What I have a time getting use to on these cars and the automatic tranny is the compression experience. For the last 17 years all the auto trans in wife's car's and our VW TDI's have no compression slowdown when letting off the throttle. My 240D just blows my mind every time I let off the go peddle, it's like stick shift gasser's only more then any of my Nissan trucks.

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'10 Chrysler T&C Stow-N-Go White. Grandpa's ride.

'13 Chrysler 200 Touring Candy Red. Grandma's ride.

Age and cunning will always over come youth and vigor.

Some diesels have 2 valves. Some have 1 valve. My 84 300SD has no valve.

My transmission has an interesting shifting characteristic. It usually likes to rev up before shifting. The transmission is not slipping. Before it shifts, the car starts to accelerate faster! The shifts are firmer when the transmission is cold, and smoothens out when hot. I could not claim ever claim that this transmission shifts "as smooth as butter."

However, in an advertisement for an 81 300D/SD/CD/TD, entitled "Mercedes-Benz unleashes two more high-performance Turbodiesels," they wrote: "Not even the Turbodiesel's transmission is the same. It is a compact four-speed hydraulic wizard of an automatic, a torque convertor device so quick that it can shift gears in 1/10th of a second, so smooth that many shifts are imperceptible."

As others have mentioned, a firm shift is better than a smooth shift. I also agree. But, there is nothing wrong with an imperceptible shift since that is what the car is designed for.

My '80 300TD just has one valve, and I also had to swap vacuum locations for tranny shifting issues. However, mine was just the opposite. It was shifting WAY too early, and flaring badly. I swapped the location of vac line to tranny, then played with the modulator valve on tranny. (passenger side on '80)
If it was running, it would be shifting fine...


Edit: Where are my pictures? I tried twice...

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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

It depends on the tranmsission, the 722.xxx have a vac modulator, the eariler ones on the diesels do not, they have an acelerator linkage operated lever instead.

If the tranny has a vac modulator, there will be a vac valve on the IP or on the valve cover, depending on model. Some also control the EGR, but that will only be on about 83 or later engines, earlier ones don't have an EGR.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Mercedesman, that sounds like an apt description of how the trans in my 82SD behaves. Starting with a trans that threatened to never upshift beyond 2nd ever again, I now have a trans that shifts pretty well, although I'm still tweaking. It does indeed exhibit the feeling of an increase of torque between 2-3 shifts, I think. Oh, darn

Pete,

I like to think that the additional accelaration right before the transmission shifts comes from the turbo kicking in.

The amount of airswitches on your engine, as far as I can tell, depends on the year it was produced, ie emission standards. And the model car. The 1983 240D has 2 airswitches. One for EGR the other for tranny downshift. My 1982 has 3. What each one is for, I have not figured out, because it runs fine. I know I have a EGR system so that is 1. but I have a bowden cable so the other ones are not for downshift.

This discussion has to be geared for either 240D with the 616 engine and the 722.1 tranny. Or the 300 turbo diesel with the 617 engine and the 722.2 tranny. Then we have the 300 nonturbo to discuss.

Dave

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1970 220D, owned 1980-1990
1980 240D, owned 1990-1992
1982 300TD, owned 1992-1993
1986 300SDL, owned 1993-2004
1999 E300, owned 1999-2003
1982 300TD, 213,880mi, owned since Nov 18, 1991- Aug 4, 2010 SOLD
1988 560SL, 100,000mi, owned since 1995
1965 Mustang Fastback Mileage Unknown(My sons)
1983 240D, 176,000mi (My daughers) owned since 2004
2007 Honda Accord EX-L I4 auto, the new daily driver
1985 300D 264,000mi Son's new daily driver.(sold)
2008 Hyundai Tiberon. Daughters new car

I am trying to install a '82 300CD engine into a '83 240D. It looks like I will try to use the 240D transmission first, as it has no obvious problems. I just don't understand the reasons for all the variations in terms of downshift.

The 240D has no obvious downshift control (vacuum line off one valvecover switch)? The 300CD has a cable. The valvecover of the 300CD engine has two vacuum switches, one triggering at idle, one triggering at full throttle. I won't be using EGR (I'll hook up some hoses, but I want to make sure it doesn't work), so possibly one of the two switches will connect to the 240D tranny for downshifting....

That's the only issue I haven't worked out in advance yet - the vacuum routing, including the fuel shutoff. Wish me luck, any suggestions are welcome.

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'83 240D with 617.952 and 2.88
'01 VW Beetle TDI
'05 Jeep Liberty CRD
'89 Toyota 4x4, needs 2L-T
'78 280Z with L28ET - 12.86@110
Oil Burner Kartel #35

http://i16.photobucket.com/albums/b1...oD/bioclip.jpg

Does anyoneone know where to get info on how the various models were plumbed in Europe? For any of us who have their EGR disconnected temporarily (for diagnostic purposes only, of course ), this would be a good setup to try. Shifting performance with the EGR was not the hot thing to work on at MB, I'm sure.

I haven't even been able to find anything on the US models so finding something for the Euro models may be even harder.

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DJ


84 300D Turbodiesel 190K with 4 speed manual sold in 03/2012

do you mean vacuum diagrams ?

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Audi TT

yes, I meant vacuum diagrams. I have them in my FSM for the 617, and they changed them a lot. But I'm surmising they didn't have so many variations in Europe.