Belt Drive slipping?

L

LewP

Forum Newbie
MTD mows good most of the time but occasionally the mower will not be able to pull itself uphill even small inclines especially when the grass is wet. I can drop mower in lower gear and it helps. I can also "pop" the "clutch" (not really) and it seems to do better.

All belts are working but the mower is 7 years old and I have never changed either drive belt. Could this be it? How do you know? Could it be a tension spring on an idler pulley?
 
I would change both drive belts.

When the belts get bad it will pull best in low gear and highest gear. Just had to put two on mine

(( racing is the only sport that you need two balls ))
 
In general, belts have to be in pretty poor condition to prevent lawn tractor movement . But after 7 years ( operating hours unknown ) that is one possibility . I have no idea how wet grass plays a role in this equation .

I suspect we're looking at a vari-drive system and there are 3 items that could be the culprit besides belts . 1 ) Self regulating rear belt idler tension not pivoting . 2 ) Operator regulated front belt idler tension not pivoting with speed selector changes . 3 ) Variable speed sheave not responding to item # 2 .
 
SandburRanch said:
In general, belts have to be in pretty poor condition to prevent lawn tractor movement . But after 7 years ( operating hours unknown ) that is one possibility . I have no idea how wet grass plays a role in this equation .

I suspect we're looking at a vari-drive system and there are 3 items that could be the culprit besides belts . 1 ) Self regulating rear belt idler tension not pivoting . 2 ) Operator regulated front belt idler tension not pivoting with speed selector changes . 3 ) Variable speed sheave not responding to item # 2 .
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I agree that the belt has to be in pretty poor condition to prevent movement. It looks like he has a MTD mower which is belt driven, does MTD make a vari-drive or what is a vari-drive?
 
:smile: Ditto, to what SandburRanch stated. When you pop the clutch you are shocking the variable speed sheave. I just worked on one this summer, Vari-speed sheave froze up, one heck of a time getting it off and unfroze. Also replaced the belts. When replacing belts on MTD products, I have found to use belts from MTD. I have tried after market belts and they just flat will not work. Mtd belts have a different pitch along with several others JD and Simple city for a couple.
 
Buckshot 1 said:
:smile: Ditto, to what SandburRanch stated. When you pop the clutch you are shocking the variable speed sheave. I just worked on one this summer, Vari-speed sheave froze up, one heck of a time getting it off and unfroze. Also replaced the belts. When replacing belts on MTD products, I have found to use belts from MTD. I have tried after market belts and they just flat will not work. Mtd belts have a different pitch along with several others JD and Simple city for a couple.
Click to expand...
The one I repaired for a neighbor, and hopefully the last, the center sheave was froze so I thawed it with a torch . :laughing: I made a wooden wedge about the same angle as the V - belt but smaller and after heating the outer edge of the moveable sheave to prevent shaft heating, drove the wedge in . By continuing to rotate to different areas with the wedge and on opposite sides I finally saw a few thousandths movement . :thumbsup: Things got better from there .

Ditto on the belts . You won't like the price one bit but that's about all the choice unless an industrial supply might be able and willing to duplicate OEM belts .

Operation : once travel commences do not use the clutch to change speeds . This system was designed to simply move the speed control lever . Clutch only when stopping and or reversing direction . That's all in the manual but where did the manual go . That's probably the most misplaced / lost piece of paper on earth .
 
:smile: SandburRanch, yes definitely sticker shock on MTD's belt prices. There have been a several of aftermarket companies that try to duplicate the MTD belts, but when you compare them to each other, the pitch on the AM's are not correct. Therefore they ride lower in the sheaves. causing all kind of problems.
 
Just got a deck belt list on MTD site for $55 I get them at ace hardware for $33. I try never to buy belts at tractor supply they want $62 Walmart also sells MTD belts. They really are worth the price they last long and you can stall the engine before a deck belt will slip.

(( racing is the only sport that you need two balls ))
 
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