Wheel Sensors, Rear - Scrape, Squeal Noises
90chevy13Number: 90-258-5
Section: 5
Date: May 1990
Corp. Bulletin No.: 065003
Subject: REAR WHEEL(S) SQUEAKY, SQUEAL, SCRAPE NOISE
Model and Year: 1990 M/L TRUCKS WITH 4WAL BRAKES
Some customers may comment of squealing or scraping sounds generated near the rear wheel(s) which may be exhibited only on turns. This condition can be caused by one or both of the rear wheel sensor reluctors contacting the tone wheel(s).
The rear wheel sensors are not adjustable, however a technician might achieve sufficient clearance between the sensor and the tone wheel to eliminate this condition by loosening the wheel sensor mounting bolts, lightly prying the sensor away from the tone wheel with a small screwdriver to remove any slack, and then re-tightening the bolts to 35 N-m (26 ft. lbs.).
If this is not effective the sensor must be replaced.
IMPORTANT: Light contact of the sensor reluctor to the tone wheel should not affect the durability of the tone wheel, and the tone wheel should not require replacement.
Figure 1:
Service Procedure: (Refer to Fig. 1.)
1. Remove rear wheel and tire assembly.
2. Remove brake drum.
3. Remove primary brake shoe. Refer to Hydraulic Foundation Brakes (Sec. 5A2 of the Light Duty Truck Service Manual).
4. Loosen sensor mounfing bolts (2).
^ With a SMALL screwdriver very lightly pry the sensor outward, away from the tone wheel, to remove any slack.
^ Tighten the mounfing bolts to 35 N-m (26 ft.lbs).
^ Install primary brake shoe. Refer to Hydraulic foundation brakes (sec. 5A2 of service manual X-9030).
^ Install brake drum.
^ Install wheel and tire assembly.
^ Road test vehicle to verify noise is eliminated.
^ If repair is successful skip steps 5 through 16.
5. If road test determines that the repair was not successful repeat steps 1-3.
6. Disconnect sensor wire electrical connector.
7. Disconnect sensor wire from the rear axle clips.
8. Remove sensor mounting bolts.
9. Remove speed sensor by pulling the wire through the hole in the backing plate.
10. Install new speed sensor (P/N 15649151-left rear sensor P/N 15649152-right rear sensor) and mounting bolts. Torque bolts to 35 N-m (26 ft.lbs.).
11. Install sensor wire to the rear axle clips.
12. Connect sensor wire electrical connector.
13. Install primary brake shoe. Refer to Hydraulic foundation brakes (sec. 5A2 of the Light Duty Truck Service Manual).
14. Install brake drum.
15. Install wheel and tire assembly.
16. Road test vehicle to verify noise is eliminated.
SERVICE PARTS INFORMATION
PART NUMBER DESCRIPTION QUANTITY MODEL
15649151 Left rear wheel 1 M/L
speed sensor
15649152 Right rear wheel 1 M/L
speed sensor
Parts are currendy available through GMSPO.
WARRANTY INFORMATION
For vehicles repaired under warranty use:
Labor Labor
Operation Description Time
T 8120 Reposition/Replace Rear Sensor (one) 0.8 hr
T 8121 Reposition/Replace Rear Sensor (both) 1.1 hr
NOTE: Labor operations are coded to base vehicle coverages in the warranty system.