Why would the belt slip off of my 518-H?

[rprevost 0]

When I try to mow with my 518-H, the mower belt slips off every 2 minutes.  I stop, put it back on, mow a little, and it pops off again.  Can someone explain to me what I need to do to stop this?

 

I thought that I would start with replacing the belt.  However, I cannot find what part number it is.  I have the parts and service manual for that model, but it does not say what the part number is for this belt.  Can I go to Lowe's and pick up a belt that will work?

 

Any help is appreciated!

 

RP

[Hodge71 665]

First thing we would like to know is which belt. Is it the belt going through your mule drive or the deck belt?

[WH nut 553]

Before you change any belt you need to make sure all pulleys and bearings are good or you will have the same problem.

[rprevost 0]

This is the belt that goes from the PTO over the front of the mower to the deck below.   I tightened the belt each time it would come off, but that did not seem to make much of a difference.

[Tankman 3,523]

I use belts from Tractor Supply (a local outlet) or any automotive parts outlet.

The Huskee Kevlar® belts from Tractor Supply have been mowin' away for a year or two. Still look new.

The mule drive belt is .500" x 103".

6378 Gates 1/2"x 103-1/4" 40 degrees

6378 Napa 1/2"x 103-1/4" 40 degrees

Stens 1/2"x 103"

89204 Goodyear 1/2"x 103"

AP100 Dayco 1/2"x 102"

I keep a spare hangin' in the barn but, never need it. If the pulleys are straight 'n level the belt shouldn't be jumpin' off the deck. Are the mule drive pulleys in good condition? Check them too.

FYI. http://www.partstree.com/parts/?lc=Toro+Consumer&mn=e5-48sc01

[tarcoleo 119]

Assuming that all is aligned and all bearings check out, your problem in my experience is

the usage of a wrong belt.  Some years ago I assumed that a 5/8" belt would last

longer than a 1/2" belt.  WRONG! The 5/8" belt in short order came off with the

regularity you describe.  With the 1/2" I have no problem with belt life or the belt

coming off.

[rprevost 0]

Thanks for all the replies.  I want to give an update, and I have another question:

 

I checked the pulleys and they all seemed to function properly.  I ordered a new belt.  When it arrived, I found that it was wider than the one that was on it.  When I put the new belt on, it seemed to solve the problem of the belt slipping off.  However, it started a new problem.  Now when I engage the PTO, it will stay engage for about 30 seconds and then it will pop off.  The lever for engaging the PTO to start the mower deck pops out of engagement.  II assume that it has something to do with the new belt.  Can anyone tell me whether this is something to worry about?  I am thinking now that this will stop once the new belt gets some time on it.  Thanks in advance for any advice.

 

Rob Prevost