Fan pulley question

[Ian D]

Hi Folks
Can ayone help with this question please
During my slow rebuild I have just fitted a new fan pulley (TM Tractor Parts) the old one has a worn bearing and was leaking all the oil out as the rubber was missing.
When I tension the belt and tighten it up - the whole pulley and fan sits slightly down hill and not parallel with the crank pulley resulting in the belt being slightly out of line
If I tighten it up without the belt (no tension) it appears to sit correctly
Is there a particular technique to tightening this up to get it sitting correctly?
I have looked at another nearby tractor and the fan/pulley is also sitting slightly downhill too
I have inspected the front face of the mount on the timing cover and also the groove the rear nut sits in and neither seem to be worn?
Is this common due to the slide mount on the timing cover having no upper support?
Thanks
Ian
Scotland
UK

[Glen]

Hi,
Sorry to hear about what happened in Paris today.
If you are over tightening the belt that could cause a problem like that, maybe. The owner's manual for the 1955 Cub says 3/4 to 1 inch of looseness half way between the pulleys.
Also, the assembly can be crooked in the slot when it is loose, with the front low. You have to tighten the belt to the right tension and hold the front of the assembly up, so it is all straight, as you tighten the shaft in the nut. Then it should be straight, and not low in the front.
Here are 2 pages from the Cub owner's manual telling about it. The belt tension picture is at the lower right of the first page.

http://www.cleancomputes.com/Cub/Cub%20 ... age-25.jpg

http://www.cleancomputes.com/Cub/Cub%20 ... age-26.jpg

[Ian D]

Hi Glen
Thank you very much for the reply much appreciated
I think after reading your post and refering to the 3/4"-1" of free play between pulleys I probably was trying to get the belt too tight.
I shall adjust and hold the fan up whuilst tightening it and see how it goes
Thanks again
Ian
Scotland
UK

[John *.?-!.* cub owner]

My system is to set it slightly loose, then as I tighten the bolt it raises the pulley and tightens the belt. That way only need 2 hands.

[Glen]

Hi,
I have used that way too, John, but I thought maybe it wasn't working for Ian for some unknown reason.
Ian, after looking at the pic again, I think you have too long a belt on it, the fan is up too high in the slots. The belts I have bought at the Case IH dealer make the fan shaft be a little below half way up the slots when the belt is new.

[Ian D]

Hello
Ok - thanks for that - I sat and studied this yesterday and worked out too that because the mount is part of the timing cover and has no upper support is has the potential to flex (very marginaly) forward when the belt is tensioned

I fully understand your comments regarding the belt length - I shall try another belt so it is positioned as you say about half way or just below and there will then be less chance of the mount flexing forward then

I guess this is maybe isnt the best piece of engineering IH produced!

Thank you once again for your help

Best regards
Ian

[Jim Becker]

That front cover is cast, it isn't going to flex. Running with the fan loose can cause wear to the uprights and the hardware which makes alignment more difficult. If the washer is worn, replace it.

You indicate the fan looks straight if installed without the belt. That pretty well says you are simply trying to get the belt too tight. Let the fan down just a little and the fan should pull into line as you tighten it. While the generator is off, you should be able to put a pinch bar over the generator bracket and under the fan retaining nut. Use it to pry the fan up then tighten the fan shaft. Don't go crazy prying on it.

[redman36]

Check to see if wide or narrow belt as there is 1 inch difference .How does belt ride in pulley ?If low you need wide belt. Been tripped by that.

[Ian D]

Ok - good thought
Thank you all
best regards
Ian