Struts - Vehicle Pulls/Leads Left or Right
File In Section: 3 - Steering/SuspensionBulletin No.: 83-30-05
Date: October, 1998
Subject:
Vehicle "Pulls/Leads" Left or Right (Rotate Strut Assembly's Upper Spring Seat)
Models:
1991-96 Buick Park Avenue, Park Avenue Ultra
1992-98 Buick LeSabre
1991-96 Oldsmobile Ninety Eight
1992-98 Oldsmobile Eighty Eight, LSS, Regency
1992-98 Pontiac Bonneville
Condition
Some customers may comment that the vehicle "pulls or leads" left or right. Inspection shows the alignment to be within specification.
Cause
A "pull" or "lead" may be caused by excessive spring side load. This condition is due to the spring forces turning or twisting the strut relative to the strut mount. These spring forces are the result of the strut assembly being mounted off-center from the steering knuckle.
This condition may also be caused by uneven height between the two strut towers, or a combination of the two conditions.
Important:
Leads and pulls are terms for the same condition with different levels of severity. "Lead" refers to the path deviation of the vehicle from a straight path on a level road, without hand pressure on the steering wheel. "Pull" refers to the torque that is required at the steering wheel to maintain a straight path.
Correction
Important:
Correcting this condition by shimming the strut mount is to be DISCONTINUED immediately.
Tools and equipment required for this correction are as follows:
^ J 3289-20 Holding Fixture
^ J 34013-B Strut Compressor
^ Vehicle Lift
Important:
Eliminate all other possibilities for a lead or a pull. Refer to the vehicle's Leads/Pulls Diagnostic Information and Procedure Table in the Suspension - General Diagnosis section of the Service Manual.
If the wheel alignment is recent and the results are acceptable, perform the following procedure:
1. Verify "cold" tire pressure as per the Tire-Loading Information label located on the rear edge of the driver's door.
2. Check the condition of the tires. Refer to the Suspension - General Diagnosis section of the Service Manual.
3. Road test vehicle for a sufficient distance on a known smooth road surface to duplicate the condition. This should be done after a tire break-in of at least 10 miles (16 km) at 45 mph (73 km/h) or greater, to eliminate any possible tire flat-spotting.
Important:
Confirm that condition is not torque steer, memory steer, bias steering rack characteristics or brake drag.
4. If a road test indicates a "pull or lead" (to the left or right) still exists, go to Step 5.
5. This procedure requires that both left and right front strut assemblies must be adjusted. Remove the strut assemblies. Refer to the Strut Replacement Removal Procedure in the Front Suspension section of the Service Manual.
Notice:
Care should be taken to avoid chipping or cracking the spring coating when handling the front suspension coil spring. Failure to observe this notice may result in spring breakage.
6. In order to compress the spring in the strut assembly, install the strut (see Figure 1, Item 1) into the Strut Compressor Tool, J 34013-B.
^ Tighten the nuts (see Figure 1, Item 2) flush with the Strut Compressor Tool.
^ Install the locking pins (see Figure 1, Item 4) through the strut.
^ Mark the orientation of the spring relative to the strut.
^ Turn the Strut Compressor Tool Forcing Screw (see Figure 1, Item 3) until spring compresses enough so that the upper spring seat can be rotated.
^ Refer to Figure 3 for front strut assembly component identification.
7. For "lead or pull" conditions to the right:
^ Rotate upper spring seat clockwise 20 to 25 degrees, or about 2.5 cm (1 in.).
For "lead or pull" conditions to the left:
^ Rotate upper spring seat counter clockwise 20 to 25 degrees, or about 2.5 cm (1 in.). See Figure 2.
Important:
Do not exceed the 25 degrees, or about 2.5 cm (1 in.) when rotating the upper seat spring.
8. Turn the Strut Compressor Tool Forcing Screw (see Figure 1, Item 3) to remove the pressure on the strut spring.
9. Remove strut from the Strut Compressor Tool, J 34013-B.
10. Install the strut assemblies on vehicle. Refer to the Strut Replacement Installation Procedure in the Front Suspension section of the Service Manual.
11. Road test vehicle for a sufficient distance on a known smooth road surface to duplicate the condition.
Important:
It may be necessary to reset the alignment back to specifications.
Warranty Information
For vehicles repaired under warranty, use:
Labor Operation Description Labor Time
E3027 Springs, Front Coil 1.7 hrs
Both - Replace