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  #1  
Old 12-02-2008, 03:11 PM
Provo Spain?
 
Join Date: Nov 2001
Posts: 656
Transmission oddities

1994 c280, 722.4 transmission. 128k miles, serviced regularly. The transmission won't let go of second gear (even after warm up, which works correctly btw) all the time. Often it will hold until 3500-4500 rpms before it shifts. If I bring it up to 2500-3500 rpm and let off the throttle it will shift (like driving a stick.) If I go really light on the gas pedal sometimes it will shift as it should. Vacuum leaks have been addressed, and there was no metal in the pan the last time I dropped it. From what I've read, this sounds like the governor is sticking.(I've searched and read posts about cars that won't shift at all out of second, but nothing like my issue. ) Any ideas? It hasn't gotten worse, but it certainly isn't getting better on it's own. Although one afternoon it shifted flawlessly for three stops lights, lol.


I want to be clear that I'm not talking about the car holding gear when it's cold. In this case, it simply will hold the gear all the time.

Thanks.

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1994 C 280 117.5k, White (Good as new)
1997 Toyota Camry 149k Miles (Not so pretty anymore)

1990 190e 2.6 95k (Sold-Should not have)
1981 240d Stick ??? Miles...sold
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  #2  
Old 12-02-2008, 06:38 PM
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Join Date: Nov 2006
Location: jersey
Posts: 188
if you pop off the small boot on the modulator ( the key adjustment area ) and trans fluid is present than the vacuum signal is being affected - the day it worked it might have gulped the oil out of the line for a few minuets - check it out - jz
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  #3  
Old 12-02-2008, 11:58 PM
Provo Spain?
 
Join Date: Nov 2001
Posts: 656
Quote:
Originally Posted by johnjzjz View Post
if you pop off the small boot on the modulator ( the key adjustment area )
Is this on the side of the transmission? Thanks.

Edit: Also can a faulty MAF cause shifting issues?
__________________
1994 C 280 117.5k, White (Good as new)
1997 Toyota Camry 149k Miles (Not so pretty anymore)

1990 190e 2.6 95k (Sold-Should not have)
1981 240d Stick ??? Miles...sold

Last edited by Jason Beal; 12-03-2008 at 05:48 AM.
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  #4  
Old 12-04-2008, 06:43 PM
Provo Spain?
 
Join Date: Nov 2001
Posts: 656
Does this transmission have the k1 spring problem that causes the 2-3 shift issue? Anybody know?

I cleaned the MAF last night and it smoothed out my idle (curious to see if it helps with my gas MPG) but did nothing for the shifting issue. Adjusted the modulator on the side of the trannie and while that firmed up my shift I still have second gear holding before it shifts.
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1994 C 280 117.5k, White (Good as new)
1997 Toyota Camry 149k Miles (Not so pretty anymore)

1990 190e 2.6 95k (Sold-Should not have)
1981 240d Stick ??? Miles...sold
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  #5  
Old 12-04-2008, 06:53 PM
compress ignite's Avatar
Drone aspiring to Serfdom
 
Join Date: Feb 2004
Location: 32(degrees) North by 81(degrees) West
Posts: 5,554
Tranny

JB,

I HIGHLY recommend these three Posts/Articles:

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

http://peterschmidtransmission.com/

http://www.continentalimports.com/ser_ic20242.html

Further thought:Kickdown switch underneath the Accelerator Pedal might be bad.

And yes it has the K-1 (Along with half the rest of the Alphabet.)

I'm not as "up" on the Transmission as I should be...

If you can interface with STEVEBFL he may be able to assist you further.
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  #6  
Old 12-07-2008, 07:15 AM
hey_allen's Avatar
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Join Date: May 2006
Location: Tacoma, WA
Posts: 728
If you get to feeling like really diving into the deep end of the transmission troubleshooting and want the rebuild manual, you can get it from ATSG.com for $25.

If you opt to buy the paper copy, you'll still get access to download the electronic version so you can play with it on your computer while you wait for the dead-tree version to arrive.

Happy wrenching, regardless!

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-Josh
Testing the cheap Mercedes axiom, one bolt at a time...
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