Grinding Noise from the NLG during Taxiing or Towing (Trouble Shooting procedure Weight on Wheels)

TASK 32-20-00-810-801-A-01
Grinding Noise from the NLG during Taxiing or Towing (Trouble Shooting procedure Weight on Wheels)

1. Possible Causes

nose wheel steering cylinder
shock absorber
LEG ASSY-NLG [2526GM]

2. Job Set-up Information
A. Consumable Materials

REFERENCE	DESIGNATION
(Material No.02BBB9)	Mineral Hydraulic Fluid-Damper - -

B. Referenced Information

REFERENCE	DESIGNATION
AMM 12-22-32-640-002	Lubrication of Nose Landing Gear and Doors
AMM 32-21-00-200-003	Check of NLG Torque Links for Excessive Play
AMM 32-21-00-200-004	Inspection/Check of the Clearance of the Nose-Gear Hinge Bearings
AMM 32-21-11-000-002
AMM 32-21-11-400-002
AMM 32-21-13-000-001	Removal of the NLG Shock Absorber Assy
AMM 32-21-13-400-001	Installation of the NLG Shock Absorber Assy
AMM 32-51-00-720-003	Functional Test of the Nose Wheel Steering with the Handwheel
AMM 32-51-42-000-001	Removal of the Nose-Wheel Steering Cylinder
AMM 32-51-42-400-001	Installation of the Nose-Wheel Steering Cylinder
Location of the Fluid Injection Method (Absorber Assy - NLG Shock)

3. Fault Confirmation
Subtask 32-20-00-700-051-A

A. Not applicable.

4. Fault Isolation
Subtask 32-20-00-810-051-A

A. If there is a grinding noise from the NLG during taxiing or towing

NOTE: The noise is because there is not sufficient lubrication in the shock absorber.This condition does not have an effect on safety.If it is not possible to do the lubrication procedure immediately (because there is not sufficient time or equipment),do it at the first opportunity.

add half a liter of hydraulic fluid Mineral Hydraulic Fluid-Damper - - (Material No.02BBB9) through the upper orifice of the leg on the internal wall of the barrel with a syringe so that the fluid runs down to the Airflon coated ring
Location of the Fluid Injection Method (Absorber Assy - NLG Shock)
operate the nose wheels AMM 32-51-00-720-003
(rotation of the shock absorber plus or minus 45 degrees)

NOTE: One lubrication is not always sufficient to stop the noise. Do the lubrication procedure again if the noise continues. It is usually sufficient to do the lubrication procedure 2 or 3 times to stop the noise.

NOTE: After this lubrication procedure ,it is possible that there will be too much fluid in the NLG shock absorber.This fluid will come out from the upper orifice of the leg when the NLG is retracted ,and flow on the NLG barrel and on adjacent area.It is necessary to do a check of the area after the subsequent NLG retraction or flight cycle and clean it if necessary.

(1) If the fault continues:

do the lubrication of the NLG AMM 12-22-32-640-002.

(2) If the fault continues:

do the inspection/check of the torque link assembly of the nose landing gear AMM 32-21-00-200-003.

(3) If the fault continues:

do the inspection/check of the clearance of the nose gear hinge bearings AMM 32-21-00-200-004.

(4) If the fault continues:

replace the nose wheel steering cylinder AMM 32-51-42-000-001 and AMM 32-51-42-400-001.

(5) If the fault continues:

replace the shock absorber AMM 32-21-13-000-001 and AMM 32-21-13-400-001.

(6) If the fault continues:

replace the LEG ASSY-NLG [2526GM] AMM 32-21-11-000-002 and AMM 32-21-11-400-002.

[Rev.8 from Aug 2018] 2026.04.04 04:31:18 UTC