First, Second & Third, No 3-4 Shift

1. Control valve assembly and spacer plate.
a. 3-4 shift valve or 3-4 throttle valve stuck.
b. Plugged spacer plate orifice.
2. Center support.
a. Plugged or undrilled oil passages.
b. Loose or missing center support attaching bolts.
c. Cracked or damaged fourth clutch piston.
d. Damaged, missing or improperly assembled fourth clutch piston seals.
e. Improper plate usage.
f. Burned fourth clutch plates.
g. Binding overrun clutch plates.
3. Case porosity.
4. Orifice cup plug missing in 3-4 accumulator passage in case.
5. Leakage between accumulator piston and pin.
6. 3-4 accumulator bore damaged.