Subject: | Noise During The 1-2 Shift When Cold |
Models: | 2009 Cadillac CTS-V - Tremec Transmission |
Equipped With Tremec Manual Transmission RPO Code MG9 |
2008-2009 Chevrolet Corvette, Corvette Z06 |
Equipped With Tremec Manual Transmission RPO Code MM6, MZ6 or MH3 |
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Some customers may comment about a Nibble or grate type noise that may also be described as a multiple bump feel during a 1-2 upshift event while the transmission is cold.
A new transmission synchronizer design was released for the 2008 and 2009 models listed above. The new synchronizer will make a noise when shifting from 1st to 2nd gear in temperatures at or below 32 degrees F.
This noise/feel is a normal characteristic and will go away after the transmission warms up. Warm up should occur after approximately 15 miles of normal driving. This condition requires no repair by the dealer.
The service technician should test drive the vehicle to verify the concern. If the noise/feel goes away after warm up no repair is necessary and the customer should be advised accordingly.
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.