Originally Posted by
MR TRIKE
My Company, The Trike Shop, built the Runabouts and RoadHawks. All automatics where from 1968-1974 Type 3 Fastbacks or Squarebacks. The shifting is regulated by vacuum which is pulled off the Intake Manifold to the Modulator Valve located at the rear of the trany. You can adjust the shifting pattern sometimes by removing the vacuum hose from the Modulator Valve and using a 1/8 inch screw driver turn the screw out several turns to get it to shift out of 2nd gear sooner. General Rule is turn screw IN to stay IN gear longer and Turn OUT to shift sooner. Always count the turns so you go back to where you where if needed. If, when you take vacuum line of modulator, there is transmission fluid in line, then the diaphragm is leaking and is Bad and needs to be replaced. It is also possible that the internal seals inside trany are losing fluid pressure and causing the shifting problem. Rebuilding the trany is needed at that time. Start with the easy way first. KEEP-ON-TRIKEN Dick