Shift Conditions

Bump: A sudden and forceful engagement of a clutch or band.

Chuggle: A bucking or jerking that is most noticeable when the converter clutch is engaged. A Chuggle is similar to the feel of towing a trailer.

Delayed: A condition in which a shift is expected but does not occur for a period of time. Delayed is also defined as late or Extended.

Double Bump (Double Feel): Two sudden and forceful engagements of a clutch or a band.

Early: A condition in which the shift occurs before the car has reached the proper speed. The early condition tends to labor the engine after the upshift.

End Bump: A firmer feel at the end of a shift as compared to the feel at the start of the shift. End bump also is define as "End Feel" or Slip Bump".

Firm: A noticeably quick engagement of a clutch or band that is considered normal with a medium to heavy throttle. This should not be confused with Harsh or Troughs.

Flare: A quick increase in engine rpm along with a momentary loss of torque. This generally occurs during a shift. Flare is also defined as , Slipping.

Harsh (Rough): A more noticeable engagement of a clutch or a band as compared with "Firm". This condition is considered undesirable at any throttle position.

Hunting: A repeating quick series of upshifts and downshifts that causes a noticeable change in engine rpm. An example is a 4-3-4 shift pattern. Hunting also is defined as "Busyness".

Initial Feel: A distinct sturdy feel at the start of a shift as compared to the end of the shift.

Late: A shift occurs when the engine is at a higher than normal rpm for a given amount of throttle.

Shudder: A continuous jerking condition similar to "Chuggle" but more severe rapid. This condition is most noticeable during certain car speed ranges.

Slipping: A noticeable increase in engine rpm without a car speed increase. A slip usually occurs during or after the initial clutch or band engagement.

Soft: A slow, almost unnoticeable clutch or band engagement with very little shift feel.

Surge: A repeating acceleration and deceleration that is engine-related. This condition is less intense than "Chuggle".

Tie Up: A condition in which two opposing clutches and/or bands are attempting to engage at the same time, causing the engine to labor with a noticeable loss of engine rpm.