I have a cat 30 and was looking to some insight on the fan, I was running it and heard a noise so shut it off and found the fan hitting the radiator core. Removed the radiator to inspect and found everything seems tight. I can’t seem to locate the books for this and was wondering if there’s an adjustment or any kind of insight on this
 

No adjustment that I can recall -
Fan is gear driven bearings in the timing gear case.
It has been well over 50 years since I was in the fan assembly.
While you have the fan assembly open, be sure to check the friction plates, the fan sometimes slips from wearing these plates, they are held tight by a spring if memory serves.
Check that before you pull the rest of it apart.

I have seen many radiators damaged by the fans!

CTS

I had a RD 6 that rubber spacer or maybe the rubber is to help limit shock loading, anyway rubber fell apart, and fan hit the core make a big mess of it. Your 30 is about the same vintage. So maybe what is going on with yours.

In reading this thread I believe I found out what that hand full of wired together rubber pre-drilled (gaskets?) are. In other words I might have just what you need. I will try to find them today. Would they be the same size as a Diesel 40? I have a 40 here to compare it to.

I found ten 3B8676 (spacers?) that matches various CAT fan blades here. Total. 7 1/4" Dia. X 1/2" thick. 8 outer holes, 6 inner holes. PM me if interested.

I was thinking it would be a bearing failure but everything looks as it should so far not seeing anything that would have caused it to hit the radiator 

Cody,
As I suggested, check that fiber washer/friction disc just behind the fan blades.
The fan slips over time and wears that away, changes the clearances.

Try to find a schematic of the fan assembly/parts book, etc.

CTS

There are no rubber discs on a cat 30. Just two relatively thin friction discs.

That’s where I’m going next just wanted to share some pictures…I wanted to check the bearings aswell just to have peace of mind and not go into it twice…I’m looking for the books my grandpa had on it to find the diagram for it but I’m still looking for them. I feel like there should be a bit holding spring tension on there but not sure there wasn’t one there when I disassembled it