High Pitched Whistle Noise On Turns - keywords fluid hose line power steering
| Subject: | High Pitched Whistle Noise On Turns |
| Models: | 2003-2006 Cadillac Escalade, Escalade ESV, Escalade EXT |
| 2003-2006 Chevrolet Avalanche, Suburban, Tahoe |
| 2003-2007 Chevrolet Silverado Classic |
| 2003-2007 GMC Sierra Classic |
| 2003-2006 GMC Yukon, Yukon Denali, Yukon XL, Yukon Denali XL |
| With 670 or 680 Gearbox or with Rack and Pinion Steering |
This PI is being updated to add model year and repair information. Please discard PIT3434C
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
Owners may state that there is a high pitched whistle noise coming from the steering while driving. This noise may be more noticeable on left or right hand turns. The noise may be caused by interaction with the fluid flow through the spool valve.
Note:: This information only applies to the 670 and 680 Gearboxes or with Rack and Pinion Steering. To properly identify a 680 gearbox the stubshaft housing will be attached with 4 mounting bolts, See Document ID # 725682. The 670 gearbox only has 3 mounting bolts that attach the stubshaft housing, See Document ID # 415118. To identify a 700 gearbox, the stubshaft is held in place by a threaded retainer and lock nut, See Document ID # 1551804.
Recommendation/Instructions:
An updated spool valve was implemented on August 31, 2005 for NEW production gear boxes and racks used only for NEW production vehicles, NOT SPO PARTS. To check a NEW production gear or rack to verify it has the updated spool valve, locate the label on the component and make sure the Julian date is 2435 or greater.
Example of label:
P15173571 TNG3145B6501 (The Julian Date on this unit is 3145, which is the 314th day of 2005)
When ordering a gear box or rack-n-pinion from GM SPO only remanufactured parts are available, NO NEW PARTS CAN BE ORDERED. The updated spool valve was also implemented into remanufactured gear boxes and racks. SPO Parts has mixed stock of parts with the old spool valve and new. Currently, there is no way to identify a component with the updated spool valve and the only repair would be to replace the gear box or rack. The only way to know for sure that the part has the updated spool valve is a gear box or rack off a stock unit that has a Julian date of 2435 or greater.
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.
