I have my coach in the local CAT service center 5 minutes from my house getting some things replaced.
During an inspection they found that the fan had a cracked blade almost ready to break off. It is a 28" counter clockwise fan made of nylon. CAT was having a difficult time finding one so I started looking online.
I got the part number from the assembly and finally found a fan.
Superior Turbo and Injection
3745 Central St.
Detroit, Michigan
48210
Superiorturbo.com
313-842-4616
They carry several different fans and also turbo assemblies.
Ordered the fan for $100 and $27 shipping.