GM 6L80/90 FLARE 2-3 AND OR ENGAGEMENT CONCERNS
Complaint:
GM vehicles equipped with the 6L80/90 transmission, built prior to December of 2008 may exhibit a complaint of a flared 2-3 up-shift or a delayed with harsh application into Forward and/or Reverse engagements. Note: this complaint has been linked more to a cold condition but may show up at any time.
Cause:
The cause may be leakage in the sealing ring area on the pump cover which feeds the 1-2-3-4 and 3-5-Reverse Clutch packs, causing a slow application, which can also cause elevated pressure as the TCM may try to adjust for the slow application.
Correction:
To correct this condition, replace the previous design pump cover with the one piece sealing rings with the new two piece design pump cover with anti-rotational tab rings. A machining process was performed on this new pump cover to the ring land so as to accommodate the new anti-rotational tabs on the sealing rings. Note: This two piece sealing ring design was updated to prevent leakage in the 1-2-3-4 and 3-5-Reverse Clutch apply circuits and will retro-fit to previous models as a complete assembly. See the mandatory pump alignment ring that must be used when replacing the pump cover. Torque the 13 oil pump cover retaining bolts to 11 Nm (97 in.lb.).
Service Information:
PUMP COVER 2 PIECE SEALING RING DESIGN — 24248573
(New cover comes with rings already installed)
NOTE: This pump cover is also available from aftermarket sources.
MANDATORY PUMP ALIGNMENT TOOL
Adapt-A-Case Pump Alignment Tool — T46664AC
Or
Arizona Transmission Machine Inc. — 6061 T-6 Billet Aluminum
Or
GM Too — J-46664
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