Lawn Tractor Mower double sheave pulleys

[Duner Wi]

This happens to be an MTD built 834 series about 1995 build year,
Drive belt goes from engine to left side of deck. Mower blade belt is manually tensioned by lever. Belt is kept tight by idler with spring.
My belt seems to slip more than it should especially in grass that is a little tall. Trying to figure out if pulleys wear or belt or both.
Grandson has MTD , one series newer but with same belt, pulley arrangement and it slips about like mine. I know his has Genuine MTD belts on his. Just wondering if anyone has run into the belt slipping problem and what was the fix? Thanks.

 

[J Hamilton]

This happens to be an MTD built 834 series about 1995 build year,
Drive belt goes from engine to left side of deck. Mower blade belt is manually tensioned by lever. Belt is kept tight by idler with spring.
My belt seems to slip more than it should especially in grass that is a little tall. Trying to figure out if pulleys wear or belt or both.
Grandson has MTD , one series newer but with same belt, pulley arrangement and it slips about like mine. I know his has Genuine MTD belts on his. Just wondering if anyone has run into the belt slipping problem and what was the fix? Thanks.

Belts will stretch and wear, which is most likely your problem. Mostly the edges of the belt will wear and it will sit deeper in the pulley groove, thus causing slippage. Use of non- OEM quality belts will cause similar issues due to not being the correct width to fit the pulley correctly. Pulleys will wear too, but after many many hours of use.

 

[DoubleO7]

This happens to be an MTD built 834 series about 1995 build year,
Drive belt goes from engine to left side of deck. Mower blade belt is manually tensioned by lever. Belt is kept tight by idler with spring.
My belt seems to slip more than it should especially in grass that is a little tall. Trying to figure out if pulleys wear or belt or both.
Grandson has MTD , one series newer but with same belt, pulley arrangement and it slips about like mine. I know his has Genuine MTD belts on his. Just wondering if anyone has run into the belt slipping problem and what was the fix? Thanks.

look at the root diameter of the pulleys, are they polished like the V sides?
If yes, the belt may be worn enough that the inner diameter of the belt is bottoming out on the pulley root diameter.
Which is not letting the V shape of the belt and pulley work as good together due to less traction.
MTD is not famous for robust construction. After nearly thirty years the pulleys may be worn enough that the stamped sheet metal pulley sides maybe apart due to the metal being worn away and getting too thin.

 

[T.R.K.]

Look at the profile of the pulley groove. Is it a V with straight sides or is there a pronounced curve or a shallow dip or the wave? If the v sides have much of a curve or a groove or dip in them at all, the pulley is worn out. Be sure to check both or all of the pulleys. If only one is worn that is where it will slip.

 

[Duner Wi]

Thanks everyone for the ideas. I might paint both belts to see if I can determine any difference in wear.