Adjusting IP linkages and Vac curves.

NEW Modulator (on trans) :

12hg at idle, dissapears at WOT.

Key is two positions from the 12:00 position turned CW. (see table below)

Shift
1-2: almost never happens (starts in 1st gear only when I start in L)
2-3: almost too harsh, sometimes takes longer than is neccessary (happens at 30kmh regardless)
3-4: VERY harsh, occurs at 40kmh regardless of any throttle or vaccum input.

At higher RPM's such as the 0-60 test, shifts into third then into fourth almost simultainiously.

as I adjust the modulator CW, no change.
as I adjust the modulator CCW, clunky downshifts no change in upshift pattern.

Control rod:
When set at no slack at initial throttle take up (I assume to be when free travel rod slack is taken up.) no automatic downshifts (not using switch)
as I shorten rod, shifts spread out more, but I loose automatic downshifts.


Any input appreciated,

thanks,

Ryan

__________________
RIP: 80 300SD
RIP: 79 450SEL
2002 E430 4matic (212,000km)
2002 ML500 'sport'

____________________________
FACEBOOK: PANZER450

Keeping it at the top...

__________________
RIP: 80 300SD
RIP: 79 450SEL
2002 E430 4matic (212,000km)
2002 ML500 'sport'

____________________________
FACEBOOK: PANZER450

Panzer -

First: Does the new modulator hold vacuum?

Second: You need to measure the modulator pressure through the test port to accurately set it. Theres no good way to ballpark it I have found. I am looking at doing this myself and almost have a set up.

Third: You may have other small leaks in your vacuum system that cause the vacuum to not rise and fall at the proper rates. For example my brake booster leaked yet my vacuum radings were fine.

Good luck,
dd

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-------------------------------
'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car

could you take a pic of your modulator? I was looking on my fresh rebuilt trans and did not find the green thing on the drivers side. there is a red thing on the passengers side that a vac line attaches to.

__________________
-Trevor

OBK #12
1980 300SD 333,XXX miles - Totaled
1986 Mazda RX-7 212,XXX miles - impounded and auctioned off
2005 Jeep Liberty CRD Limited 33,000- SEGR, Provent, Fumoto

Modulator will be GREEN 1981 and newer.

Here's what I've been doing to get this set up.

The vaccum pump functions perfectly, and the modulator and the VCV both hold vaccum very well.

I have an electric vaccum pump (when adjusting) attatched to the main branch coming from the vacuum pump, so I don't have to have the engine running al the time, it gives the same vac levels as the mechanical pump. I use it to set my idle vac pressure.

What I am confused about is where to set the modulator itself. I know how, but I just don't know if the key is 180 degrees of adjustment or is it infinite. (like a tap), because as some of you know, when you buy a new modulator it doesn't come assembled, you have to put the key in after you install the unit into the transmission. So I never really had, and still don't have a starting point, other than someone casually mentioning in posts that you should have ~15hg at idle, and 0 at WOT.

explain "test port" please...

__________________
RIP: 80 300SD
RIP: 79 450SEL
2002 E430 4matic (212,000km)
2002 ML500 'sport'

____________________________
FACEBOOK: PANZER450

here : trans modulator setting 81 300D


Hydraulic pressure. Adjustment by turning the T of the modulator.
This is basic adjustment, fine adjustment is done with vac (on the IP).

Tom

Oh! I see

Ok, so what kind of hydraulic pressures am I trying to achieve?

and is there an absolute zero point on the modulator? can I turn it too far in either direction?

__________________
RIP: 80 300SD
RIP: 79 450SEL
2002 E430 4matic (212,000km)
2002 ML500 'sport'

____________________________
FACEBOOK: PANZER450

Well whaddya know, I checked me NEW modulator and it was indeed leaking pretty bad.

I guess that goes to show and it also seperates the real mechanics who check these things, from the ones that just assume.....

added some lube to the o-ring and it holds vac now and shifts great!

just got to soften the shifts a little..

__________________
RIP: 80 300SD
RIP: 79 450SEL
2002 E430 4matic (212,000km)
2002 ML500 'sport'

____________________________
FACEBOOK: PANZER450

What is your tranny #?
Is it listed in the linked thread?
Do you see the port (must be near the modulator, 12 mm? hex-head)?
Unscrew and compare the threat with the banjo at the ALDA.
Connect a gauge to the port, disconnect the vac line to the modulator, start engine, in P at idle you have to read the pressure out of the list. Pressure is changed by turning the modulator T.
Be careful it is hydraulic pressure (tranny oil).
When this work is finished (do not forget to replug the vac line to the modulator) all other adjustments are made with vac-value towards the modulator by adjusting the valve on the IP.

Tom