641 Loose Fan Hub

[MikeC]

Hello,
The fan hub on my 641 is loose. I can grab a blade tip and move the blade and hub back and forth. There is no coolant leakage. Is this the water pump or something in the fan hub only?

TIA for any help.

 

[john_Bud]

Where is the wiggle originating? It sounds like water pump to me, but it's hard to see from this angle

jb

 

[john in la]

While it is hard to see from this angle I can say you need a new water pump.

Since the blade and hub are moving as one we can assume the 4 bolts on the fan are tight. So that leaves a loose or worn hub shaft fit; or more likely a worn bearing in the pump.
Either case means it is new water pump time.

 

[MikeC]

The water pump does not move. Onlt the fan blade and hub. The fan blade and hub are ridgidly attached to each other. Does a new pump come with the fan hub, or is it a separate piece?

MC

 

[NWMO 901 SOS]

(quoted from post at 12:45:29 08/30/09) The water pump does not move. Onlt the fan blade and hub. The fan blade and hub are ridgidly attached to each other. Does a new pump come with the fan hub, or is it a separate piece?

MC

Mike,

I've not worked on the water pump on my tractor, but if it is like the automotive engines (and I am sure it is), the fan blade and hub are separate pieces that bolt on to the water pump. Therefore, a new pump does not include the hub or fan.

Chris

 

[GlenIdaho]

Check the link below. Scroll down and you'll see two different water pumps listed. One has a removable hub and the other is not. Compare the pictures. Yours should be the second one listed.
Water Pump

 

[john in la]

Ford used 2 differant water pumps.

One has a long nosed pully

https://www.link_disallowed/acatalog/CDPN8501C.jpg

that is mounted to the shaft with a C clip.

The other is more like a car pully and is held on with the same bolts that hold on the fan.

https://www.link_disallowed/acatalog/DCPN8501A.jpg


In either case if you can move the fan and pully as one and the 4 bolts are tight your water pump is bad.

 

[MikeC]

I have the one on top. When I tried to remove the pump, I found that a 1/2" socket or box end wrench will not clear the side of the pump housing. A 1/2" open end will fit, but there is no room to turn the wrench. Any suggestions? Special wrench perhaps?

 

[GlenIdaho]

Hey Mike and Chris;

I took a look at my water pump and it appears that the hub is pressed on to the water pump shaft. I was expecting a bolt would hold the hub on, but nope, that's not the way it works. It's new water pump time.

 

[john in la]

Glen;
I do not think I have ever seen a water pump where the pully is truely bolted on. This would have to be like the balancer on the front of a crank shaft where the bolt went into the end of the shaft to be true.

Now look at the bottom water pump in the picture above. Yes the pully and fan bolt to the water pump via 4 bolts but does it really bolt to the pump shaft or rather to a piece that is pressed on the end of the shaft.

The top pump above most likely has a looser fitting pully because it needs a C piece to hold it on the shaft but it still has a press on fit.

Even if the problem was not the bearings in the pump (but it most likely is) that would mean the presision fit between the press on piece and the shaft is worn so a new pump is in order.

 

[john in la]

No special wrench needed.

Have you tried a thinner wall socket. Might try a 3/8 drive or even a 1/4 drive socket to get to it if you do not have thin wall 12 point sockets.

 

[NWMO 901 SOS]

(quoted from post at 21:38:03 08/30/09) Hey Mike and Chris;

I took a look at my water pump and it appears that the hub is pressed on to the water pump shaft. I was expecting a bolt would hold the hub on, but nope, that's not the way it works. It's new water pump time.

Thanks for keeping me straight guys.

Chris