76 300d trans issues - Page 3 - Mercedes-Benz Forum

Reply
 
LinkBack Thread Tools Display Modes
post #21 of 36 (permalink) Old 06-06-2011, 11:18 AM Thread Starter
BenzWorld Member
 
Date registered: May 2011
Posts: 51
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
(Thread Starter)
Alright so i need to make a list of what i need to get.

For the injection pump i need a vacuum control valve.
Those missing parts for the vacuum modulator.
Vacuum line.
Doesnt seem to bad, Unless I'm missing something.
CenCalBenz is offline  
Sponsored Links
Advertisement
 
post #22 of 36 (permalink) Old 06-06-2011, 11:44 AM
BenzWorld Elite
 
Govert70227's Avatar
 
Date registered: Oct 2009
Vehicle: 2000 VW Golf Variant
Location: Leiden, Netherlands
Posts: 2,952
Mentioned: 0 Post(s)
Quoted: 4 Post(s)
Originally this transmission had a switchover valve on top of the valve cover so that the transmission would shift back to first gear at take-off, but it will work without the switchover valve too. On US cars the switchover valve is combined with the EGR control. So if you find a switchover valve from a 1980–1982 300D N/A or 240D it is even better. The VCV from any 1980-1985 240D/300D/300D Turbo can be used. Don't forget the connecting rod (nr. 3) and see if you can connect it to your diesel pump lever.

The modulator might need part number 5 too, that is the locking ring, it keeps the cap from falling off.

You need rubber "socks" too to connect the vacuum lines.
Govert70227 is offline  
post #23 of 36 (permalink) Old 06-06-2011, 03:17 PM Thread Starter
BenzWorld Member
 
Date registered: May 2011
Posts: 51
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
(Thread Starter)
where can i find the part number for the vacuum control valve and part numbers 6-9?

Can this transmission be converted back to a mechanical linkage setup? It looks like there is a hole for the lever to attach to...

It is possible to retrofit a vacuum control valve to my injection pump correct?
CenCalBenz is offline  
post #24 of 36 (permalink) Old 06-06-2011, 03:39 PM
BenzWorld Elite
 
Govert70227's Avatar
 
Date registered: Oct 2009
Vehicle: 2000 VW Golf Variant
Location: Leiden, Netherlands
Posts: 2,952
Mentioned: 0 Post(s)
Quoted: 4 Post(s)
The part numbers will be in the EPC (free for US residents). You might want to try salvage yards, because the VCV might be expensive or unobtainable new. If you have trouble I can look in the EPC for the numbers.

I doubt that the transmission can be changed to mechanical control without taking it apart to some degree. Just sticking a rod in the hole doesn't work, because there is nothing inside the transmission to connect to. The 722.118 transmission started with mechanical control, in 1980 it was changed to a vacuum-controlled transmission. MB must have changed some valves and levers inside to achieve that.

The VCV needs to be screwed to the top of the IP (two screws), but I don't know if there are screw holes available on your IP to do that. That might pose a problem, but these holes can probably be made. The other problem if whether there is a connecting piece on the IP lever for the rod to the VCV, but I think that can be retrofitted if it is not there.
Govert70227 is offline  
post #25 of 36 (permalink) Old 06-08-2011, 07:27 PM Thread Starter
BenzWorld Member
 
Date registered: May 2011
Posts: 51
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
(Thread Starter)
Ok, so i got a VCV for $10 from the junk yard. I grabed the linkage too. It looks like some retrofitting is in order.

I could not find a vacuum modulator on the '84 turbo diesel that i was pulling the parts from. I couldnt get under the car and get a good look, so i wandered around looking for a car jack in one of the adjacent cars(its surprising how hard that was to find). I then got the car jacked up aways so i could get a quick look and there was nothing under there resembling the vacuum modulator that was in the picture that was posted. Must have been a conversion. Of course i didnt get the number for the transmission type.

Its a really nice '84 too! It turns over and wants to start. They told me they will be crushing it next week. I asked how much for the turbo and was told $100! Anything else i should go back and nab from that car?
CenCalBenz is offline  
post #26 of 36 (permalink) Old 06-08-2011, 07:34 PM Thread Starter
BenzWorld Member
 
Date registered: May 2011
Posts: 51
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
(Thread Starter)
I think i will just buy the whole modulator from here- https://mercedessource.com/node/7627

I was trying to figure out a way to retrofit this vcv onto the top of my injection pump and it doesnt look easy. I could fashion a plate that is secured by surrounding bolts which the vcv could mount to.
CenCalBenz is offline  
post #27 of 36 (permalink) Old 06-08-2011, 11:53 PM
BenzWorld Elite
 
Govert70227's Avatar
 
Date registered: Oct 2009
Vehicle: 2000 VW Golf Variant
Location: Leiden, Netherlands
Posts: 2,952
Mentioned: 0 Post(s)
Quoted: 4 Post(s)
Quote:
Originally Posted by CenCalBenz View Post
I could not find a vacuum modulator on the '84 turbo diesel that i was pulling the parts from. I couldnt get under the car and get a good look, so i wandered around looking for a car jack in one of the adjacent cars(its surprising how hard that was to find). I then got the car jacked up aways so i could get a quick look and there was nothing under there resembling the vacuum modulator that was in the picture that was posted.
The modulator for the 722.1 transmission is different from the later transmissions (722.3 and 722.4). They are not interchangeable. Your modulator was only fitted on 1980-1983 240D and 1980-1981 300D and on the gas models.
Govert70227 is offline  
post #28 of 36 (permalink) Old 06-09-2011, 11:29 AM Thread Starter
BenzWorld Member
 
Date registered: May 2011
Posts: 51
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
(Thread Starter)
Ah ok, well the real issue for me now is retrofitting this vcv onto the car. The throttle linkage does not have nearly as much travel as the vcv arm. Im thinking i can drill a new hole closer to the axis in the vcv arm and lengthen one of the levers on the throttle linkage. Hopefully that will increase the throttle linkage travel and decreases the travel needed on the vcv arm.

I hope that made sense.
CenCalBenz is offline  
post #29 of 36 (permalink) Old 06-09-2011, 07:06 PM Thread Starter
BenzWorld Member
 
Date registered: May 2011
Posts: 51
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
(Thread Starter)
I mocked up a mount for my vcv and it looks like it will work. With some minor tweeking the arm travel should be just right.
Attached Thumbnails
Click image for larger version

Name:	Pic0293.jpg
Views:	122
Size:	51.8 KB
ID:	380244   Click image for larger version

Name:	Pic0296.jpg
Views:	122
Size:	53.9 KB
ID:	380245  
CenCalBenz is offline  
post #30 of 36 (permalink) Old 06-29-2011, 09:28 PM Thread Starter
BenzWorld Member
 
Date registered: May 2011
Posts: 51
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
(Thread Starter)
I hooked up the vcv and drove My 76 300D around today!

It shifts through all th gears but tends to slip a little. I have yet to actually adjust the vacuum modulator and find the vacuum leak that prevents the car from shutting off.

I'm pretty happy with it. I heard a growling/grinding sound coming from the rear of the car. I'm didn't drive it more than a couple of miles but i never checked the rear end oil level. I just need to get a 27mm hex wrench??
CenCalBenz is offline  
Sponsored Links
Advertisement
 
Reply

  Mercedes-Benz Forum > General Mercedes-Benz Forums > Vintage Mercedes-Benz

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Mercedes-Benz Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











  • Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
     
    Thread Tools
    Show Printable Version Show Printable Version
    Email this Page Email this Page
    Display Modes
    Linear Mode Linear Mode



    Similar Threads
    Topic Author Forum Replies Last Post
    ML320 trans issues baisdelr W163 M-Class 12 01-28-2012 01:36 AM
    99 230K Odd Trans issues Kavkazia W202 C-Class 11 04-13-2010 03:14 PM
    TRans issues HELP! carybrief W126 S,SE,SEC,SEL,SD,SDL Class 3 05-05-2009 11:10 PM
    W126 TRANS ISSUES WARREN,C General Mercedes-Benz 2 03-10-2008 07:58 PM
    85 300d Trans Shifting Issues... .Help... tbic W123 E,CE,D,CD,TD,TE Class 6 10-02-2004 04:03 PM

    Posting Rules  
    You may post new threads
    You may 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 Off
    Trackbacks are On
    Pingbacks are On
    Refbacks are On

     

    Title goes here

    close
    video goes here
    description goes here. Read Full Story
    For the best viewing experience please update your browser to Google Chrome