DETROIT DIESEL 53
Install Fan, Hub and Adjusting Bracket
New .500 " thick and .800 " thick fan hub spacers and a new fan hub cap replaces the former spacer and cap assemblies
to provide spacers compatible with the six bolt hole mounting fan hub assemblies. The spacers (individually or in
combination) also provide a means for setting the different clearances between the back of the fan blades and front
groove of the crankshaft pulley.
The new spacers have a flange on one side that serves as a pilot for the fan as well as a spacer pilot for the second
spacer when two or more spacers are used together.
EXAMPLE: A former 1.800 " thick spacer and cap assembly have been replaced by two .500
" thick spacers, one .800 " thick spacer and the new fan hub cap.
When replacing the former fan hub spacer be sure and include the new cap.
1. Attach the fan hub and adjusting bracket assembly to the bracket support on the engine with bolts, lock washers and
plain washers. Do not tighten the bolts.
2. Install the drive belts and adjust the belt tension as outlined in Section 15.1. If used, install the adjusting bracket,
bolt and plain washer shown in Fig. 10.
3. Install the fan (and fan spacer and cap, if used) on the hub and secure it with the 5/16 "-18 bolts and lock washers.