Shift Condition Definitions

SHIFT CONDITION DEFINITIONS

Bump	A sudden and forceful apply of a clutch or a band.
Chuggle	A bucking or jerking. This condition may be most noticeable when the converter clutch is engaged. It is similar to the feel of towing a trailer.
Delayed	A condition where a shift is expected but does not occur for a period of time. This could be described as a clutch or band engagement that does not occur as quickly as expected during a part throttle or wide open throttle apply of the accelerator, or during manual downshifting to a lower range. This term is also defined as LATE or EXTENDED.
Double Bump - Double Feel	Two sudden and forceful applies of a clutch or a band.
Early	A condition where the shift occurs before the car has reached proper speed. This condition tends to labor the engine after the upshift.
End Bump	A firmer feel at the end of a shift than at the start of the shift. This is also defined as END FEEL or SLIP BUMP.
Firm	A noticeably quick apply of a clutch or band that is considered normal with a medium to heavy throttle. This apply should not be confused with HARSH or ROUGH.
Flare	A quick increase in engine RPM along with a momentary loss of torque. This most generally occurs during a shift. This condition is also defined as SLIPPING.
Harsh - Rough	A more noticeable apply of a clutch or band than 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, such as a 4-3-4 shift pattern. This condition is also defined as BUSYNESS.
Initial Feel	A distinctly firmer feel at the start of a shift than at the finish of the shift.
Late	A shift that occurs when the engine RPM is higher than normal for a given amount of throttle.
Shudder	A repeating jerking condition similar to CHUGGLE but more severe and rapid. This condition may be most noticeable during certain ranges of vehicle speed.
Slipping	A noticeable increase in engine RPM without a vehicle speed increase. A slip usually occurs during or after initial clutch or band apply.
Soft	A slow, almost unnoticeable clutch or band apply with very little shift feel.
Surge	A repeating engine related condition of acceleration and deceleration that is less intense than CHUGGLE.
Tie-Up	A condition where two opposing clutch and/or bands are attempting to apply at the same time causing the engine to labor with a noticeable loss of engine RPM.