I am writing this in hopes that it will help a fellow 5.9 Cummins owner that has the same problem of having the radiator fan cracked.
I have a couple 2001 Dodge duallie 3500 4x4’s that both had the same unfortunate problem of having the radiator fan blades crack off and wreak havoc on a lot of stuff including the radiator, when it sheared off going down the road. So, I did my homework investigating on finding either a replacement used or new. I hate to be the bearer of bad news but, you can forget about a new one because they no longer make them. The next alternative was to locate a used from someone either at a local salvage yard or internet. Let me start by saying trying to locate one these fans on these 5.9 Cummins is like trying to find hens teeth. Lol When you luckily do happen to find one the people that have them want an arm and a leg for them because, like the old saying goes its due to supply and demand. The cheapest one I could find was about $300 and the highest was around $700. I hate to say I was not going to invest in another used older one that will could simply due the same thing again, due to a bad design. My only other option was to try to find an alternate blade that would simply bolt up to the clutch fan, even with modification. Well with a lot of research I stumbled on an old thread by a gentleman stating he used a universal fan, Derale 20” steel fan part #17120, and had to just modify the center hole. I took the chance ordered one through Summit, which cost only $53.92. I was amazed in the price difference! When I received it I noticed that my original fan clutch would not go down on the new fan even with some milling in the center hole but, the four holes seemed to line up fine. I had to do the same trick the gentleman also did and bite the bullet and order an older fan clutch from a 1998 Dodge Cummins from Advance Auto part #215035 for $56.34 without tax. After all said and done and put back together it works great!! I pull small loads with an 8X16 trailer to a big one with a 34’ gooseneck and I have NO complaints. It keeps my motor cool just fine. So in conclusion, if you are trying to save a lot of money and are willing to do a little work, I strongly suggest this route to go!