Prevent Riding-Mower deck v-belt from slipping in tall or wet grass

Question

My Yardman MTD riding mower has a deck with a belt that's engaged only when I want to start cutting grass. The deck belt loops around a number of pulleys, and sometimes slips when I go too quickly in long grass, or at a regular speed through thick grass. When the belt slips, the blades slow down so that the grass isn't cut well, and the friction causes the belt to deteriorate faster. I started wondering if there was a way to prevent this, other than mowing really slowly.

I should clarify that this is an old beat up mower, and the previous owner already made modifications - with various results. For instance, I can't raise or lower the deck height. So how do you keep a riding mower belt from slipping?

Answer 1

Rosin/Pine sap.

I remembered that baseball players sometimes use rosin in their gloves to keep the baseball from slipping out.

"Rosin, also known as colophony, is the sap or sticky substance that comes from pine and spruce trees.
 Its stickiness lends itself to being used in a wide range of products."

source

So I went over to a grove of pine trees, pulled off a clump of sap on the side, and rubbed it on the pulleys and belt of my mower. Then, to clean my hands off I had to use another trick: I rubbed my hands in vegetable oil until the sap mixed with the oil. Then I washed it all off with normal hand-soap. The belt hasn't slipped yet!! And now I can mow through taller grass at full-speed. It works great.

---

I should clarify that this is an old beat up mower, and the previous owner already made modifications - with various results. For instance, I can't raise or lower the deck height. In general it's best not to deviate from the operation manual on a newer mower. When reviving old equipment however, sometimes you need to be resourceful. Otherwise it's time to replace major components or buy something brand new. I could get a faster stronger mower, but this hack has saved me time and money. Also, sometimes the grass is just thicker in certain spots on my lawn where water drains more frequently.

Answer 2

Two things to consider: first, that older mowers usually have automobile-type fan belts in them which slip and wear out quickly. You need to try drive belts designed specifically for garden tractors and not cars. They last much longer and grip better.

Second, you can buy aerosol belt dressing at auto supply stores which, when sprayed on the belt, increases the coefficient of friction between the belt and the pulley sheave and eliminates slippage.