Useless black box - vacuum? 1984SD

[DieselDaze]

I have disconnected and bypassed the black box vacuum 'flap valves' and all EGR tubes, and plugged up any open hoses. Car shifts fine.
Will this elimination of the 'flap valves (black box) leave TOO MUCH vacuum, unreleaved by these valves, and will this harm the transmission?
1984 300SD

[pawoSD]

I'm actually going to do this myself soon...I don't believe there's any issue of too much vacuum....I've never heard of one anyways.

[BenQ]

There will be no problems disconnecting the egr and "black box". Really if you just plug the vac. line to the egr control (black box) you will disable the egr, You don't need to take any parts off the car or plug the egr tube. Just taking the vac. from it wil have the same effect. Keep in ming though that 1984 diesels are not emissions regulated by the gov. you will be disabling an antipolution device. Of course if the valve in the control are leaking badly the egr isn't working anyway.
Myself...I fixed mine to work properly.
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83 300sd
3 Fords

[Cateaux]

Originally Posted by DieselDaze

Will this elimination of the 'flap valves (black box) leave TOO MUCH vacuum, unreleaved by these valves, and will this harm the transmission? 1984 300SD

On mine I ended up with really soft 2-3 and 3-4 shifts after plugging the 2/3 valves. This is because the modulator and vacuum control valves were adjusted to compensate for the vacuum leak. With these adjusted properly and all vacuum leaks plugged, the transmission now shifts fine.