[Frankie4Fingers]

Again, Richard encouraged me to take a deep dive and tackle a complicated project. Thank you Richard!

I removed my Multi-Wing Fan to re-pitch the blade angle. It’s also the perfect opportunity to clean the radiator/CAC/hydraulic cooler!

Read the Multi-Wing Fan instructions thoroughly!




My fan has eight Z6 blades that were set at 20° pitch. I am going to increase the blade angle to 32.5° in an effort to draw more air across the radiator stack. I hope this also helps move hot air out the back of the engine bay as well.

My Multi-Wing Fan was manufactured 5/26/04. 

I measured the diameter of the fan at 38”.

The blades are in good condition, I may consider replacing them in the future due to age. 

Tools used in removal:
The center bolt which holds the fan assembly to the shaft on the overhung load assembly requires a 1/2” wrench, the bolt has a thread of 5/16-24. I forgot to measure the bolt length.
 
The remaining hardware was removed with a 10mm wrench and socket. 




Removal:
The entire Multi-Wing Fan can be removed from the drive assembly by removing the center bolt that threads into the OHLA drive shaft (I noticed a coach with a C-15 did not have a OHLA but the motor appeared to be similar to my motor). 
I opted to leave the fan mounting flange attached to shaft by removing the five M6-1.0 bolts and lock nuts. I used a 1/8” ball rotary file in a Dremel tool to make a small mark on the flange and hub to ensure I re-assemble in the original configuration. Yes this created more work for me but I’m not familiar with a tapered key shaft assembly. As I mentioned, I did remove the bolt for a photo shoot opportunity then replaced it. 


Clearly, the left side of the engine compartment is tight quarters and removing the fan assembly is not a desirable job. I strongly suggest a long sleeve shirt for this job because it is necessary to reach your arm through the fan blades. They do have sharp edges. 
Patients is needed when loosening the bolts/nuts to remove the fan from the flange. I have an electric Milwaukee 3/8” ratchet that was very helpful. 

Once the fan assembly was free of the flange, I had to strap a coolant header tank hose out of the way and remove the CAC boot so the fan could slide out of the engine bay.


Once I had the assembly in the workshop and on a flat surface, it was photo shoot time. 
I took several pictures OF EVERYTHING to aid in re-assembly. On my fan two of the outer bolts had additional lock nuts (one a cap nut) added for balancing. 
I purchased new bolts and nuts and reassemble in the original configuration. 

The next step is identifying/marking all of the blades and hub/retainer configuration. 


The outer ring of bolts are the M6-1.0x25
The inner bolts are M6-1.00x16

TAKE MORE PHOTOS THAN YOU’LL EVER NEED. 

I used plastic pry tools to separate the hub and retaining rings. Do this step slowly because you want to note which “grove” the pitch locating pin is in the hub/retainer.


I determined the pitch of my blades were set at 20°. This is minimum pitch the fan can be set at. I honestly don’t know what to think of this setting. The Multi-Wing rep recommended I increased the pitch. Time will tell. 

I proceeded to clean up all of the parts for re-assembly making sure not to wash off the information I wrote on everything. 

I strongly suggest you study and inspect every component carefully. The manufacturer placed a locating triangle in the casting. It just so happened mine was at the 9 o’clock position when I started marking everything. Use the triangle to make sure the retainer and hub are re-assembled in the original configuration. 

Once I figured out where I needed to place the locating pin in the retainer ring for 32.5°, it was time to start the re-assembly process. 
I used clamps to hold the blades in the correct position as I placed the hub over the retaining ring. I used C-Clamps to hold the hub and retaining ring together. 



I’ll continue the assembly in the next post.

How did you get the fan motor to stay still while taking off the outside screw?  My blades are spinning free and need to be replaced but when I turn the screw on the outside, the motor turns and it doesn't loosen.