V-belt sheaves.

[Red Roundhead]

I am sure everyone knows this by now, but three of my farming friends were having the same problem last fall with old combines/choppers. So here is the answer; if you have anything driven by a v-belt, and it seems to always slip, even with proper tension and new belts, please look at the condition of the sheaves. Especially with cast iron, where the belt rides it will wear, which will decrease the amount of contacted surface area, which will of course slip under load. Take the pulley off and cut it smooth, being sure to retain the proper v angle. This will help. Yes, you will slightly change the operating circumference of the pulley, and thereby your speeds. If you are very rich, buy new pulleys. I see this happen alot on water pumps too. I found it funny that a bunch of us were suffering from the same fate!

 

[msb]

Tractor engine sheaves are particulary prone to do this. Doesn't take long with working in dirt and dust.

 

[Fern(Mi)]

You've just proven an old man isn't to old to learn. Thanks
Fernan

 

[greenbeanman in Kansas]

"Tractor engine sheaves are particulary prone to do this."

Replacements are not cheap either. I think the one for my tractor was around $300 some 25-30 years ago.

 

[buickanddeere]

Certainly a valid point missed by 99% of belt replacers and tighening adventures.
Price pulleys before taking all the time to re-work them. Sometimes new costs less than the time and running around messing with old worn junk.