1.jpg
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  #10  
Old 01-06-2010, 12:07 AM
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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.
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2001 ML430 My Spare

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'95 E300 188K "Batmobile" Texas Unfriendly Black
'85 300TD 235K "The Wagon" Texas Friendly White
'80 240D 154K "China" Scar engine installed
'81 300TD 240K "Smash"
'80 240D 230K "The Squash"
'81 240D 293K"Scar" Rear ended harder than Elton John
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  #11  
Old 01-06-2010, 12:16 AM
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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.
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  #12  
Old 01-06-2010, 11:25 AM
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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?
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Quote:
Originally Posted by Yak View Post
Going back to the original post: "Can you get the vac to blow instead?" No. Vacuums are low pressure so they by nature "suck" and nature abhors them.
1984 380SL
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  #13  
Old 01-06-2010, 11:58 AM
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Quote:
Originally Posted by okyoureabeast View Post
Jimmy, you make absolutely no sense.
Oh, Jimmy, Jimmy. This quote is SO full of opportunity...
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  #14  
Old 01-06-2010, 01:10 PM
okyoureabeast's Avatar
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Quote:
Originally Posted by MBeige View Post
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.
__________________
Quote:
Originally Posted by Yak View Post
Going back to the original post: "Can you get the vac to blow instead?" No. Vacuums are low pressure so they by nature "suck" and nature abhors them.
1984 380SL

Last edited by okyoureabeast; 01-06-2010 at 01:33 PM.
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  #15  
Old 01-06-2010, 03:14 PM
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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.
__________________
1985 300TD Turbo Euro-wagon
1979 280CE 225,200 miles
1985 300D Turbo 264,000 miles
1976 240D 190,000 miles
1979 300TD 220,000

GONE but not forgotten
1976 300D 195,300 miles
1983 300D Turbo 175,000 miles

http://i42.photobucket.com/albums/e3...e485-1-2-1.jpg
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