Steering kickback (vibration)-electronic air

STEERING KICKBACK (VIBRATION)-ELECTRONIC AIR

Model

Range Rover

Affected vehicles

Electronic Air Suspension Derivatives

Date

1994-01-14

Reference

14/01/94

Bulletin text

SUBJECT Steering Kickback (Vibration) Electronic Air Suspension (EAS)

MODEL AFFECTED VEHICLES

Range Rover Electronic Air Suspension Derivatives

DETAIL

Prolonged steering wheel vibration over uneven road surfaces, after crossing a ridge or travelling on a poor condition road surfaces. The resultant action of the steering is that initial sudden steering movement does not cease after the first disturbance but is gradually damped out over a series of steering wheel movements, Typically four in quick succession. The steering wheel movement reduces in severity with each oscillation.

NOTE: This Bulletin replaces the previous Bulletins 012/93 and 126/93.

NOTE: Radius arm bushes NTC 6860 were introduced onto EAS vehicles at VIN LH 642119

ACTION REQUIRED

In the event of customer concern carry out the procedure detailed below.

PARTS INFORMATION

NTC 6860 Front radius arm bushes. STC 1473 Front shock absorbers. STC 1474 Rear shock absorbers. RTC 6825 Harmonic damper kit.

PROCEDURE

In the event of customer concern carry out the preliminary checks 1 to7.

NOTE: When replacing radius arm front bushes NTC 6781 with NTC 6860 the harmonic damper kit must also be fitted if not already fitted. (Note NTC 6860 have been fitted as standard on all EAS vehicles since VIN LH 642119). If the vibration still exists on vehicles fitted radius arm bushes NTC 6860, fit shock absorber kits.

Continued on following page....

14/01/94

57/02/94/EN

WARRANTY

Normal warranty policy and procedure applies.

COMP. CODE

5R1W Front shock absorbers Rear shock absorbers 5R5W

SRO

Procedure 1 only 57.10.30 road test and checks 01.20 hours Procedure 2 (includes procedure 1 time) 60.31.10 Road test, checks, fit harmonic damper and front and rear shock absorber kit.03.45 hours.

SUBJECT Steering Kickback (Vibration) Electronic Air Suspension (EAS)

MODEL AFFECTED VEHICLES

Range Rover Electronic Air Suspension Derivatives

Procedure 1 (Before any parts replacement)

1) Road test vehicle to confirm customers concerns. 2) Check tyre condition and pressures. 3) Check all steering and front suspension fixing torque values. Refer to the Workshop Manual sections 57, 60, 64. 4) Check and adjust front wheel balance. 5) Check front hub end float. Refer to the Workshop Manual section 54. 6) Check and reset steering box on centre position. 7) Re-assess vehicle, if the original concern still exists proceed as follows:

Procedure 2

8) Replace the front radius arm bushes NTC 6781 with NTC 6860. 9) Fit harmonic damper kit, if not already fitted. 10) Fit front STC 1473 and rear STC 1474 shock absorbers. 11) If it is necessary to adjust front hub pre-loads refer to section 57 of the workshop manual.

NOTE: Under no circumstances should the swivel pin pre-load be set higher than the recommended settings. Should the pre-load be set higher than that stated premature wear of the bearings will take place and steering feel will be affected. Refer to the Workshop Manual section 54.

Should steering kickback be evident after carrying out these checks, please submit a Product Report to Technical Service.

14/01/94 57/02/94/EN