BUSHING 3G8779 - Caterpillar

3406, 3406B and 3406C EnginesIntroduction
The 9Y5652 Inlet Adapter (cast iron) has been canceled and replaced by 4P2383 Inlet Adapter (cast iron).The 9Y5651 Impeller (cast iron) has been canceled and replaced by 9Y3778 Impeller (cast iron). The 4P2152, 1025941, 0R2856 and 0R3790 Water Pumps now use a 9Y3778 Impeller. The impeller part number is not visible when the impeller is installed in the water pump.When using the former 9Y5652 Inlet Adapter with these pumps, the clearance between the inlet adapter and the impeller vanes MUST be inspected for interference.There is a slight possibility of interference because of a difference in the profile of the vanes of the 9Y3778 Impeller compared to the 9Y5651 Impeller.Use the following procedures as a guide to inspect for interference before final installation.Clearance (Interference) Inspection
1. Set the water pump drive gear on blocks.If there is any end play in the pump bearings, the impeller vanes will be closest to the inlet adapter in this position.2. Install, temporarily, the 9Y5652 Inlet Adapter on the pump housing WITHOUT the adapter to pump housing O-ring seal. Make sure that the inlet adapter is fully seated.3. Rotate the pump housing and adapter.If there is any contact (interference) between the vanes of the impeller and the inlet adapter, it will be felt.If contact is felt, the 9Y5652 Inlet Adapter MUST be replaced with a 4P2383 Inlet Adapter.
If contact is felt, do NOT attempt to remove any material from the tips of the impeller blades.The impeller is balanced at the time of manufacture and any material removal will affect the balance and service life of the component(s).