Chevrolet Silverado / GMC Sierra. Manual - part 808
TORQUE CONVERTER INSTALLATION AND HOLDING FIXTURE REMOVAL
(6L80/6L90)
Fig. 198: Torque Converter Installation and Holding Fixture Removal (6L80/6L90)
Courtesy of GENERAL MOTORS CORP.
Callout
Component Name
1
NEW Case Extension Seal
2
Case Extension
3
Bolts M10 x 40 (Qty: 6)
Procedure:
Tighten in sequence shown.
Tighten: 50 N.m (37 lb ft)
NOTE:
Refer to Fastener Notice .
Callout
Procedure
2008 Chevrolet Silverado 1500
2008 TRANSMISSION Automatic Transmission - 6L50/6L80/6L90 - Cab & Chassis Sierra, Cab & Chassis Silverado,
Sierra & Silverado
DEFINITIONS AND ABBREVIATIONS
THROTTLE POSITIONS
Engine Braking
A condition where the engine is used to slow the vehicle by manually downshifting during a
zero throttle coastdown.
Full Throttle Detent Downshift
A quick apply of the accelerator pedal to its full travel, forcing a downshift.
Heavy Throttle
Approximately 3/4 of accelerator pedal travel, 75 percent throttle position.
Light Throttle
Approximately 1/4 of accelerator pedal travel, 25 percent throttle position.
Medium Throttle
Approximately 1/2 of accelerator pedal travel, 50 percent throttle position.
Minimum Throttle
Preliminary Procedure:
Rotate the transmission so that the fluid pan assembly is down.
1
Transmission Case Assembly
Special Tools
DT 47605 Holding Fixture Adapter. See
Special Tools.
J 3289-20 Holding Fixture Base Assembly.
See Special Tools.
J 8763-B Holding Fixture. See Special
Tools.
2
Torque Converter Assembly
2008 Chevrolet Silverado 1500
2008 TRANSMISSION Automatic Transmission - 6L50/6L80/6L90 - Cab & Chassis Sierra, Cab & Chassis Silverado,
Sierra & Silverado
The least amount of throttle opening required for an upshift.
Wide Open Throttle (WOT)
Full travel of the accelerator pedal, 100 percent throttle position.
Zero Throttle Coastdown
A full release of the accelerator pedal while the vehicle is in motion and in drive range.
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.
2008 Chevrolet Silverado 1500
2008 TRANSMISSION Automatic Transmission - 6L50/6L80/6L90 - Cab & Chassis Sierra, Cab & Chassis Silverado,
Sierra & Silverado
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.
2008 Chevrolet Silverado 1500
2008 TRANSMISSION Automatic Transmission - 6L50/6L80/6L90 - Cab & Chassis Sierra, Cab & Chassis Silverado,
Sierra & Silverado