Excessive Shock or Flares On 3-4 Upshift Or 4-3 Downshift

Excessive shock or flares on 3-4 upshift or 4-3 downshift

Diagnostic Procedure:

1. A/T clutch pressure control solenoid valve B defective

2. A/T clutch pressure control solenoid valve C defective

3. Foreign material in separator plate orifice

4. 3rd accumulator defective

5. 4th accumulator defective

6. 3rd clutch defective

7. 4th clutch defective

Also check for:

- Check for a stored DTC, and check for loose connectors.
- Inspect A/T clutch pressure control solenoid valves B and C filter/gasket and the O-rings for wear and damage, and inspect the solenoid valves for seizure.
- Check for a clogged orifice in the separator plate. If the orifice is clogged, remove it and clean the separator plate orifice.
- Check the 3rd and the 4th clutch pressures.
- Inspect the clutch piston, the clutch piston check valve, and the O-rings. Check the spring retainer and the retainer seal (for 3rd clutch only) for wear, damage, and peeling. Inspect the clearance between the clutch end-plate and the top disc. If the clearance is out of tolerance, inspect the clutch discs and the plates for wear and damage. If the discs are worn or damaged, replace them as a set. Inspect the clutch wave-plate height. If the height is out of tolerance, replace the wave-plate. If the discs and the plates are OK, adjust the clearance with the clutch end-plate.
- Inspect the 3rd clutch feed pipe. If the 3rd clutch feed pipe is scored, replace it and the O-ring under the feed pipe guide.
- Replace the secondary shaft if the bushing for the 3rd clutch feed pipe is loose or damaged.
- Check the 3rd accumulator piston, the O-ring and the springs in the regulator valve body for wear and damage.
- Check the 4th accumulator piston, the O-ring, and the springs in the servo valve body for wear and damage.