36in RD deck eating up belts

[matt monte 233]

Happy i can weld!  After carefully removing pulley, i hit it with a wire wheel. I determined it could take a weld so i carefully stitched up rust holes, sanded smooth, and painted. Unfortunately like everyday, i just ran outta time, lol. Tomorrow ill head up to TSC for one of there ghetto blue belts. The amount of dust those belts make is ridiculous. Not gonna get a WH belt until I see problem is resolved. I spun by hand from the blade. Didnt see any warpage. double checked idler pulley, other spindles spun, slide pivots as it should.  Glad i made this blog in an effort to show an alternative to just buying another pulley. Guess we will see what brings next week when i mow again.

[Ed Kennell 47,805]

Nice work rebuilding the pulley, but I would try to find a better one for back up.

[matt monte 233]

decided to run it without the belt guard covers. what is going on here, clearly something is not right. do the guards act as a belt guide when in place? if u look closely it appears that there is so much play while running  it doesn't look as if that closest spindle is operating correctly 

[matt monte 233]

without having an engineering degree here, im gonna go out on a limb and say either the center pulley i welded is bent or the spindle itself is

[Brockport Bill 2,510]

18 hours ago, matt monte said:

 

[Brockport Bill 2,510]

i have seen a hub " puller tool" never a pulley "puller tool" - where do you buy that?????????????

[Ed Kennell 47,805]

Looks like the belt tensioner is maxed out and not tensioning the belt.  Get a shorter belt or move the idler pulley to the other hole in the slide bar.

 

The belt guards do nothing but collect dirt.    I throw all mine away.    Oh, and I don't wear flip flops.

Edited June 28, 2025 by Ed Kennell

[Brockport Bill 2,510]

the parts diagram online  shows the proper hole for the idler pulley -- closest to spring end - -the manual i recall shows the proper adjustment placement for torsion bolts and bushings to slide properly

wh 36 rd parts diagram.html

[Brockport Bill 2,510]

14 minutes ago, Ed Kennell said:

Looks like the belt tensioner is maxed out and not tensioning the belt.  Get a shorter belt or move the idler pulley to the other hole in the slide bar.

 

The belt guards do nothing but collect dirt.    I throw all mine away.    Oh, and I don't wear flip flops.

i dont trust my feet - - i keep my belt guards installed -- but i use leaf blower after every mow to clean off tractor and deck including blowing out under the covers

[matt monte 233]

Thanks guys, ill pull deck off for the 10th time, lol oh man...  I didnt buy it, I cobbled together a puller to fit my needs. base is part of a GM steering column puller i believe. I ran a 1/4 in. tap down those 2 holes in pulley, took off grease fitting, and a little "heat' . Amazing i can figure out how to remove pulley without destroying it yet am completely baffled by a floppy belt.  Ill print out diagram and get back at it tomorrow morning 

[matt monte 233]

good to know covers do nothing for belt alignment, would of gone down that rabbit hole for hours!

[Lee1977 7,809]

That pulley you fixed might be causing the belt to do that.  If is tighter where you welded it . As Ed said the Idler pulley might not be in the right hole on the slide bar. 

If you want it right might have to get another pulley.  I have completely worn out a set of those stamped steel pulleys to a point where they would not cut high or heavy thick grass.

[The real milo 2]

On 6/26/2025 at 5:50 PM, matt monte said:

Was looking for some insights from the experts as im clearly over looking something. Deck is shredding belts. Had those true blue belts to start with other than getting blue dust everywhere, deck worked as it should April/May/June. About 2 weeks ago, outta nowhere, it chewed up deck belt. I ordered the correct WH belts from A-Z, they weren't cheap. 1st mow today ate up new deck belt. Prior to ordering, I did the obvious, checked play in the 3 spindles and idler pulley. No major drag. Idler pulley spring seems to pivot correctly. What am i missing here? I have other WHs, b80,312 and a 308 but I built this C-100 over the last few years and enjoy using this one for weekly mow, runs great. Can i be running at to high of a RPM while cutting? Lawn is deep plush healthy grass. While not wet its definitely thick, clumpy almost, however that shouldn't be an issue. my 312 with a 42 SD cuts it without issue.  

Mower deck 9536MR01-41043-9197

belts  8411 & 102607

 

Thanks in advance for help!

 

First off, it is definitely not high RPMs killing the belt, because that Kohler K241 on your C-100 is meant to run wide open at 3600 RPM to keep the blades cutting cleanly instead of lugging in thick grass. When a 36-inch rear-discharge deck (that 05-36MR01 / 95-36MR01 setup) runs fine for three months on a Blue Kevlar belt and then suddenly shreds two belts back-to-back while the spindles feel smooth by hand, check three hidden spots:
A nick or rust pit inside a pulley V-groove: Run a cotton ball or shop rag around the inside V-walls of all three spindle pulleys and the flat face of the idler. If a tiny rock got pinched between the belt and pulley two weeks ago, it leaves a razor-sharp burr in the stamped steel sheave that acts like a cheese grater under load, explaining all that blue dust you saw earlier.
Worn idler slide bar or trunnion bushing: On those Wheel Horse decks, the flat idler pulley mounts on a flat steel slide bar that moves back and forth in slots. When you spin it by hand with the belt off it feels great, but once the spring pulls 40 lbs of tension on it in thick grass, a worn bushing lets the idler tilt 5 degrees downward and forces the edge of the belt to ride up the pulley flange until it rips the cords out.
Cracked spindle mounting surface: Grab the top of each spindle pulley and pry sideways hard. Sometimes a hairline crack forms in the deck shell around the spindle bolts, so the spindle sits straight at rest but ***** sideways the second you drop the deck into thick turf.
I went through this exact nightmare two summers ago on an old tractor I restored with my old man in Ohio. We burned through $90 worth of expensive OEM belts in a single weekend and swore the deck was haunted, until I finally flipped it upside down on sawhorses and noticed a tiny weld bead had popped loose on the tensioner bracket, making the pulley lean just enough under load to saw the belt in half. Double-check the pulley alignment points in this riding lawn mower deck belt change guide before you sacrifice another expensive belt to the lawn gods: https://udcparts.com/blogs/news/riding-lawn-mower-deck-belt-change-how-to-replace-it