[jdkskyking]

Hello all watching this thread. I’m editing this thread to provide current context to my original thoughts and experiences. 
I hope I can save many of you thousands of dollars and hours of frustration by cutting to the chase. 

My coach was built 20 years ago. I have no expectations that twenty year old parts and engineering will be fully functional today however, the past five years have proven to be very frustrating and informative for my wife and I. We have replace almost every component of our suspension and ZF RAS system. We essentially have a new coach from the floor down, the top is still beautiful.

Recently I had a radiator and CAC change. That was accomplished at Newell, thank you Newell for helping me solve problems for my coach and hopefully many others. 

Changing out the CAC and radiator made a significant difference in how my engine performs but that didn’t solve the root case of the problem. I’ll get to that as well.

Recently I had an alignment performed that appears to have corrected all handling problems I’ve struggled with since I purchased #744 in late 2018 and took delivery in 2019. 

I’ll expand on my alignment solution in the thread I started on that topic. I’m a very “Happy Camper” in that category as well. 

Bottom line for my fellow Caterpillar owners, there are a few mechanical items that cause cooling and performance problems with our designs.
 
First and foremost, if you have a single V20 hydraulic pump supplying your ZF gearbox and hydraulic cooling fan motor, your engine will experience high coolant temps and ZF gearbox hydraulic flow and pressure problems. I’m sorry but this is a fact. I will debate this issue if necessary but several Newell Gurus have been along for my ride and understand the problems. 

Tips for success are simple. 
Replace the fan blades before they fail due to heat and age. 

Increase fan blade pitch. More to that than meets the eye. The V20 pump can only handle 2500 psi pressure demand. More to that as well. You fan is set at 20° pitch. You can increase to 27.5° to help airflow but you need to modify other systems to have a winning combination.

Get out ahead of high coolant problems before you overheat your engine. 

Cat 15 owners. Make sure your single V20 hydraulic pump has the proper pump and shaft to last long time. 

Now back to the original thread… 
Good luck! 



I’m exploring what options are available to improve airflow from my cooling fan. 

In my 2005 with a C13 ACERT, Newell installed a MULTI-WING Z Series Fan with “6Z” Blades. I have eight blades. 

I reached out to the U.S. Multi-Wing distributors and was contacted by:
(Larry Brudzynski has retired)

Superior Turbo and Injection. 
313-842-4616 Ext 604.

Larry asked me to send him pictures of my fan. He looked at the blade pitch and estimated the blades are currently set at 25°. He is recommending that I re-pitch the blades to 35°-37.5°. 

MW Z-FAN ASSY INSTRUCTIONS.pdf Size: 274.74 KB  Downloads: 26

Larry is very knowledgeable and helpful. He is a resource for information, parts, or a new fan if necessary.

I’ll provide updates as I continue my research. 

Take care, 
JK

[Richard]

Did you guys discuss fan rpm? Over the years this has been a topic of debate within the forum. Specifically how fast should the fan be turning at low and high speeds.

[jdkskyking]

I did explain my observations of the ratio between fan speed/engine rpm with my single hydraulic pump system and hydraulic manifold components.

Fan Low Speed is approximately one halve the engine RPM - Fan 12v DC Solenoid Energized).

Fan High Speed is approximately the same as engine RPM - Fan 12v DC Solenoid Not Energized (in this state, the spool valve shifts and all fluid flow goes to fan motor. The logic valve senses steering gearbox requirements and diverts flow accordingly).


I will have additional discussions about the fan and per his comments, the inability to exhaust heat from the engine compartment especially with the compound turbo charger setup.

[jdkskyking]

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!

Multi-Wing Z6 Instructions .pdf Size: 274.74 KB  Downloads: 3

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.

[Latitude 28]

Jeff,
Great write up!  Thank you..... I now have another project to investigate :-)

[BusNit]

Nice work! In looking at the original pitch, my seat of the pants engineering would think that was way too conservative of a pitch. Especially for a side load cooling system. Proud of you for tackling this. Definitely not a job for the faint of heart. Let us know how it performs and of course sounds. I imagine you would hear more air movement. On a side note, my only concern would be the age of the plastic fan blades and them now handling a slightly larger load. Not sure what new blades cost or of the company thinks they are good for life.

[Jack Houpe]

Can't wait to hear how it works out, looks like its in a tight spot to work if it were me I'd need a blood transfusion. Great Job!

[[email protected]]

The blades are looking old. I am surprised the rep didn't recemmend replacement.
I use Wing-Fan (interchangable with multi-wing) fans in my business.
attached is a comparison of the fans with angle change

   

[jdkskyking]

Nice work! In looking at the original pitch, my seat of the pants engineering would think that was way too conservative of a pitch. Especially for a side load cooling system. Proud of you for tackling this. Definitely not a job for the faint of heart. Let us know how it performs and of course sounds. I imagine you would hear more air movement. On a side note, my only concern would be the age of the plastic fan blades and them now handling a slightly larger load. Not sure what new blades cost or of the company thinks they are good for life.


New blades are $36 each. Yes I plan to replace them.
My VICKERS V20 pump is limited to 37 HP so pitch change makes a significant difference. Wing-Fan rep suggested 35°, he felt the same. His comment was nobody with a side radiator uses 20°. 
I’m going to re-pitch to a lesser degree, probably 25° until I can figure out more about what the higher pitch does to system load. As long as the fan speed is not in the high mode (high=fan rpm equals engine rpm), I think 25° or 27.5° will improve my situation. 
JK

[jdkskyking]

The blades are looking old. I am surprised the rep didn't recemmend replacement.
I use Wing-Fan (interchangable with multi-wing) fans in my business.
attached is a comparison of the fans with angle change

Gary,
I believe my maximum drive power is 37 HP. I’d be interested to know what the maximum pitch for that horse power is. In normal mode the fan rpm would not likely exceed 1100 rpm worse case scenario. 

If the engine calls for high the fan rpm could reach 2200 rpm at max engine rpm of 2200… not likely but who knows. 

Just noticed you show 28” for fan diameter. The fan is a 38” diameter on my setup.
JK