Tech Tip: Uncovering Cause of Crunching Noise During Low-Speed Turning

Tech Tip: Uncovering Cause of Crunching Noise During Low-Speed Turning

Some owners of GM vehicles may complain of a crunch and/or popping sound during low-speed turning. The lower control arm may be striking the steering knuckle during full-turn type maneuvers, causing the crunch sound. Slight movement between the steering gear attaching bolt threads and the frame rail inboard steering gear attaching holes may cause the popping sound ....

APPLICATION
GM power steering gears: 27-6535, 6560, 7525, 7547, 7549, 7561, 7562,7563, 7573 and 7583.

PROBLEM
Crunch and/or popping sound during low-speed turning.

CAUSE
The lower control arm may be striking the steering knuckle during full-turn type maneuvers, causing the crunch sound. Slight movement between the steering gear attaching bolt threads and the frame rail inboard steering gear attaching holes may cause the popping sound.

SOLUTION
Crunch Sound: Applying a light coat of grease on the control arm and knuckle where contact is made should reduce the noise.

Popping Sound: Examine the frame rail inboard steering gear attaching holes for evidence of bolt thread contact. Enlarge inboard mounting holes that show contact only enough to allow the bolt threads to be free in the frame holes (use appropriate tools for the job). Reinstall the gear, but do not tighten bolts 1, 2 and 3 (see figure 1). Then perform the following steps:
1. Start the vehicle and cycle the steering lock to lock several times, allowing the gear to reposition itself.
2. Torque attaching bolts (1, 2 and 3) to 70 ft. lbs. (95 Nm).

Please refer to the vehicle service manual for detailed gear removal and installation procedures.

Note: This Pro Tech bulletin is supplied as technical information only and is not an authorization for repair.

Tech Tip courtesy of CARDONE.

For additional information on products offered by CARDONE, visit www.cardone.com.

You May Also Like

Manual Transmission Failure Causes

One of the most common reasons behind why a manual transmission fails is lack of lubrication.

The most common reasons behind why a manual transmission fails are lack of lubrication, incorrect lubrication and improper or no clutch release.

COMPLEXITY OF LUBRICATION

Lubrication should be simple, but in the modern world NOTHING is simple. There was a time when virtually all stick transmissions ran on 90w gear oil. The synchronizer rings were brass or bronze, the cars and trucks shifted around 3,000 rpm and we had 3- and 4-speed transmissions. Ninety-weight did not like cold weather and generated multiple complaints to the manufacturer due to cold-shift problems. You needed two men and a boy to shift one of the units on a cold day until the fluid heated up.

Wheel Bearing Hub Damage Repair

Noise is a classic sign of a bad wheel bearing or wheel hub bearing. Determining why the damage happened may take some time.

Electric Vehicle Battery Service

Don’t be afraid to work on battery packs. However, you should be mindful of the potential damage high voltages can cause.

ADAS Suspension Alignments

Look at the “big picture” and really consider how the vehicle will operate if things aren’t done correctly.

Building The Perfect Future By Mentoring

Share your stories of how you have helped others reach their goals.

Other Posts

Electric Power Steering Diagnostics

Load management for steering systems.

GRI Receives US DOT Certification For Safety

GRI tires will now incorporate the DOT code emboss on its side walls.

Active Ride Control Diagnostics

The key to servicing these systems is proper information and understanding precisely how these systems operate.

Brake Pad Errors and Mismatches

In order to make the right selection, you must do your homework while still remaining skeptical.