# Lubricating the needle bearings

## Preliminary requirements

### Support equipment

| Nomenclature | Identification No. | Qty |
| ------------ | ------------------ | --- |
| Grease gun   | Commercial         | 1   |

### Consumables, materials and expendables

| Nomenclature | Identification No. | Qty |
| ------------ | ------------------ | --- |
| Grease       | C-172              | AR  |

### Safety conditions

{% hint style="warning" %}
MAKE SURE TO OBEY ALL THE GREASE LUBRICATION PRACTICES BEFORE YOU LUBRICATE THE COMPONENT WITH GREASE. IF NOT, DAMAGE TO THE COMPONENT CAN OCCUR.
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## Procedure

{% hint style="warning" %}
DO NOT APPLY THE GREASE QUICKLY. APPLY THE GREASE QUICKLY CAN CAUSE PRESSURIZATION OF THE GREASE CAVITIES AND THAT CAN RESULT IN: PUSHING THE GREASE THROUGH THE SEAL, POPPING OR PUSHING OUT THE SEALS, DAMAGE TO THE SEALS, OR OTHER UNWANTED EFFECTS.
{% endhint %}

{% hint style="info" %}
&#x20;Rotate the tail rotor as necessary for access to lubrication fittings.
{% endhint %}

1. Lubricate the needle bearings of the tail rotor hub assembly as follows:&#x20;
   1. Refer to the grease lubrication practices.
   2. Slowly put grease (C-172) into the lubrication fitting, with a grease gun, until all of the old grease is fully replaced. Collect and discard the old grease when it comes out of the bearing.
   3. Turn the tail rotor 180°.
   4. Slowly put grease (C-172) into the opposite lubrication fitting, with a grease gun, until all of the old grease is fully replaced. Collect and discard the old grease when it comes out of the bearing.&#x20;
   5. Clean the area.
