Welcome to the DoItYourself Forums!

To post questions, help other DIYers and reduce advertising (like the one on your left), join our DIY community. It's free!

Craftsman tractor belt problems


scammy's Avatar
Member

Join Date: Aug 2008
Posts: 9

08-02-08, 10:38 PM   #1  
Craftsman tractor belt problems

Hello,

I have a Craftsman Model Number 917.256711 (18HP Kohler 46" Deck).

I recently had the electric clutch (PN: 137140) actually fall off while I was mowing the grass and broke the drive belt along with it. It looked like the bolt came loose and fell off. I put it back on but the clutch did not engage. I then replaced the clutch (PN: 137140) with one that Sears said was equivalent. I think it crossed over to a Warner Electric PN: 5215-51. I also purchased a drive belt (PN: 148763). The belt was actually mfg by PIX which said it was 5/8" X 85-3/8".

I put everything together and the clutch engaged fine and I thought everything was good. I mowed the lawn about 2 times and the drive belt broke.

I replaced the belt again and after mowing the lawn one time, I can see the belt is already starting to wear excessively. I thought this was probably due to one of the pulleys or bearings going bad. I check all pulleys and mandrel bearings. Everything is fine. I also checked the pulley alignment and everything is fine. I verified the deck is properly leveled and aligned.

I know this belt is going to break very soon. I just can't figure out what is wrong. The original belt/electric clutch lasted over 8 years with no abnormal wear.

One thing I did notice was that the electric clutch that I purchased (Warner Electric 5215-51) said that it uses a 1/2" belt specified by the OEM. THe belt that sears specifies is 5/8". It seems like this could be the culprit. Should I try a 1/2" belt?

Any help here would be greatly appreciated. Sorry for the long post - I just wanted to give all the details.

Thanks in advance for your help.

 
Sponsored Links
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,567
GA

08-02-08, 11:49 PM   #2  
If the clutch takes a 1/2" belt, and you're using a 5/8", then there's the problem. The thing is, if you use a 1/2" belt, it may not seat in the rest of the pulleys that are made for a 5/8" belt. Sounds like you've got the wrong clutch for the mower, even if the part#s say it's right.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
scammy's Avatar
Member

Join Date: Aug 2008
Posts: 9

08-03-08, 08:33 AM   #3  
Cheese,

Thanks for the reply! I thought the same thing about the belt width.

There are many websites that show Warner Electric 5215-51 as an equivelent to Craftsman 137140. Most websites show the spec as a 1/2" belt but some show 5/8".

I guess I need to find the real story on this.

 
30yearTech's Avatar
Member

Join Date: Oct 2006
Posts: 1,176
TX

08-03-08, 04:00 PM   #4  
Many of my catalogs show that this clutch can be used with either a 1/2" or 5/8" width belt.

Does the wear on the belt appear to be on the inside or outside of the belt?

Is the belt maybe rubbing on one of the belt guides?

 
scammy's Avatar
Member

Join Date: Aug 2008
Posts: 9

08-03-08, 05:09 PM   #5  
The belt is wearing on the inside part of the "V" on only the bottom edge.

All the pulleys are square except for the clutch pulley since the belt goes a little downward towards the deck. I'm guessing this is where the wear is coming from. When the deck is low, it looks like the clutch pulley is eating into the belt. I think the wear is a little less when I mow with the deck in the highest position.

 
30yearTech's Avatar
Member

Join Date: Oct 2006
Posts: 1,176
TX

08-03-08, 05:35 PM   #6  
Was there any spacers between the clutch and drive pulley that may have fallen off when the clutch came off??

Is your clutch installed with the pulley side down? Some clutches can be flipped and installed either way.

 
scammy's Avatar
Member

Join Date: Aug 2008
Posts: 9

08-03-08, 06:32 PM   #7  
Well, the parts book does not show any spacers on the clutch. When it fell out, the only thing I found was the clutch, the rest of the hardware (bolt, washer, etc.) must have fell out.

My clutch is installed with the pulley side down.

 
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,567
GA

08-04-08, 12:24 AM   #8  
Sounds like the belt may be installed over a belt keeper/guide. Check every pulley and all along the path of the belt to be sure it's touching nothing but the pulleys.

After your description of the wear and 30Yeartechs' info about the clutch, I don't think the belt size is the issue. In fact, I don't think I even recall seeing any electric pto clutches that wouldn't accept a 5/8" belt.

It's normal for the belt to drop some as it leaves the pto when the deck is down, since obviously the deck level varies and the belt must accomodate it. It shouldn't be so much as to let it ride the edges of a pulley though.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!


Last edited by cheese; 08-05-08 at 12:42 AM. Reason: typo
 
scammy's Avatar
Member

Join Date: Aug 2008
Posts: 9

08-04-08, 02:24 PM   #9  
Posted By: cheese Sounds like the belt may be installed over a belt keeper/guide. heck every pulley and all along the path of the belt to be sure it's touching nothing but the pulleys.

After your description of the wear and 30Yeartechs' info about the clutch, I don't think the belt size is the issue. In fact, I don't think I even recall seeing any electric pto clutches that wouldn't accept a 5/8" belt.

It's normal for the belt to drop some as it leaves the pto when the deck is down, since obviously the deck level varies and the belt must accomodate it. It shouldn't be so much as to let it ride the edges of a pulley though.
No, it is not installed over any belt keeper or guide. It is squarely on every pulley on the deck. As far as the clutch pulley, the description of the clutch says it is for a 1/2" belt. That is the only reason I bring this up.

Thanks,

 
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,567
GA

08-05-08, 12:46 AM   #10  
Does the clutch move up and down on the shaft even with the bolt tight? After re-reading this thread, I just got the fact that it's wearing on the bottom side of the V. My first impression was it was wearing on the narrow flat part of the V. If it's on the bottom surface of the angled side of the V, then I'd think it is riding hard on one sheave of a pulley. The one I'd look at most is the PTO pulley. Is this PTO clutch the same as the old one? Did the old one have a dropped pulley where maybe this one does not?


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
scammy's Avatar
Member

Join Date: Aug 2008
Posts: 9

08-05-08, 02:18 PM   #11  
Posted By: cheese Does the clutch move up and down on the shaft even with the bolt tight? After re-reading this thread, I just got the fact that it's wearing on the bottom side of the V. My first impression was it was wearing on the narrow flat part of the V. If it's on the bottom surface of the angled side of the V, then I'd think it is riding hard on one sheave of a pulley. The one I'd look at most is the PTO pulley. Is this PTO clutch the same as the old one? Did the old one have a dropped pulley where maybe this one does not?
Cheese,

THanks for the insight - you are correct. When I said "bottom part of the v", I did mean the bottom surface of the angled side.

Unfortunately, I don't have the old clutch anymore but the pulley arrangement looks the same. I guess, it is possible that I may have some lateral movement (up & down) on the clutch. I'll check and report back.

 
scammy's Avatar
Member

Join Date: Aug 2008
Posts: 9

08-05-08, 08:48 PM   #12  
Cheese,

I verified that the clutch pulley has no up & down or side-to-side movement. When you turn the pulley, there is a little bit of motion on the entire clutch assembly until the anti-rotation rod hits but this is expected.

I'm totally stumped by this. Other than trying a 1/2" belt, I can't find the cause of the belt rub.

 
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,567
GA

08-06-08, 12:33 AM   #13  
I wish you had the old clutch so you could see if the pulley went down father than the one you corrently are using. Many of them have a pulley that drops down a couple inches to relieve the downward bend that the belt must do to reach the pulleys on the deck. Other PTO clutches have the pulley right directly under the clutch, but when that clutch is used, it is usually in combination with a deck that has a high pulley up on a shaft that transfers the motion to the secondary belt on a lower pulley on the same shaft.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
scammy's Avatar
Member

Join Date: Aug 2008
Posts: 9

08-06-08, 08:38 PM   #14  
Cheese,

I mowed the grass again with the tractor with the same 5/8" belt and noticed that the belt is still wearing and can tell it will break the next time I mow.

One observation - The idler pulley (PN 146763 - Item 127 on the parts manual) is connected via a spring and bracket to the deck. I noticed that this pulley vibrates quite a bit when running at full throttle with the deck engaged. Is this normal?

I removed the deck and drive belt so the idler pulley was free. It rotated freely (when turned by hand) with no hesitation and I could not see any wobble either. To me, this indicates that the bearing in that pulley is fine. The whole assembly with the spring pivots fine and there seems to be adequate tension in the spring. This pulley sits a little higher than the other pulleys. It just seemed really odd that it was vibrating more than all of the other pulleys. Other than this, there is no noticeable vibration on the deck.

Is it possible that the bearings in the pulley are bad even though there is no wobble and it turns freely by hand? Is it possible that the spring is losing its elasticity and therefore causing the vibration (I doubt this).

Any help would be appreciated.

PS the mandrel pulleys all seem fine with no play and all turn freely.

Thanks,

 
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,567
GA

08-06-08, 11:35 PM   #15  
Excessive vibration or rapid bouncing of the spring tensioner indicates a thin spot in the belt. The thin spot enters a pulley, going deeper into the V of the pulley, so it gets looser and the spring tensioner has to tighten a little, but as the thin spot of the belt exits the pulley, the belt rides back out into the V where it should be which tightens the belt a bit and the tensioner accomodates it. As the belt does this at several RPMs, the tensioner just bounces.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
bontai Joe's Avatar
Member

Join Date: Apr 2004
Posts: 592
PA

08-07-08, 09:46 AM   #16  
Posted By: scammy Cheese,

I mowed the grass again with the tractor with the same 5/8" belt and noticed that the belt is still wearing and can tell it will break the next time I mow.

One observation - The idler pulley (PN 146763 - Item 127 on the parts manual) is connected via a spring and bracket to the deck. I noticed that this pulley vibrates quite a bit when running at full throttle with the deck engaged. Is this normal?

I removed the deck and drive belt so the idler pulley was free. It rotated freely (when turned by hand) with no hesitation and I could not see any wobble either. To me, this indicates that the bearing in that pulley is fine. The whole assembly with the spring pivots fine and there seems to be adequate tension in the spring. This pulley sits a little higher than the other pulleys. It just seemed really odd that it was vibrating more than all of the other pulleys. Other than this, there is no noticeable vibration on the deck.

Is it possible that the bearings in the pulley are bad even though there is no wobble and it turns freely by hand? Is it possible that the spring is losing its elasticity and therefore causing the vibration (I doubt this).

Any help would be appreciated.

PS the mandrel pulleys all seem fine with no play and all turn freely.

Thanks,
Why does the idler sit higher than the other pulleys? They should all be in the same plane (geometrically speaking).

 
scammy's Avatar
Member

Join Date: Aug 2008
Posts: 9

08-24-08, 12:18 PM   #17  
Problem Solved!

I think I solved the problem.

The idler pulley had some rust on it, so I replaced it but I don't think this was the problem.

This time I decided to buy the OEM belt. Before installing the new belt, I compared the old "equivalent" belt and noticed that the OEM (AYP) belt was slightly thinner than the other belt. Also, it was a little shorter as well. When I installed it, the AYP belt was a lot harder to get on because of this but it was tighter.

I mowed the lawn once already and no belt wear at all. It looked brand new with no abnormal wear - FINALLY!!!

Lesson Learned - ALWAYS BUY OEM BELTS EVEN IF THEY ARE A LITTLE MORE EXPENSIVE.

In trying to save a few $$$, I purchased "2" generic belts and countless hours of headache and troubleshooting.

Thanks to all to responded to my posts. This is a really helpful forum.


 
Search this Thread