VCV, SwitchOver Valve, K1, K2...i got a multi-problems transmission
 

o.k. if you are ready for this, here we go:

My car is a wonderful Mercedes1983 240D automatic Gold/Palomino Leather(132k). i'm very proud of it. It is pretty straigh...and strong.
AT first, my car experienced high rpm shifting from 2-3 and 3-4.

I went to my mechanics and he returned me my car with a slipping shifting (at full throttle) from 2-3 and 3-4 with almost no horse power and it shifted too soon 2-3 and 3-4.

I went to a second mechanic then he changed a broken switchover Valve, changed the transmission oil and filter and went to a road test. Same thing. He was not able to adjust the transmission modulator.

i bought a Mytivac, park the car on the street in full sun(It's still cold here in Montreal) and did the pressure test and here are the numbers:
(this is the vacuum diagram: http://home.comcast.net/~phantoms/va..._240d_auto.jpg )
1-Vacuum from the pump: 25``
2-Vacuum before the green Surge damper: 17.5``
3-Vacuum after the green Surge damper: 17``
4-Vacuum at the exit of the vacuum control valve (at idle): 0
yes... 0

Now my question is: do i take the vacuum correctly?
if i well understand, there is a line(with the green Surge damper) bringing vacuum at the top of the vacuum control switch then going out by the side of the valve(near the adjustment bolt) going to the switchover valve then to the transmission. I did plug the mityvac near the adjustment bolt. Am i right?
So can i fix the valve??? If i try to adjust it (with the bolt) what are the effect i mean if i turn clockwise?
On the other hand, should i change it?

After that, i disconnect the vacuum line going down to the modulator, and went to a road test to see what change it makes.. Nothing change.
The problem is that the less vacuum (or zero in my case) to the modulator on the transmission, the harder the shifts would be, and I should have no slipping.
So there is another problem here. TheDon toll me about the K2 to fix my 3-4 slipping problem, what about the K1 for the 2-3 problem?

Thanks again...
KarL

Your link doesn't work. Have you tried pulling vacuum on the trans modulator directly? If it doesn't hold vac then you need a new one.

i did, sorry, my mechanic did it and said that it was holding pressure with no leak...
Is there an another way for the modulator to be broken ??
but i got no vacuum going out the vacuum control valve(in the ip) so how can adjust it to let the vacuum go through ?

There is some good info here about adjusting it and checking to see if it is working properly. Try searching for something like "adjusting the vacuum control valve" and see what comes up. I checking mine awhile back so I know the info is here.

I read almost everything about it but nothing clearly talk about cleaning or adjusting the VCV when nothing is going through...

Here's what I did with mine:

I took mine off the car, and opened the front "plate".
Under that plate, you can see a coil spring that presses up against a plunger that deals with the vacuum line on top.
I cranked up the tension with a pair of plyers with one hand, and tightened the nut with a wrench with the other hand.
That really cut down the range of vacuum from (I'm guessing) around 0 - 5.
It shifted harsh, clunked into first, the whole bit.

I then loosened up the nut again, and the spring wound out a little. That opened up the range of vacuum, and the eliminated clunking downshift.

So, what does this mean to you? Probably nothing. You might need to get a new one. You can get one for approx. $50 every now and then on Ebay.

I would still take it off the car and see if I couldn't fix any obvious problems with it, though.

you know what, i'm going to try it...i got nothing to lose....i run my car without what it is suppose to do anyway, so in the worst case scenario, i buy a new one...

One option you might have is to get the part used from a junker in your area. I also think it would beat dating the majority of mechanics in your area as well.:D

If your trans did not slip at full throttle before you took it to the first mechanic and now it does, he probably adjusted the trans modulator counterclockwise. That needs to be put back to the correct pressure. Disconnect the vacuum line to it and turn it clockwise until you have an adequately firm shift at full throttle like you did before. Otherwise you will be putting another transmission in the car prematurely down the line.

One note for leaking trans modulator:

The rubber cap at the end is under $5 and may be the problem.
Whole modulator is $50 and is not always needed.

FYI

I went for an another road test after i discovered than i unplugged the wrong line going to the transmission and it's not slipping anymore...
From there the problem wasn't the transmission or the k 1 or 2...i decided to clean the VCV, lubed it and reinstalled it....didn't works...:confused:
I removed it again, reopened it and saw than the spring wasn't in place, fixed it, reinstalled the VCV...plugged the vacuum gauge, try ajusted the VCV on one side, on the other side and...Drummroll...nothing...F"*$*"!"?*!*$*CK
So i decided to recheck all vacuum line...:mad:
then i checked the line to the transmission oups, i got something here...nothing from the VCV but here yes a very beautiful 17" so i decided to played with the throttle and the arrow on the gauge moved down!!!
After this little moment of happiness(actually, i danced in the middle of the street) i played with the bolt on the VCV and i been able to set the pressure just a little bit under 15"(read that somewhere) putted full throttle and i obtained a reasonnable 8". i went to a road test, everything plugged of course and it wasn't bad at all, a little rought but its not slipping any more... From there i parked the car on the sideway, went under couples of time and now everything is just fine, not perfect but i'm so proud of what i did...i'll finish it tomorrow...but i cannot take all the credit so thank you guys for helping me
KarL