Mowing Mower Belt

marrt · May 27, 2003

Over the weekend, I decided to take one on the 60” mower spindles off to see if I could determine where all the grease goes. Before I mow my three acres, I always grease the spindles and it takes 10-12 “pumps” of the grease gun. That’s a lot of grease. I couldn’t determine where the grease goes but I did discover another problem. My belt is about to break in 5 or more places. In a couple places, the belt is torn all the way through except for the last 30 percent or so. I thought I would just go online and order a heavy duty Kevlar belt. However, the PT belt is ½” and 122” long. It is made by Jason Industries and has an “A 120” stamped on it. The problem is…I can’t find ANY A 120 belts, Kevlar or not. Anyone have a source on these other than PT?

My thinking is that the belt should be 5/8” (which are readily available) for this application. Unfortunately, the pulleys are ½”. Would a 5/8" belt work? I would consider changing the pulleys but that is a bigger proposition as I have no idea who makes the PT spindle or if I could get an aftermarket replacement. Any ideas?

Bob999 · May 27, 2003

I have an old catalog but in it Grainger carries your belt size--although not in Kevlar.

Sedgewood · May 27, 2003

MSC ( www.mscdirect.com ) offers two:

A Goodyear at $29.99

( Click here )

A Made in USA at $18.93

( click here )

I've also had good luck at NAPA

Sedgewood

Charlie_Iliff · May 27, 2003

Marrt:
My belt on the 72" also developed cracks on the v pulley side, I assume because of the idler pulley against the back. After the cracks developed, I mowed a few more hours without failure. Apparently much of the cord strength is in the back third of the belt.
I replaced mine with a NAPA belt.

Anonymous Poster · May 28, 2003

hey mart - just curious, how many hours did you get out of the belt?

marrt · May 28, 2003

Guys,

Thanks a lot for the suggestions. I ordered a Dayco cog belt from Granger. The cog feature should help relieve some of the tension on the inside of the belt as it goes around the idler pulley. For those interested, Dayco has a very detailed build selection guide (in pdf form) on their site with lots of formulas to calculate the appropriate belt based on HP, torque, pulley size, etc…. The bottom line is that PT definitely uses the wrong size belt given a reasonable estimate for the HP requirements of the mower. That said, belts aren’t all that expensive so I guess it doesn’t matter in the long run. I know that some of the larger PT tractors have a commercial mower option. From the size of the belt enclosure, I’m guessing these mowers have double pulleys.

Ed, my tractor currently has 106 hours. The belt hasn’t actually broken yet and I think Charlie is right about most of the chords, and therefore strength, being on the outside of the belt. Therefore, the belt may last a while longer. I mowed two more hours on Monday anyway. I don’t guess it will harm anything if it breaks so I may wait until its convenient to replace it. Just want to make sure I have one on hand when the time comes.

Also, did you ever get around to fabricating that attachment adapter to use 425 attachments with your 1845? I’m thinking about trying to find a used 1430 or 1845 and would be interested in keeping some of my 425 attachments to use with the larger tractor.

Sedgewood · May 28, 2003

marrt: I know that some of the larger PT tractors have a commercial mower option. From the size of the belt enclosure, I?m guessing these mowers have double pulleys.


Ha! Yeah, right - they went all the way up to a single "B" section belt on my 6 ft roughcut mower. It broke in less than 50 hours - partly I think because I tightened it a bit thinking slippage might account for the poor cut. It didn't. And so far so good on the second belt (a NAPA).

Sedgewood

Anonymous Poster · May 28, 2003

Hmmm - not many hours - I was just curious because
I inspected the belt on the 425 before i delivered it to my brother in law - it had about 3/4 of a summer use on it and it looked good - I also wonder where all that grease goes - it seemed like it would take half the tube

I did build the converter plate - I have to get some photos and post them - I have done a number of things - getting behind posting what I have done - I have been really busy

I works good - it would be a pain if you used the attachment all the time - it would be better to just change the plate - I use it for attachments you only use a couple times per year
(and I share with my brother in law)

Bob999 · May 28, 2003

I know that some of the larger PT tractors have a commercial mower option. From the size of the belt enclosure, I’m guessing these mowers have double pulleys.


I have the 72" finish mower and it has a single "B" section belt!

marrt · May 29, 2003

I did build the converter plate - I have to get some photos and post them - I have done a number of things - getting behind posting what I have done - I have been really busy


I hear ya. I have made a couple mods as well and bought a tow behind mower. However, I can't find time to get some pics posted. I am interested in your design though. I still haven't figured out how to do it. I would also only need that capability for a couple of implements that I would use occasionally.