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

WARNING: This page is about a different car, the 2006 Pontiac Montana SV6, 2006 Chevrolet Uplander, and 2006 Buick Terraza. However, it is still accessible from the selected car via links, so may be relevant.

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)