Hello everyone, After the last ride without any problems, I parked my 67 GS. Started today and I can't get into gear, oil level is good, shift linkage works..!? Could it be Modulator? How can I test this? Thanks for your help. Emanuel
Unlikely it is the modulator. A bad modulator can make the transmission slip, or not shift out of 1st gear. If you remove the modulator, you can test it to see if it holds vacuum. Also point the vacuum connection down. If any ATF comes out, replace it. Complete sudden loss of Drive is unusual. If the fluid level is normal, and the linkage is working, you'll need to check transmission oil pressure with the right high pressure gauge.
And just to add to this, as Larry mentioned, fluid level has to be ruled out. I know when my car sits over winter, it leaks trans fluid like a sieve. The tranny needs a complete going through no doubt, but every year I add like a gallon of trans fluid. It doesn't leak at all during summer and when I drive it fairly frequently. But I know that on my first start up, it won't even go into drive it is so low. I know sooner or later it'll need a rebuild, but it still snaps the shifts and chirps every year when I add the fluid.
Thanks for your comments. Checked the oil level and the vacuum modulator again today. There is enough oil in it and no leaks in the vacuum line. What surprises me is that the car can move in any position except parking?! Maybe something loose inside that won't engage the gears? I first have to drag the car to my workshop and lift it so I can work better. That we'll take a while.
Refer to "LOW LINE PRESSURE" 1. Pressure regulator or boost valve stuck. 2. Wrong boost valve and sleeve. 3. Excessive pump gear clearance. 4. Pump body wear in gear pocket. 5. Excessive wear on pump cover (Stator). 6. Porosity in pump body or cover. 7. Pump to case gasket mis-positioned. 1. Piston seal damage on Forward, Direct, or Intermediate clutches. 1. Oil sealing ring damage or mis-assembly. 2. Sealing ring groove damage or wear. 1. Pistons or seals damaged. 2. Servo cover or gasket damaged. 1. Damaged or porosity in valve body area. 2. Intermediate clutch cup plug missing or 1. Blocked or restricted filter. 2. Damaged or missing "O" ring seal on pipe. 3. Intake pipe damaged or cracked. 4. Damaged intake pipe case bore. 1. Linkage not properly adjusted. 2. Manual valve loose from rooster cone pin. 3. Rooster cone nut loose on manual shaft. 1. Stator roller clutch damaged (Vehicle moves, but is very sluggish). 2. Turbine hub splines stripped or broken. 3. Turbine or pump vanes damaged. 4. Mis-stabbed (Damaged hub and gear 1. Internal splines stripped or damaged. 2. Differential damaged or axle broken. (Does speedo work in forward gear?
Ok, what's trying to say. I can move the car back and forth without resistance in levels 1,2, & D, no movement possible except in the park position. It doesn't matter whether the engine is running or not.
Addition: It was the oil filter that fell off that caused the shifting problems. New filter installed and refilled with oil. Everything is working fine again.
