TH400, Vaccum module. (Righty tighty,left loosey) Now am i current on this, but turning the inside bolt of the module, to the left loosening the spring, makes shifts faster and on less rpm, and to the right is slower shifts at higher rpm shifts ?? At slow area's i'm at high rpm an no shift change, so i'm guessing 2 to 3 turns to the left should do it ... or is it the other way around ?
You have a replacement vacuum modulator? Turning that screw clockwise will make your shifts harder & at higher rpm. It takes quite a few turns to make a significant change, and some driving to test out the the results under varied conditions. I'd keep a record of how much the screw has been changed, so as not to loose my place over all this. Bruce Roe
Ok got up first thing this morning, before work. Counter clock direction 3.5 turns, to the module, and now, i think it's worst !! Drove it to work to see how it is and gonna go out at lunch time, and re-adjust it clock wise
Be careful, you can abuse that adjustment to the modulator. It is possible to lower line pressure to the point where clutches can slip.
is it me or what, just adjusted module again, was tottally loose, but now after tightening and car is stumbleing hard at take off, idleing good, but slam the gas and straight drop. (like it's sucking air in). Guess i'm go back under her !!
"Lowering the line pressure", what do you mean ? loosening it up to much, where there's a slight pause in gear changes ?
Line pressure affects shift firmness. If you turn the modulator screw out too much, you can lower the line pressure to the point where clutches slip, and that will wear the transmission. Adjust the screw so that at minimum throttle, it shifts 1-2 at 9-12 MPH, and 2-3 at about 20-25 MPH. Then leave it alone.
