Trans. Slips In All Selector Positions

1. Check modulating pressure, adjust if possible. If not adjustable, check modulating pressure control guide for ease of operation.
2. Check vacuum line from intake pipe to vacuum control unit for any restrictions. On models with diesel engines, check vacuum control valve.
3. Check hydraulic pressure as follows:
a. Loosen oil cooler line on transmission oil cooler, start engine and check for hydraulic oil.
b. Disassemble shift valve housing, clean and ensure working pressure control valve is operational. Replace shift valve housing if necessary.
c. Remove and check primary pump, replace if necessary.
d. Switch on control valve and check for ease of operation.
4. If working pressure is satisfactory, but there is still no engagement, check one-way clutch and wheel assembly.