85 3000D Trans modulator/vacuum issues
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From: Hazel Green, AL
1985 300D, 1992 300D, 1982 300SD
85 3000D Trans modulator/vacuum issues
I am new to this forum (today). So far unsucessful in my search for documentation on how to trouble-shoot and set modulator valve and vacuum supply to it. Haynes, Chilton, CD sets are of no use. Does anyone know where the answers are?
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Joined: Sep 2009
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From: So CA
1984 300D,82 Volvo Diesel
I would read this first
http://www.continentalimports.com/ser_ic20242.html
See if you can find info here
Repair Links
http://www.peachparts.com/shopforum/forumdisplay.php?f=82
http://www.peachparts.com/Wikka/DoItYourSelf
http://www.continentalimports.com/ser_ic20242.html
See if you can find info here
Repair Links
http://www.peachparts.com/shopforum/forumdisplay.php?f=82
http://www.peachparts.com/Wikka/DoItYourSelf
Last edited by 300Dman; Dec 25, 2009 at 07:31 PM.
Thread Starter
Newbie
Joined: Dec 2009
Posts: 7
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From: Hazel Green, AL
1985 300D, 1992 300D, 1982 300SD
300D Trans modulator/vacuum issues
300Dman...Appreciate the response. I am guilty of one of the ingenious repairs noted in the link you provided. It also mentions to set trans pressure using the modulator valve according to a data manual. Are you or anyone else aware of this data manual and where it can be aquired. I have 4 of these old MB diesels and have various trans issues. I am sure the settings vary with year/model. I am ordering a Mityvac kit to help troubleshoot the vacuum supply.
Any other guidance or suggestions on this subject will be most appreciated.
Any other guidance or suggestions on this subject will be most appreciated.
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Joined: Sep 2009
Posts: 48
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From: So CA
1984 300D,82 Volvo Diesel
If you do not already know where to find it I would go to the Diesel Giant Web Site and he has a pictorial on locating where the Model Number of your transmission is.
There is a comapny ATSG that sells a very spartan Transmission rebuilding Manual that has some trouble shooting stuff and also some setup info.
You can get the origional Manual on eBay for a total cost of around $27 or there is an eBay seller who apprently runs of copies of the same manual for around $16.
However, I would do a close read of the the repair links on this. You need to adjust the Vacuum Valve on the top rear of the Fuel Injection Pump. On mine there is something called the Bodwen Cable the adjust when the shifts happen and the Kick Down.
There is the Modulator adjustment itself that if you read the repair links most adjust by trial and error.
And, the 85 has some other type of Valve in the Vacuum System. I did not pay attention as I do not have an 85.
The main problem is that as the article said if you are adjusting a worn Transmission you might make it better but it will not be perfect as re-adjustment does not fix wear.
There is also a company Superior Shift Kits that makes some spring mod kits that are helpful but I would not mess with them until you have tried adjustments.
Unfortunately while the Mercedes CD Service Manual set ($27) is a wealth of knowlege on most everthing else on the car they do not suppply that info on the Transmission.
There is a comapny ATSG that sells a very spartan Transmission rebuilding Manual that has some trouble shooting stuff and also some setup info.
You can get the origional Manual on eBay for a total cost of around $27 or there is an eBay seller who apprently runs of copies of the same manual for around $16.
However, I would do a close read of the the repair links on this. You need to adjust the Vacuum Valve on the top rear of the Fuel Injection Pump. On mine there is something called the Bodwen Cable the adjust when the shifts happen and the Kick Down.
There is the Modulator adjustment itself that if you read the repair links most adjust by trial and error.
And, the 85 has some other type of Valve in the Vacuum System. I did not pay attention as I do not have an 85.
The main problem is that as the article said if you are adjusting a worn Transmission you might make it better but it will not be perfect as re-adjustment does not fix wear.
There is also a company Superior Shift Kits that makes some spring mod kits that are helpful but I would not mess with them until you have tried adjustments.
Unfortunately while the Mercedes CD Service Manual set ($27) is a wealth of knowlege on most everthing else on the car they do not suppply that info on the Transmission.
Thread Starter
Newbie
Joined: Dec 2009
Posts: 7
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From: Hazel Green, AL
1985 300D, 1992 300D, 1982 300SD
300D trans modulator/vacuum issues
Thanks again 300Dman for your response. This is a real learning experience for me. The information I have collected in the last few days is very enlightening and appreciated. Once a few items are delivered I'll get to work. I'll let you know how things work out.
