Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   PeachParts Mercedes-Benz Forum > Mercedes-Benz Tech Information and Support > Diesel Discussion

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 07-19-2006, 09:31 PM
deferr's Avatar
Want a ponton!
 
Join Date: May 2004
Location: Fort Wayne, IN 46835
Posts: 167
transmission acting up

I have been tuning up my 78 300D and it's time to start worrying about the transmission. When I got the car it seemed to slam into gear (compared to my dad's buick). I knew mercedes shifted firm but it kept getting firmer. Eventually it has come to the point where 1-2 rattles your teeth, and that to shift from 2-3 and 3-4 I have to let off the accelerator for the tranny to shift. For example, on the highway today as a test I held the accelerator down to the floor accelerating up a hill in 3rd (I was merging) and the tranny would not shift til I let off the accelerator. I didn't need to keep off it just for a second til it shifted.

__________________
'78 300D 85,000 original miles drive her daily
Reply With Quote
  #2  
Old 07-19-2006, 10:06 PM
Registered User
 
Join Date: Jun 2004
Location: West of Ft. Worth. TX
Posts: 4,186
I'm not sure what the vacuum setup is for your model. Probably the first thing to do is obtain a diagram or take a look under the hood for a disconnected vacuum line.

(My experience is mostly with the W126.)
__________________
Sam

84 300SD 350K+ miles ( Blue Belle )
Reply With Quote
  #3  
Old 07-20-2006, 01:49 AM
Registered User
 
Join Date: Jul 2004
Posts: 105
a friend of mine had a 1980 given to him because the owner thought the transmission was shot (and my friend tends to collect mercedes). turned out to be a vacuum line unattached due to a worn fitting.
__________________
1984 300D "Brown (and Blue) Betty" Over 200k but the odometer isn't counting
Reply With Quote
  #4  
Old 07-20-2006, 02:02 AM
Registered User
 
Join Date: Jun 2006
Posts: 23
At least your car is nice...
__________________
http://img215.imageshack.us/img215/9...titled2oy1.jpg
1978 300D - Somewhere around 188k miles, no reverse, no a/c, no instrument lights, sunroof only works when it's really hot outside, trying it make it more road worthy....
1999 328iS - My Baby
Reply With Quote
  #5  
Old 07-20-2006, 01:04 PM
Registered User
 
Join Date: Oct 2001
Location: st paul, mn
Posts: 284
there is no vacuum control for the transmission on '78 and '79. I have a '78 and had a '79. I would get harsh shifts if transmission oil was low. have you checked that? -Andy
__________________
andy t
'78 300d
'95 volvo 850, wagon
'86 300sdl - engine out, maybe I'll have it rolling by June

whole bunch o' bicycles
Reply With Quote
  #6  
Old 07-20-2006, 01:13 PM
Gary F.'s Avatar
Registered User
 
Join Date: Feb 2002
Posts: 110
How long has it been since you changed out the AFT? Should be changed every 30k. The transmission is the most neglected part of most cars and they are expensive to repair. If you do the change out yourself, it will only cost about $35.
__________________
Gary
85 300D Ivory, 202,000
Beatus exsisto Jesu, verus et Deus verus Vir
Reply With Quote
  #7  
Old 07-20-2006, 03:05 PM
deferr's Avatar
Want a ponton!
 
Join Date: May 2004
Location: Fort Wayne, IN 46835
Posts: 167
I don't think it's ever been low or leaked. I remember looking at the ATF when I bought it but don't remeber what the level was. I will double check and let everyone know.
__________________
'78 300D 85,000 original miles drive her daily

Last edited by deferr; 07-21-2006 at 08:15 AM.
Reply With Quote
  #8  
Old 07-21-2006, 08:14 AM
deferr's Avatar
Want a ponton!
 
Join Date: May 2004
Location: Fort Wayne, IN 46835
Posts: 167
I checked the fluid level and it is actually way too high. Am I supposed to check this level with the car running? With the car in gear? I just checked it with the car off when I was filling up and the fluid level was about half a scale reading high. Please Advise.

Dan
__________________
'78 300D 85,000 original miles drive her daily
Reply With Quote
  #9  
Old 07-21-2006, 08:53 AM
Registered User
 
Join Date: Jun 2004
Location: West of Ft. Worth. TX
Posts: 4,186
The fluid level for an auto transmission needs to be checked when the fluid is warm, car running in Park, and on level ground.
__________________
Sam

84 300SD 350K+ miles ( Blue Belle )
Reply With Quote
  #10  
Old 07-22-2006, 02:18 AM
deferr's Avatar
Want a ponton!
 
Join Date: May 2004
Location: Fort Wayne, IN 46835
Posts: 167
Found tranny problem

Ok so I figured out my tranny issue. I had adjusted what I thought to be the low idle adjustment but it in reality was the throttle linkage. I was only getting about half of the available throttle . This must also adjust the tranny although I'm not sure how. After setting my throttle to get full available throw my tranny shifts like a dream.

Anyone know why/how this linkage adjusts the tranny. It is the linkage that goes down the air cleaner side of the valve cover.
__________________
'78 300D 85,000 original miles drive her daily
Reply With Quote
  #11  
Old 07-22-2006, 03:06 AM
JimmyL's Avatar
Rogue T Intolerant!!!
 
Join Date: May 2004
Location: Sunnyvale, Texas (DFW)
Posts: 9,675
Quote:
Originally Posted by deferr
Ok so I figured out my tranny issue. I had adjusted what I thought to be the low idle adjustment but it in reality was the throttle linkage. I was only getting about half of the available throttle . This must also adjust the tranny although I'm not sure how. After setting my throttle to get full available throw my tranny shifts like a dream.

Anyone know why/how this linkage adjusts the tranny. It is the linkage that goes down the air cleaner side of the valve cover.

Pics would be nice of what you adjusted, and also of the IP side.
__________________
Jimmy L.
'05 Acura TL 6MT
2001 ML430 My Spare

Gone:
'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
Reply With Quote
  #12  
Old 07-22-2006, 10:41 AM
deferr's Avatar
Want a ponton!
 
Join Date: May 2004
Location: Fort Wayne, IN 46835
Posts: 167
will post pictures this after noon
__________________
'78 300D 85,000 original miles drive her daily
Reply With Quote
  #13  
Old 07-22-2006, 11:08 AM
Gary F.'s Avatar
Registered User
 
Join Date: Feb 2002
Posts: 110
An over filled transmission is not good, it causes the fluid to foam. Siphon off excess fluid thru the filler tube with 3/8 od tube, and check again.
I drain the trans. every third oil change, and add new fluid, costs about $8. in ATF, but it well worth it and is easy since you are under the car anyway, and it is cheap insurance, beats a $2000 rebuild.
__________________
Gary
85 300D Ivory, 202,000
Beatus exsisto Jesu, verus et Deus verus Vir
Reply With Quote
  #14  
Old 07-22-2006, 11:36 AM
Steve Bean
Guest
 
Posts: n/a
Do you have an owner's manual for this car ? It's worth reading.
Reply With Quote
  #15  
Old 07-22-2006, 12:22 PM
Registered User
 
Join Date: Dec 2005
Location: Los Angeles, CA
Posts: 340
Quote:
Originally Posted by deferr
Ok so I figured out my tranny issue. I had adjusted what I thought to be the low idle adjustment but it in reality was the throttle linkage. I was only getting about half of the available throttle . This must also adjust the tranny although I'm not sure how. After setting my throttle to get full available throw my tranny shifts like a dream.

Anyone know why/how this linkage adjusts the tranny. It is the linkage that goes down the air cleaner side of the valve cover.
On your car and mine the throttle linkage is linked to the tranny,this is why adjustment is important. we do not have vacuum controls on our trannys.

__________________
1979 300D.
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -4. The time now is 04:21 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2024 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page