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II. Engine Component Description
Crankshaft
The crankshaft is forged steel with tufftrided
main and connecting rod journal surfaces.
Tufftriding is applied to the friction surfaces of
the journals, crank pins and oil seal surfaces to
improve wear resistance.
Each rod journal has its own set of counter weights to simplify balancing and help reduce
crankshaft vibrations. Certain 4IRJ7N engines are externally balanced with the use of weights
on the crankshaft damper.
NOTE: The dampers should NEVER be interchanged. Excessive
engine vibration and damage will occur.
IMPORTANT: The crank is hardened using Tufftriding. IR does not recommend
grinding or polishing the crankshaft undersize.
Removal of the rear oil seal is achieved with
the use of special tool 54368865.
The oil seal is a 360° style with an integral oil
slinger and presses onto the block.