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Home >> Buick >> 2011 >> Lucerne CX >> Repair and Diagnosis >> Transmission >> Automatic Trans >> Automatic Transmission - 4T65-E - Diagnostic Information And Procedures >> Diagnostic Information and Procedures >> Harsh or Soft 3-4/4-3 Shift Feel

Harsh or Soft 3-4/4-3 Shift Feel

Harsh or Soft 3-4/4-3 Shift Feel

Checks Cause
DEFINITION: One of the two following conditions occurs during a third to fourth gear steady throttle upshift, or a fourth to third gear coast, or a light to moderate throttle detent downshift:
  • Harsh shift feel - an unacceptable quick gear change occurs.
  • Soft shift feel - an unacceptable long gear change occurs.
Automatic Transmission Fluid Level, soft shift only Low fluid level
Transmission Main Line Pressure Low or high transmission main line pressure
Oil Filter Assembly, soft shift only
  • The oil filter assembly (100) is missing, plugged, or damaged.
  • The oil filter seal assembly (101) is missing or damaged.
3-4 Accumulator Assembly
  • Misassembled upside down 3-4 accumulator assembly
  • Damaged or missing 3-4 accumulator piston oil seal ring (427)
  • A damaged or missing 3-4 accumulator piston outer spring (423)
  • A stuck or binding 3-4 accumulator piston (428)
  • A damaged 3-4 accumulator piston cylinder (421) or O-ring seal (422)
Control Valve Body Assembly
  • Debris in the passages of the control valve body (301) or spacer plate and gasket assembly (396).
  • Misassembled 3-4 accumulator valve (339, 350, 351) line-up
  • Stuck or binding 3-4 accumulator valve (350)
  • Missing, damaged, or misassembled 3-4 accumulator valve spring (351) or retainer (314A)
Driven Sprocket Support Assembly, soft shift only
  • A missing or damaged fourth clutch orifice (607)
  • A damaged driven sprocket support assembly (609)
Fourth Clutch Assembly
  • Worn, damaged, or misassembled clutch plates (500-502)
  • A missing or not seated fourth clutch spring retaining ring (601)
  • A damaged spring assembly (602) or piston (603)
  • Worn or damaged fourth clutch piston seals (604, 605)
2-3 Accumulator Cut or damaged 2-3 accumulator piston seal (137B)