diesel trans question

Hi,
I have a 1983 300D with the 4sp auto. I replaced the vac. valves on the valve cover, as they were worn through. It shifted fine before the replacement, but
after that, I have a very hard 1-2 shift, slower 2-3 then a very long 3-4 shift. With each longer shift, there is no flare of the rpm, etc., but it takes a while in between gears, which bothers me, and Id prefer for the shift to be harder, so that parts arent wearing as fast. I assume Id need to adjust the bowden cable and perhaps the vacuum modulator, but any advice on which to do and in what direction?
Thanks,
JMH
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The transmission's shift firmness is controlled by the vacuum valve on the aft end of the injection pump. The greater the vacuum the softer the shift. At light throttle the vacuum valve supplies most vacuum to the transmission's vacuum modulator and at wide open throttle no vacuum is supplied to the modulator.
I suspect insufficient vacuum is your car's problem; check the vacuum connections at the valve cover etc..
I advise you to restore its prior performance BEFORE doing anything to the vacuum modulator so there's a base line for the modulator's adjustment, if any is then needed.
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Thanks for the info. Vacuum is strong throughout the system, it is not a leak. It has something to do with the adding or venting of vacuum which was changed when I replaced the 'piggyback valves' on top of the valve cover. the old ones were almost completely worn down, and replacement of them now will change the depth, etc that they get pushed in, and thus the operation of those valves. That is what has caused the change, but I dont want to go adjusting stuff before being sure what to adjust. Thanks, JMH
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