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-   -   Do you 'manually' shift your auto trans? (http://www.peachparts.com/shopforum/diesel-discussion/161444-do-you-manually-shift-your-auto-trans.html)

Maroon 300D 08-14-2006 11:14 AM

Do you 'manually' shift your auto trans?
 
I'm wondering because over the weekend my car began shifting from first to fourth almost immediately. I'm in fourth gear by the time I'm going 22 mph!

I did a bit of research and it seems this is a fairly common problem. Unfortunately it does not appear easy to fix. Since my kickdown switch also stopped working this weekend and adjusting the bowden cable seems to do nothing whatsoever, I'm speculating (I need to do more research still) my problem is with a certain 'governor' I've read about. It probably won't get fixed anytime soon.

This problem isn't so bad so long as I shift into 'L' or 'S' when I need to. I wonder, though, is the car designed for this? If I shift too like this too often will something break? Or can I upshift and downshift with impunity?

Anyway, I'm wondering how many other members routinely shift their car like this. If enough of you tell me you do it, too and have for years, I'll feel better about it.

Thanks!

JEREMYC 08-14-2006 11:22 AM

I manually shift mine in the morning when it is cold. I think I have some vacuum problems. It slips real bad going from 3rd to 4th when cold. My car also shifts through all gears very quickly. My transmission also "thuds" when it downshifts at slow down. I plan on checking it out real soon.

redassag00 08-14-2006 11:22 AM

I do, because its annoying to start in 2nd gear all the time.

Brian Carlton 08-14-2006 11:25 AM

I don't shift it manually with the exception of the 4-3 downshift. It won't drop 4-3 when I need it........unless floored..........so the gearshift is your friend.

You won't cause any harm with this practice.

Naturally, the shifter bushings will be worse for the wear..........

Maroon 300D 08-14-2006 11:51 AM

Quote:

Originally Posted by Brian Carlton (Post 1245834)
I don't shift it manually with the exception of the 4-3 downshift. It won't drop 4-3 when I need it........unless floored..........so the gearshift is your friend.

You won't cause any harm with this practice.

Naturally, the shifter bushings will be worse for the wear..........

Thanks, that's good to know. Without manually shifting I'm now the grandpa type who pulls in front of traffic only to drive 20 mph slower than the people behind me...

JeremyC, have you changed your fluid/filter recently? My understanding is that this can help 'cold' issues. I've got some of those too...as soon as I get moved in I'll deal with it. That reminds me, I need to to change my location...

dieseldiehard 08-14-2006 11:54 AM

Quote:

Originally Posted by Brian Carlton (Post 1245834)
I don't shift it manually with the exception of the 4-3 downshift. It won't drop 4-3 when I need it........unless floored..........so the gearshift is your friend.

You won't cause any harm with this practice.
Naturally, the shifter bushings will be worse for the wear..........

Brian, have you tried adjusting your tansmission cable? I had this "problem" after I had a new transmission installed, I was afraid it had a different performance or something until I adjusted the trans cable, I can't remember which way I turned it, actually Peter Schmidt did it, I believe he loosened it. Now it downshifts perfectly on demand.

Brian Carlton 08-14-2006 12:00 PM

Quote:

Originally Posted by dieseldiehard (Post 1245870)
Brian, have you tried adjusting your tansmission cable? I had this "problem" after I had a new transmission installed, I was afraid it had a different performance or something until I adjusted the trans cable, I can't remember which way I turned it, actually Peter Schmidt did it, I believe he loosened it. Now it downshifts perfectly on demand.

I'm sure he tightened the cable. Sure, I can do that, but the upshifts will be delayed further than I desire.

My problem is to obtain a 4-3 at about 45 mph for a freeway merge. It's not all that pleased to drop 4-3 without quite a bit of throttle pressure.

All of them exhibit this behavior so I tend to believe that it's common.

JEREMYC 08-14-2006 12:59 PM

Quote:

Originally Posted by Maroon 300D (Post 1245866)
JeremyC, have you changed your fluid/filter recently? My understanding is that this can help 'cold' issues. I've got some of those too...as soon as I get moved in I'll deal with it. That reminds me, I need to to change my location...

The service records I got with the car say it was done in 04 but it did not list the miles for some reason. I'll check out the vacuum and probably go ahead and do a fluid/filter change.

Rashakor 08-14-2006 01:28 PM

it's funny i had exactly the opposite problem with the shifting. With the 240D if i floor the pedal the car will never shift to 4th and will be screaming at 65mph. I guess i prefer that problem than the other one. also my shifts are very violent, rocking the car:confused: .

Maroon 300D 08-14-2006 01:40 PM

Quote:

Originally Posted by Rashakor (Post 1245978)
it's funny i had exactly the opposite problem with the shifting. With the 240D if i floor the pedal the car will never shift to 4th and will be screaming at 65mph. I guess i prefer that problem than the other one. also my shifts are very violent, rocking the car:confused: .

If the pedal is floored, the kickdown switch could be preventing you from shifting to fourth. Does it shift when it's not floored?

Before my car suddenly started shifting rapidly this weekend, it used to stay in third until the tranny fluid was warm. Then it would shift into fourth smoothly.

The violent shifts sound like a vac issue to me. I used to have those types of shifts when I first got the car; turned out the vac line to the modulator was disconnected! I still get some rough shifts on cool mornings, but I think that's a fluid issue.

Hatterasguy 08-14-2006 05:00 PM

More then I should, these trans never want to kick down without a fight so I just flick the lever down a gear or two. Even in the manual MB says you can do this so I don't see how it could harm it.

This should cause more wear on your shifter bushings though, but I changed all mine and enjoy the nice tight shifter feel. Maybe in 5 more years I'll spend another $20 and replace them all again.:D


I guess I shouldn't complain because they last a long time and are cheap to rebuild.:D

pawoSD 08-14-2006 05:53 PM

Quote:

Originally Posted by Hatterasguy (Post 1246172)
More then I should, these trans never want to kick down without a fight so I just flick the lever down a gear or two. Even in the manual MB says you can do this so I don't see how it could harm it.

This should cause more wear on your shifter bushings though, but I changed all mine and enjoy the nice tight shifter feel. Maybe in 5 more years I'll spend another $20 and replace them all again.:D


I guess I shouldn't complain because they last a long time and are cheap to rebuild.:D

I do it too, its fun! :D :D I love to come around a corner and drop it all the way to L, so it lunges forward with full boost, its incredible! :D :D

sailor15015 08-14-2006 07:14 PM

Quote:

Originally Posted by Brian Carlton (Post 1245834)
I don't shift it manually with the exception of the 4-3 downshift. It won't drop 4-3 when I need it........unless floored..........so the gearshift is your friend.

That's what I do. My kickdown switch doesn't work and it likes to stay in fourth longer than I like so when I slow down for a curve I just drop it down into "S" to get it to drop to third. I tightened the bowden cable and that made it better at dropping into third when I wanted but at partial throttle it would hold third a little too long before going into fourth.

Larry Delor 08-14-2006 08:06 PM

I also make it manually shift to 3rd, because it doesn't when I want it to sometimes.
I've thought about adjusting the bowden cable, but, when it is cold, it takes a tad longer than I think it should to go from 3 to 4, so I decided to leave it as it is. (well...maybe I'll try 1/2 a turn ;))

Jeremy5848 08-14-2006 08:13 PM

Me too
 
For a lot of my around-town driving, I keep the transmichigan in 3rd gear, as recommended by my indy mechanic. Although it will downshift from 4th to 3rd without the kickdown switch, I'd rather avoid the violent lunge that comes with flooring the throttle. The kickdown switch would be better it it didn't require bringing the engine to full throttle to engage it. (I guess that's what the manual downshift does for you.)

My transmission always starts in first gear from a dead stop. If I have the selector in "L," it will stay in first gear; if I then move the selector to "S," it will upshift to second and then to third and stay there. If I wait until the shift to second has been made and then move the selector back to "L," the transmission will stay in second, which is good for steep upgrades (driveways, narrow rural roads, etc.).

It's clear from the many different posts on various threads that either Mercedes changed the programming in various years of this tranny or people have vacuum and linkage problems or both.

Jeremy


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