Maybe I misses a thread in my search, but I can not find this info. I have a new modulator ready to install. Old one id out, car in stands. This is a newer black style modulator.

The new one has a "key" that goes in first, followed by the cap. The key is the interface to the cap that turns. What I am wondering is what position the key should ideally be in before I pop the cap on? Since the cap will stop at the vacuum port I am limited in how it can be turned.

Concern is that the valve is setup as a screw type closure. What I mean is that there is a huge variable in adjustment as the center screws in or out to change a gap. Or if its a ball type, then it really does not matter as much as each revolution opens/closes it again.

__________________
1991 560 SEL / 185k miles
1992 750il / 17k miles - project car

Well I figured its screw type. So I will install with it near one end of the adjustment (softer). Drive, adjust, drive then cap it.

__________________
1991 560 SEL / 185k miles
1992 750il / 17k miles - project car

Got it pretty well for now. I counted 22 full turns from soft to harsh going clockwise. So I backed down to 17 turns from harsh. (With full harsh one will also notice that the plunger will not press in). This gave me 5 full turns from soft. Was still a bit harsh, so I turned soft one more. Shift feel more like shifts now instead of some guy with a hammer inside the trans.

When I put the cap on I found it was basically keyed and will not complete a full turn. So I had to turn the key a half turn to harsh, so when I put the cap on I could turn it back to where it was but then allow me to slowly adjust to firmer ****s using the knob.

Note: lube the knob at the base as it rides on a rubber o-ring. I did not so turning it by hand makes it rather difficult. Once the knob is on I am not sure if it can be removed. Seems not. So since it can not make full turns. I suggest you do as above and do NOT install the cap until the very end. In fact, if I replace this modulator again I may not install the cap at all. I dont think the cap it needed to seal the modulator. At least I hope not. That way one could make much more sweeping adjustments.

__________________
1991 560 SEL / 185k miles
1992 750il / 17k miles - project car

Did the shift quality change on WOT or just half throttle etc?

I adjusted my modulator too however it did not allow me to do full turns. Rather the hole "tuning" range was about 3/4 of a turn.
It did however make shifts considerably softer in the lower revrange, however I am pretty sure on WOT there is not difference

__________________
Smoke Silver 1994 E220 Coupe Automatic
0 kilometers 6 September 1994
100,635 kilometers - 6 September 2010

I have not tried WOT yet. But at WOT vacuum is greatly lessened therefore harsh shifts would make sense.

__________________
1991 560 SEL / 185k miles
1992 750il / 17k miles - project car

I think in theory at WOT there should be no vacuum unless there are serious restrictions somewhere

__________________
Smoke Silver 1994 E220 Coupe Automatic
0 kilometers 6 September 1994
100,635 kilometers - 6 September 2010

Is a One Time Only use...Put it on and that's it...Take Off and it's destroyed.
(It does allow a Miniscule adjustment once capped,less than 170 degrees)

Someone pointed this out in another post this weekend.

We suppose,you're supposed to make ALL the correct adjustments with the
little Metal "T" handle [Using Pressure Gauges,so you get it absolutely correct]
then apply the "CAP".

Yet another way Mercedes FORCES you to buy new parts.

__________________
'84 300SD sold
124.128

Well the shifts are still MUCH better. The cap does not seal it further. Thoughts were that the "T" part, where it enter, may be a vacuum leak source however odd that may be. Thus the reason behind the -ring and cap design that "seals" the "T". But after putting the T on, no change. So there was no leak with it off.

Thus removing the cap and keeping the "T" in a safe place would be a way to make many adjustments.

In my case I think I have an intake leak. So when I replace all those gaskets and such I may find myself needing to make adjustments again.

__________________
1991 560 SEL / 185k miles
1992 750il / 17k miles - project car