It sounds like you are lucky...you have too much vacuum.
This means your plastic valves and plumbing are ok...if anything they would be reducing the vacuum. If you are not making 0 hg vacuum at full throttle, it sounds like your regulator valve that you adjusted is bad, or you have the wrong orifice. The valve will only work if it has the proper restriction to work with. You can look at the regulator valve as an 'adjustible orifice'

It's like a resistive divider in an electronic circuit.

Vacuum= voltage
orifice size=resistance

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D

The pressure considered proper at the trans was changed on some of our cars by tech bulletins put out since the manuals were printed.... check at alldata.com for your particular car.. it shows titles of the tech bulletins...

Any way to "properly" choose the correct orifice? I did not see a methods in the sometimes cryptic FSM, and has planned to experiment a bit.

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One more Radar Lover gone...
1982 VW Caddy diesel 406K 1.9L AAZ
1994 E320 195K

Hello everyone and thanks again After I adjusted the two settings on the regulation valve:

I now have the 15hg at no throttle and 0hg at full throttle.


I went to the site:

You have to pay to get that pressure information right? I could not find it on that site. Another question also is, are you referring to the vacuum measurements I mentioned above or are you referring to the pressure on the modulator valve? Does anyone have a 1983 300d and has the information from that site?

Thanks again,
Adiel

I don't know why you could not get to that site...here is a google search for it..

http://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=alldata

The titles of the tech bulletins are free.... you read them.... if you find something you need to check out you may can ask a local dealer... or find someone who has an Alldata subscription ... about 25 for first car... 15 for second, etc....

I can't memorize all the particulars on the stuff I run across.... way too old for that.. I just saw something which caught my eye regarding the vacuum and the trans which had been changed from what they wanted it to be when they released it from the factory... may not apply to your car.... just posted it as a heads up for anyone reading this thread...

Ok, I went to alldata and found the following relevant articles on the 1983 M-B 300D Turbo Diesel:

27_090 FEB 93 A/T - Vacuum Modulator Adjustment
ATRATB028 OCT 90 A/T - Engine Vacuum Testing
27_006 JUL 83 A/T - Vacuum Control Valve Updated

I was about to pay for the site to access the articles for $24.95 but then I realized it is only for one year's access! I would have imagined if they are charging you $24.95 for one vehicle that it would be for the LIFETIME of that vehicle! In any case, I decided not to sign up to that site but, if anyone here has those three articles from ALLDATA, can you please send them to me or post them here.

Thanks everyone,

Adiel

I don't imagine there releaseing TSB's and such very often for a twenty year old car. One year subscription is probibly plenty to copy the information you need.

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One more Radar Lover gone...
1982 VW Caddy diesel 406K 1.9L AAZ
1994 E320 195K

Hey, that price is cheap compared to the official Mercedes-Benz site StarTekInfo. Their price is $18 for 24 hours, $95 for 7 days, $275 for 31 days, or $2950 for a year. Yes, that's in American Dollars.

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Rick Miley
2014 Tesla Model S
2018 Tesla Model 3
2017 Nissan LEAF
Former MB: 99 E300, 86 190E 2.3, 87 300E, 80 240D, 82 204D Euro
Chain Elongation References

The following describes my journey and the data I've collected since trying to solve my "flaring" problem between 2-3. Much of it is the same for tranmission adjustment.

The most comprehensive discussion on this is from Steve Brotherton (some kind of tech) who seems to know these trannys inside and out. Perhaps as much as 6 factors need to be in balance for the trannys to shift properly. I have made great improvement even though its not perfect yet. My final adjustment is where I simply ran the car without vacuum to the tranny. Hard shifts but no flaring.

Regardless of your particular issue, you'll find this printout invaluable.

His information (5 page printout) is available at:

www.continentalimports.com

click on "articles" and then "mercedes-benz transmissions".

He has pics and the whole shootin' match.

Don

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DAILY DRIVERS:
'84 300DT 298k (Aubrey's)
'99.5 Jetta TDI IV 251k (Julie's)
'97 Jetta TDI 127k (Amber's)
'97 Jetta TDI 186k (Matt's)
'96 Passat TDI 237k (Don's
'84 300D 211k Mint (Arne- Undergoing Greasecar Conversion)

SOLD:
'82 240D 229k (Matt's - Converted-300DT w/ 4 speed

People need to realize that the internet is not free. Sure there is plenty of information out there that is (like this site) but specialized sites have spent a lot of time and money in development and have ongoing expenses to keep the site running. If you find the info you need for a reasonable price then BUY it. Don't ask someone else who did buy it to give you a copy.
Sorry to rant but I make much of my money by selling information online and hear from time to time how I should not charge for it but should provide it for free as a "service to the industry". Same reasoning does not fly when I go grocery shopping or fill my car with fuel.

This is an excellent point. For example, if your motor is not makeing the power it should, even if your vacuum and trans are absolutly perfect, you'll have your foot further in it and therefore it will shift harder than it's "suposed" to. The inverse is true, and I don't think the people trying to increase power think of this, but if you have a motor makeing much more power than stock, and you only have to be on the throttle half as much as you normaly would for a given acceleration, the trans will shift softer, and quite possibly slip under the greater power. Theoretical, but I think the logic is sound.

I too still have a 3-4 slip at light throttle I'm still playing with. I need less overall vacuum at light throttle positions, have about 13 inches now at idle, about 10 when it still slips 3-4. I'll figure it out eventually. Or put in a stick..

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One more Radar Lover gone...
1982 VW Caddy diesel 406K 1.9L AAZ
1994 E320 195K

Simply changing the trans fluid and filter will not dissolve the varnish built up in those tiny holes and sealing balls in them.... which control the hydraulic fluid going to the hydraulic actuating parts of the automatic clutches......so if the flow is restricted then the action is like ' slipping ' a manual clutch... which , if left very long, wears out the friction material on the clutches....
If you look up TRANS-x and look at the posts you might want to give that a try... after you replace the stuff mentioned in the above posts.... cheap and does not keep you from going to the next step if it does not work... but give it a couple of hundred miles ... and be sure to read the can and make sure you know the total fluid capacity of your transmission.... you may need two cans like I did in my 81 wagon trans....You can syphon out the amount you need to remove so you can put the Trans-x in ...

Hello leathermang, before I did the a.t. fluid/filter change, I had poured half a quart of TransX ATF which did not help. I believe you are referring to another product from TransX and not the ATF.

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Sorry, did not know they made plain atf....
I am referring to their product which is listed as " tuneup and leak seal"....

Thanks leathermang, wolf_walker, diesel don and dsmess for your help.

I have another good update:

After I did the test where I disconnected the vacuum line to the modulator valve and saw that the shifts where good, I re-connected the vacuum line back up to the modulator valve and I had tighten the modulator valve (clockwise). The car went back to slipping again so tighteting the modulator valve did not help. At this point the problem defenetly seem to be in the vacuum that was going to the modulator valve. Remember the Brake Booster Vacuum Line that I had bought? I went ahead and took out the old one that was in really bad shape, put in the new Brake Booster Vacuum Line that I bought, made sure the vacuum line was still connected to the modulator valve and guess what? NO SLIPPING!!! So it looks like a big part of the problem was in the old VALVE on the Brake Booster Vacuum Line! Then I noticed it was shifting a bit early from 3-4 so I went ahead and adjusted the Bowden Cable, shifting also improved. Now my question is since I had originally tighten the modulator valve (Thinking that that was the problem), should I go ahead and loosen the modulator valve? (counter-clockwise) Another question when going in the expressway at 70mph, I notice the RPMS are higher now than before (like around 4000) is this normal? The engine almost sounds like it should shift into one more gear....

Thanks Everyone,
Adiel

ps: leathermang, I will try the TransX "tuneup and leak seal" in the near future.

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