PIP3161H
Service Bulletin Details
Public Details for: PIP3161H
Summary to be provided on a future date.
- 9999 -
Models from 9999
9999 GMC GENERAL MOTORS |
File in Section: Service Bulletin Bulletin No.: Date: PIP3161H December, 2014 PRELIMINARY INFORMATION Subject: Allison LCT1000 Clunk When Shifting Into Or Out Of Park or On Start Up In Park Models: 2003-2009 Chevrolet Kodiak C4500, C5500 2001-2007 Chevrolet Silverado Classic 2007-2015 Chevrolet Silverado 2001-2007 GMC Sierra Classic 2007-2015 GMC Sierra 2003-2009 GMC TopKick C4500, C5500 Equipped with a Allison LCT1000 Transmission This PI was superseded to update Model Years. Please discard PIP3161G. The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI. Condition/Concern Customer may comment that trucks equipped with the Allison LCT1000 transmission may experience a clunk type noise on start up with the vehicle in park. Customers may also experience a clunk noise when shifting into park from reverse or a drive range or when shifting from Park into Reverse The condition may be intermittent. Customers may also comment that when shifting into and out of park repeatedly without releasing the brake pedal the clunk into Park or into Reverse will become more frequent and repeatable. The noise is a result of internal transmission clutch drag which is sufficient enough to load the output planetary carrier. The resultant load on the output planetary carrier can result in park pawl gear tooth impact against the park pawl and cause the clunk noise. The magnitude of the noise is dependent on the position of the park pawl gear relative to the park pawl. Recommendation/Instructions This condition is considered to be an operating characteristic of the Allison LCT1000 transmission Repairs or replacement of the transmission will not correct this condition ADDITIONAL SI KEYWORDS: None Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.