Usage:
3408 and 3412 Engines in All Applications
Description of Change: The pressure oil passage from the cylinder block to the flywheel housing is no longer used on 3408 and 3412 Engines. This change was made to stop oil leakage at the junction of the cylinder block and the flywheel housing. The oil passage in the cylinder block now has a plug at the rear end and the flywheel housings no longer have an oil passage.
This oil passage was formerly used to send lubricating oil to the BrakeSaver and the air compressor on truck engines, the sleeve bearing of the transmission oil pump on 988 Loaders, and the air compressor on 631, 633, and 637 Tractors. The lubricating oil for the BrakeSaver, air compressor, and gear train will now come from oil passages on the right or left side of the engine block as follows:
Truck Engines
Lubricating oil for the air compressor now comes from an oil passage on the right side of the cylinder block. For the BrakeSaver, the lubricating oil now comes from an oil passage on the left side of the engine. Hose assemblies are used to connect the oil passages to the air compressor and the BrakeSaver.
The cooler bonnet was changed to give enough clearance for the hose assembly to the air compressor.
988 Loaders
On 988 Loaders, the former flywheel housing used an internal oil passage to send lubricating oil to the sleeve bearing for transmission oil pump. Now, lubricating oil for the sleeve bearing comes from an oil passage on the right side of the engine. From this passage, the oil flow goes to an existing hole in the top of the housing. If a machine in the field is changed to use the new oil line, remember to plug the former lubricating oil passages in the flywheel housing and the cylinder block.
Location of plugs installed in cylinder block and flywheel housing on 988 Loader.
631, 633 And 637 Tractors
Lubricating oil for the air compressor now comes from an oil passage on the right side of the cylinder block.
All Models
The oil passage in the cylinder block is now sealed at the rear end with a plug.
Adaptable To: Earlier engines when the new parts shown in the charts are used together.
