# Belt slippage I cant fix



## Smallfarmky (May 31, 2017)

I have a New Holland TN75DA and I can not seem to make the little ac belt not slip. Changed belt, tried one belt, tried Napa belt, used a bar to tighten belt, heck I even replaced the ac compressor. I can not stop the squeal for more then 30 mins at a time. Stupid question I know but anyone have any tips?


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## stack em up (Mar 7, 2013)

When you replaced the compressor, did you put on a new clutch? Had that happen on the planter Challenger this spring. Belt squealed like a pig constantly, threw a new clutch on and squealing pig left.


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## IH 1586 (Oct 16, 2014)

My NH TD95D has been doing this since last year. Will look forward for things to check.


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## Tx Jim (Jun 30, 2014)

Does back of belt when in crankshaft pulley extend out past or at least even with edge of pulley? Is bottom of V of pulley shiny?


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## Smallfarmky (May 31, 2017)

New compressor came with clutch/pulley.


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## broadriverhay (Jun 13, 2014)

Look at all the pulleys associated. Probably a worn pulley somewhere or the improper belt. Had an issue at work one time where a belt was replaced with the wrong belt and continued to be replaced with the wrong belt for years. The belt kept rolling in the pulley . Did some investigating and found the proper belt, no more issues.


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## bool (Mar 14, 2016)

Are you using a raw edge belt? That's one where you can see the cords on the driving edge of the belt. They are designed for that application because the raw edge helps grip.

Roger


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## pettibone (Jul 18, 2015)

I think what Jim was saying was if the belt is too narrow it will bottom out in the pulley instead of gripping on sides of pulley, could try a wider belt. Seems like that would be the cheapest part to throw money at.


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## Tx Jim (Jun 30, 2014)

pettibone said:


> I think what Jim was saying was if the belt is too narrow it will bottom out in the pulley instead of gripping on sides of pulley, could try a wider belt. Seems like that would be the cheapest part to throw money at.


That's correct. If pulley has enough wear so factory belt bottoms out in pulley then the V belt looses it's grip.


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## mlappin (Jun 25, 2009)

Tx Jim said:


> That's correct. If pulley has enough wear so factory belt bottoms out in pulley then the V belt looses it's grip.


Look real close at the pulley, fought the power steering on our forklift for years. New pulley on the pump ended the issues.


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## broadriverhay (Jun 13, 2014)

I used to repair small equipment. The dirty environment that mowers run in causes a lot of pulley wear. I used to change quite a few engine and deck pulleys because of wear.


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## hosspuller (Aug 27, 2009)

Since the tractor was built in Italy... likely a metric pulley.. Are you using US belts?

*Metric* *v* *belts* are similar to classic *v* *belts*, except they carry British standard specifications and a different *angle*. *Metric* *v* *belts* are supplied in 10mm, 13mm, 17mm and 22mm widths.

The mis-matched angle prevents full horsepower rating to be transmitted.


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## IH 1586 (Oct 16, 2014)

Smallfarmky said:


> New compressor came with clutch/pulley.


Find the issue?


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## IH 1586 (Oct 16, 2014)

Hopefully op responds. Have not looked into my issue yet.

On my tractor if the pulleys not worn should I attempt the next widest belt?

When replaced them I used oem parts and numbers had changed. Maybe that was not all that was different.


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## Tx Jim (Jun 30, 2014)

Smallfarmky said:


> New compressor came with clutch/pulley.


For AC belt to turn also requires a crankshaft drive pulley that could be worn.


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## IH 1586 (Oct 16, 2014)

https://www.grainger.com/product/DAYCO-Cogged-Automotive-V-Belt-4GKY8?searchBar=true&searchQuery=4GKY8

Replaced the NH belt with this one. Went from metric to standard. Definitely fits the pulleys better. Preliminary results is no squeal, will see after couple hundred hours. I don't think the NH belt lasted that long.

I think when NH changed their part numbers did not make sure item fit all applications, which I'm sure is next to impossible. Have come across that at JD as well.


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## Bruce Hopf (Jun 29, 2016)

I had the same thing happen, with my Alternator. Turned out, that the Belt was Bottoming Out, put a different Pulley on the Alternator, problem Solved. Maybe try a Wider Belt, as it sounds like your Belt, is Bottoming Out, some place, possibly the Pulley, on the Fan, is allowing the Belt, to Bottom Out.


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## IH 1586 (Oct 16, 2014)

Came back across this. Belt never did quite squealing. End result was bad compressor and was replaced spring of this year. Been working good all hay season.


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## ACDII (Oct 1, 2021)

Ran into this during my years turning a wrench. Replace the belt, all was good, they drove off, came back after driving for an hour and it was squealing like a pig. New belt, roughed up the pulleys with 80 grit, all was good for a few days until the belt polished the pulleys, so when it came back the third time I took a good hard close look at the pulleys and found the pulley on the water pump had developed a small crack one third the way around at the bottom of the groove. When cold it was tight, no squeal, but when warmed up the crack would expand and cause the belt to bottom and squeal. Never know what can cause it, but that was an interesting one I found.


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