Transmission and drivelineModel years not statedManufacturer
4L60-E / 4L65-E clunk on 2-3 upshift or 3-2 downshift (normal condition)
2014 and prior GM passenger cars and light duty trucks equipped with 4L60-E, 4L65-E or 4L70-E (RPOs M30, M32, M70); 2005 model year fullsize utilities and pickups are referred to bulletin 05-07-30-012
FaultCrate・4L60-E / 4L65-E clunk on 2-3 upshift or 3-2 downshift (normal condition)
Some vehicles may have a clunk noise on a 2-3 upshift or a 3-2 downshift.
On a 2-3 upshift the 2-4 band releases and the 3-4 clutch applies; the shift timing can cause a momentary torque reversal of the output shaft that results in a clunk.
It may be more pronounced on a 4-wheel drive vehicle because of the additional tolerances in the transfer case.
The same torque reversal can occur on a 3-2 downshift, when the 3-4 clutch is released and the 2-4 band applied.
What to do
No technical document states a check or a repair.
If left
- This is a normal condition and no repairs should be attempted.
Caution
- For 2005 model year fullsize utilities and pickups, refer to bulletin 05-07-30-012.
Applies to
- The bulletin covers 2014 and prior GM cars and light duty trucks with the 4L60-E, 4L65-E or 4L70-E.
See the evidence (1 documents, 7 passages)
| Document | Publisher | Date |
|---|---|---|
| [1]01-07-30-042H: Information on 2-3 Upshift or 3-2 Downshift Clunk Noise ↗ | ManufacturerGeneral Motors (published by NHTSA) | 2014-01-14 |
Applies toThe bulletin covers 2014 and prior GM cars and light duty trucks with the 4L60-E, 4L65-E or 4L70-E.
2014 and Prior GM Passenger Cars and Light Duty Trucks Equipped with 4L60-E, 4L65-E or 4L70-E Automatic Transmission— [1] Models
CautionFor 2005 model year fullsize utilities and pickups, refer to bulletin 05-07-30-012.
For 2005 model year fullsize utilities and pickups, refer to Corporate Bulletin Number 05-07-30-012.— [1]
First signsSome vehicles may have a clunk noise on a 2-3 upshift or a 3-2 downshift.
Some vehicles may exhibit a clunk noise that can be heard on a 2-3 upshift or a 3-2 downshift.— [1]
Why it happensOn a 2-3 upshift the 2-4 band releases and the 3-4 clutch applies; the shift timing can cause a momentary torque reversal of the output shaft that results in a clunk.
During a 2-3 upshift, the 2-4 band is released and the 3-4 clutch is applied. The timing of this shift can cause a momentary torque reversal of the output shaft that results in a clunk noise.— [1]
Why it happensIt may be more pronounced on a 4-wheel drive vehicle because of the additional tolerances in the transfer case.
This condition may be more pronounced on a 4-wheel drive vehicle due to the additional tolerances in the transfer case.— [1]
What it does not lead toThis is a normal condition and no repairs should be attempted.
This is a normal condition. No repairs should be attempted.— [1]
Why it happensThe same torque reversal can occur on a 3-2 downshift, when the 3-4 clutch is released and the 2-4 band applied.
This same torque reversal can also occur on a 3-2 downshift when the 3-4 clutch is released and the 2-4 band applied.— [1]
Put together by FaultCrate from public records and technical documents. The cause and the repair are for the workshop to decide with the vehicle in front of it. Counts are records, not failure rates.
List the records (1 that can be opened)
Records whose recall number, document number or text matches. Each line says why it matched.
- 2-3 Upshift and 3-2 Downshift Clunk Normal ConditionManufacturer communication 2018-05-21・document number matches