DETROIT DIESEL 53
5.4
ENGINE COOLING FAN
The engine cooling fan is driven by a pair of V-drive belts from the crankshaft pulley (Fig. 1).
Effective with engine serial number 3D new fan hub assemblies are being used on the In-line engines. The new
assemblies are similar to the integral cast shaft and bracket design, with tapered roller bearings, currently used on the V-
type engines (Fig. 5).
The belt-driven fan is bolted to a combination fan hub and pulley which turns on a sealed ball bearing assembly (former
In-line engines) or two tapered roller bearings ( current In-line engines). The crankshaft driven fan is bolted to the
crankshaft
Lubrication
The sealed ball bearings, used in the fan hub assembly on the former In-line engines, is pre-lubricated and requires no
further lubrication.
The tapered roller bearings, used in the fan hub on current In-line engines, are pressure lubricated prior to assembly.
The cavity between the bearings is packed with Chevron BRB No. 2 grease or an equivalent performance grease at the
time the hub is assembled. Also the fan hub cap is packed approximately 75% full of grease. Repack the fan hub
assembly as outlined in the assembly procedure. The hub cap at the front and a seal at the rear of the hub prevents
leakage of the lubricant.
Remove Fan, Hub and Adjusting Bracket
The fan blades must rotate in a vertical plane parallel with and a sufficient distance from the radiator core.
Fig. 1. Belt-Driven Fan Mounting
July, 1972
SEC. 5.4
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