How tight is tight and how loose is loose
 

Hi guys . Could be a stupid question but here goes . How tight should the fan belt be? I have a 41 flathead and I hear differing options on how tight the belt should be. Too tight and the generator could get damaged . My gen has been re built and new water pumps and a new belt was put on about 6 months ago. At higher RPMs the gen makes a noise like a rusty machine type thing, at idle not a lot of noise but some . I have the correct belt. I took it to the re builder to check it out and he said that there is wear on the narrow part of the pulley ,he put it on his machine and said it was fine. He will pull it apart to make sure it’s all good .. but have I had this belt on too tight , how loose should it be? Thanks guys

Re: How tight is tight and how loose is loose
 

The belts only need to be tight enough to prevent slippage.

Re: How tight is tight and how loose is loose
 

Think 1/4" movement with a finger is considered about right. But as JSeery said.

Re: How tight is tight and how loose is loose
 

ive always been told 1" on the left side between the gen and water pump [history lesson i though it was to loose tightend it up and then promptly overloaded the water pumps and had to replace them ] if the belts noisy try rubbing the V with some hard bar soap works a treat

Re: How tight is tight and how loose is loose
 

https://www.earlyfordv8.org/forum/pr...18&Topic=10581


Post from len47merc about halfway down. 1/2".

Same as Old Henry - just with a screwdriver for me.

Regarding the belt deflection specification/tightness, I too always adjust mine as TomO states and have never had a problem or prematurely worn belt; however, Fig. 11 on Page P-4 of the 1942-1948 SHOP MANUAL shows 1/2" FREE MOVEMENT as the tightness setting. I typically tighten just to the point there is no excess belt movement at rpm which equates to approximately 1" deflection. You be the judge of what works best for you.

Steve


Don't think it would be much different for a 41. But someone will let me know I'm sure.

Re: How tight is tight and how loose is loose
 

Thanks guys good info for sure , I will make the advises adjustments once the gen is back. Is there anything I could apply to the belt to make it less noisy?

Re: How tight is tight and how loose is loose
 

A new belt adjusted properly should run quiet and shouldn't need anything added to it.
Ken

Re: How tight is tight and how loose is loose
 

My old man must not have been much good at adjusting belts, because he always had a tube of "Belt Dressing" available. He used it on his cars, the power saw, joiner, and drill press in his shop, as well as the riding lawnmower.:confused:

I believe that they made it back then because nobody replaced belts until they broke. Got a little slippage? Hit it with the belt dressing.

It must be good for something. a lot of companies (e.g. Grainger) still sell it.

Re: How tight is tight and how loose is loose
 

I have always adjusted mine to 1/2" deflection & used soap if noisy.

Re: How tight is tight and how loose is loose
 

Tub, when I was about 12 years old, my job was mowing our lawn. The belt on the mower looked like it needed some attention. I put motor oil on it....lesson for that day.....motor oil is not rubber belt dressing!!