Transmission and drivelineModel years 1999–2019Manufacturer
Grind / ratchet noise when shifting into Park in 4LO (characteristic)
GMC Yukon Models 1999 - 2019; light duty trucks with automatic transmission and 4 wheel drive
FaultCrate・Grind / ratchet noise when shifting into Park in 4LO (characteristic)
The grind/ratchet noise lasts approximately one second.
Light duty trucks with automatic transmission and 4 wheel drive may make a grinding/ratcheting noise when the transmission is shifted into park while the transfer case is in 4 wheel drive low (4LO) range.
In 4LO the gear reduction makes the transmission output shaft turn faster than the parking pawl will hold.
When the transmission is shifted from drive or reverse into park with the transfer case in 4LO, the driveline unloads and turns the propeller shaft approximately 1/8 of a turn.
What to do
No technical document states a check or a repair.
What is needed
- Parts and materials
- Not stated
- Labor time
- Not stated
- Special tools
- Not stated
- Scan tool
- Not stated
Only what the technical documents state. "Not stated" does not mean not needed.
If left
- The condition should be considered characteristic of 4 wheel drive vehicles operated in 4LO.
Caution
- Replacing transmission, transfer case or driveline components will not resolve the concern.
- Replacing transmission, transfer case and/or driveline components will not resolve the concern; shifting into park with the transfer case in the 4HI or 2HI range is recommended.
Applies to
- The bulletin lists GMC Yukon Models 1999 - 2019.
See the evidence (2 documents, 8 passages)
| Document | Publisher | Date |
|---|---|---|
| [1]PIP3366C: Grind/Ratchet Noise Occurs When Shifting Into Park While In 4 Wheel Drive Low ↗ | ManufacturerGeneral Motors (published by NHTSA) | 2018-07-09 |
| [2]PIP3366C Grind/Ratchet Noise Occurs When Shifting Into Park While In 4 Wheel Drive Low ↗ | ManufacturerGeneral Motors | — |
Applies toThe bulletin lists GMC Yukon Models 1999 - 2019.
GMC Yukon Models 1999 - 2019 All All All All— [1] Models
Why it happensIn 4LO the gear reduction makes the transmission output shaft turn faster than the parking pawl will hold.
The gear reduction in the transfer case causes the transmission output shaft to turn at a greater speed than the automatic transmission parking pawl will hold.— [1]
First signsThe grind/ratchet noise lasts approximately one second.
The grind/ratchet noise will last approximately one second.— [1]
What it does not lead toThe condition should be considered characteristic of 4 wheel drive vehicles operated in 4LO.
This condition should be considered characteristic of 4 wheel drive vehicles operated in 4LO.— [1]
CautionReplacing transmission, transfer case or driveline components will not resolve the concern.
Replacing transmission, transfer case and or driveline components will not resolve the concern.— [1]
First signsLight duty trucks with automatic transmission and 4 wheel drive may make a grinding/ratcheting noise when the transmission is shifted into park while the transfer case is in 4 wheel drive low (4LO) range.
Light Duty Trucks equipped with automatic transmissions and 4 wheel drive may exhibit a condition of a grinding/ratcheting type noise when shifting the automatic transmission into park while the transfer case is in 4 wheel drive low (4LO) range.— [2]
Why it happensWhen the transmission is shifted from drive or reverse into park with the transfer case in 4LO, the driveline unloads and turns the propeller shaft approximately 1/8 of a turn.
When the automatic transmission is shifted from drive or reverse into park with the transfer case in 4LO the driveline unloads and turns the propeller shaft approximately 1/8 of turn.— [2]
CautionReplacing transmission, transfer case and/or driveline components will not resolve the concern; shifting into park with the transfer case in the 4HI or 2HI range is recommended.
Replacing transmission, transfer case and or driveline components will not resolve the concern. It is recommended to shift into park while the transfer case is in the 4HI or 2HI range.— [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.
- Light Duty Trucks: Grinding Noise in Park with 4WD LowManufacturer communication 2018-08-20・document number matches