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New Drive Belt Burning Hot

#1

L

LarryJohnson

Installed a new oem drive belt today and notice it smelled during initial test drive. Extemely hot to the touch. When replacing I noticed one of the belt guides was worn. This belt is much thicker than old after-market belt. Guides aren't bent. I rotated the worn guide , but still belt gets hot. Normal?


#2

Scrubcadet10

Scrubcadet10

what is the model# of the tractor?


#3

B

bertsmobile1

The belt is wrong or has been routed wrong or one of the idlers has seized
Guides always go to the outside of the belt,


#4

H

hlw49

No not normal.


#5

StarTech

StarTech

Is this an OEM belt or after market? I have seen where an after market supplier will try to use a 1/2 in place of a 7/16 belt. I have this to happpen on a CC I was replacing the drive belt on.

Also we need the equipment numbers and the belt PN used.


#6

L

LarryJohnson

Scrubcadet10 said:
what is the model# of the tractor?
Click to expand...
Murray 465306x8B


#7

L

LarryJohnson

bertsmobile1 said:
The belt is wrong or has been routed wrong or one of the idlers has seized
Guides always go to the outside of the belt,
Click to expand...
The belt is spec. Guides are on the outside. Idlers spin fast enought to whistle while compressed air is blown over them.
Belt S's through the idler. Had to really squeeze the belt between idler pulleys.

Untitled by Larry Johnson, on Flickr


#8

M

MParr

Rotary Brand replacement: https://www.rotarycorp.com/search?q=37x112ma

Stens Replacement: https://www.stens.com/265-848-oem-replacement-belt

Check your routing and pulleys.


#9

R

Rivets

If you can make the pulleys whistle when you blow air on them, I would say the bearings are worn. A good bearing should not make noise. That and a slightly short belt will heat up quickly.


#10

StarTech

StarTech

Double check the routing at the steering wheel shaft.
1629037350109.png
1629037463106.png


#11

L

LarryJohnson

Rivets said:
If you can make the pulleys whistle when you blow air on them, I would say the bearings are worn. A good bearing should not make noise. That and a slightly short belt will heat up quickly.
Click to expand...
The pulleys began whisling because they were spinning about 5000rpm. bearings are good.


#12

R

Rivets

5000 RPMs? Ok, ain’t worth any more of my help, your know more than me. Good Luck.


#13

M

MParr

LarryJohnson said:
The belt is spec. Guides are on the outside. Idlers spin fast enought to whistle while compressed air is blown over them.
Belt S's through the idler. Had to really squeeze the belt between idler pulleys.

Untitled by Larry Johnson, on Flickr
Click to expand...
That’s the correct belt. Something else is wrong.


#14

L

LarryJohnson

StarTech said:
Double check the routing at the steering wheel shaft.
View attachment 57934
View attachment 57935
Click to expand...

Double-checked the alignment at the steering. Top of belt rubs against the bottom of L-guide. Would that cause it?
Untitled by Larry Johnson, on Flickr


#15

M

MParr

The guide should be at a 90 degree angle. Something doesn’t look right with that idler. It looks like the belt is riding too high. Are all of your pulleys bolted down tight? Something is out of whack.


#16

L

LarryJohnson

MParr said:
The guide should be at a 90 degree angle. Something doesn’t look right with that idler. It looks like the belt is riding too high. Are all of your pulleys bolted down tight? Something is out of whack.
Click to expand...
What do you mean, the guide should be at a 90 degree angle? 90 degrees from what?
Seems like it is as shown in manual, no?

Attachments





#17

StarTech

StarTech

The idler looks like it is the wrong one.

Images of the 1001187MA Top left - Bottom Right
1629056533859.png1629056653977.png


#18

M

MParr

LarryJohnson said:
What do you mean, the guide should be at a 90 degree angle? 90 degrees from what?
Seems like it is as shown in manual, no?
Click to expand...
90 degrees to the deck. In other words, the inside angle should be the same height off the deck as the other end. A perfect L is 90 degrees as well. I agree with @StarTech. That looks like the wrong idler.


#19

H

hlw49

Is that the one where steering post has to be remove and the steering post goes inside the belt? I believe it is.


#20

L

LarryJohnson

StarTech said:
The idler looks like it is the wrong one.

Images of the 1001187MA Top left - Bottom Right
View attachment 57937View attachment 57939
Click to expand...
Good call. The top of the idler is worn. I never imagined it was worn so much.
With a new idler, woudn't the belt still rub against the bottom of the L-bar.


#21

M

MParr

LarryJohnson said:
Good call. The top of the idler is worn. I never imagined it was worn so much.
With a new idler, woudn't the belt still rub against the bottom of the L-bar.
Click to expand...
Just pry the L-bar up a little. Don’t force it. Nice and easy. Or, grab the bar between the deck and the 90 degree bend, with a pair if vice grips, and bend towards the centerline of the mower. You want it square with the deck.


#22

L

LarryJohnson

MParr said:
Just pry the L-bar up a little. Don’t force it. Nice and easy. Or, grab the bar between the deck and the 90 degree bend, with a pair if vice grips, and bend towards the centerline of the mower. You want it square with the deck.
Click to expand...

Removed the idler and bent up the L-guide so belt doesn't rub. Test drove, but drive belt getting hot, smoking.
I think it's an issue with the double idlers. I had to really force the belt between the two pulleys when installing. Or maybe the belt is just too thick/wide like someone said earlier.


#23

M

MParr

Remove the belt and put your hands on every pulley, idler and turn the blades by hand. Something is in a bind. If any pulleys have been replaced, an incorrect pulley could have been installed. This inspection needs to be done by hand and not by blowing compressed air on them.
One more thing, jack your mower up and make sure it’s in neutral. Spin the wheels by hand and turn the transaxle pulley by hand. Is your transaxle binding up?


#24

B

bertsmobile1

Block off the filling neck and if you have fitted an open cell battery remove it.
Drop the deck then stand the vertical and take a couple of good clear photos of the belt run .
We need to see the entire belt run in one photo ( like the diagram Star posted ) so we can see for ourselves what is where.
Otherwise his post is just going to go round & round in circles.
Also did you remove the top ( rear ) belt when you replaced the front ( lower ) belt ?
I have seen one case where a customer had them on the wrong sides of the variator.
God only jnows how he did that I have enough problems getting them on the right side.
PLease do not even think of shoving your phone under the mower on the ground because that will not give us the information we need.
Also have a good look at the belt itself.
Where it is burning it will leave tell tale marks and from the damage we ran determine the type of the cause .


#25

M

MParr

I haven’t seen any mention of the operators manual. I have no idea if the OP even has a manual. There are clear instructions on how to check and adjust the motion drive and belt. The manual is available online.


#26

L

LarryJohnson

MParr said:
I haven’t seen any mention of the operators manual. I have no idea if the OP even has a manual. There are clear instructions on how to check and adjust the motion drive and belt. The manual is available online.
Click to expand...

Thanks for all the suggestions. I do have a manual. I referred to the manual 5 yrs ago when I replaced both drive belts and last week when I replaced the front belt.
I work for aliving, so might be the weekend before I can can try any suggestions.


#27

B

bertsmobile1

LarryJohnson said:
Thanks for all the suggestions. I do have a manual. I referred to the manual 5 yrs ago when I replaced both drive belts and last week when I replaced the front belt.
I work for aliving, so might be the weekend before I can can try any suggestions.
Click to expand...
Lucky you.
I am top poster at present because we are in covid lockdown right now.
The government failed to manage airport quarrintine properly and allowed Covid to escape , then bungled the lockdown preffering to blame the ethnic migrants .
So now we are in the 7th week of a 2 week lockdown & they are pretending to be trying to get it under control while all the time relying on increased vaccinations to initate herd immunity mcuh the same as the US & UK
So we had it licked but never underestimat the ability of a government to stuff things up
Looks like it will be christmass before I am allowed to go back to work.
And that is assuming another variant does not pop up and the immunity to the delta strain actually lasts for that long
Tis really amazing to see how a single infected person can blow out to over 3000 cases in 7 weeks , kill 14 people and have 70% of the population locked up at home .
So I for one have all the time in the world to wait for you to get back under your mower.


#28

StarTech

StarTech

And just think we here are now up to 200,000 cases a day again. Just because everybody went hog wild here too. Mostly the non vacinated is driving this.

People the masks are so restrictive they can't breathe through them have never had to wear the organic vapor versions. Now they are restrictive but can still save your life.


#29

B

bertsmobile1

I know the Aust number look small but to equate them to the USA's larger population multiply by 10.
However the big difference is we had eliminated covid totally from the general population .
All of the current cases originated from a known single person ( DHL flight crew )
Thus we have just provided the world with a real time field experiment on exactly how infectious Covid Delta really is.
The USA had hundreds of cases in the country before they knew about it so no one really knew how many people a single person could infect & how fast it could spread .


#30

L

LarryJohnson

bertsmobile1 said:
Lucky you.
I am top poster at present because we are in covid lockdown right now.
The government failed to manage airport quarrintine properly and allowed Covid to escape , then bungled the lockdown preffering to blame the ethnic migrants .
So now we are in the 7th week of a 2 week lockdown & they are pretending to be trying to get it under control while all the time relying on increased vaccinations to initate herd immunity mcuh the same as the US & UK
So we had it licked but never underestimat the ability of a government to stuff things up
Looks like it will be christmass before I am allowed to go back to work.
And that is assuming another variant does not pop up and the immunity to the delta strain actually lasts for that long
Tis really amazing to see how a single infected person can blow out to over 3000 cases in 7 weeks , kill 14 people and have 70% of the population locked up at home .
So I for one have all the time in the world to wait for you to get back under your mower.
Click to expand...

Wow. Sorry you're out of work for awhile. This may cheer you up.
I'm a bonehead. Took off 2 hrs this afternoon because I was already sweaty. Dropped the idler set to check belt alignment and noticed it was outside one of the guide posts. Put it where it suppose to be. That solved 90% of the burning belt issue. Ran it 3 times for 15 minutes each time to cut lawn, still getting a slight rubber odor. Might just be the front idler which isn't installed yet. Waiting on a new one.


#31

M

MParr

LarryJohnson said:
Wow. Sorry you're out of work for awhile. This may cheer you up.
I'm a bonehead. Took off 2 hrs this afternoon because I was already sweaty. Dropped the idler set to check belt alignment and noticed it was outside one of the guide posts. Put it where it suppose to be. That solved 90% of the burning belt issue. Ran it 3 times for 15 minutes each time to cut lawn, still getting a slight rubber odor. Might just be the front idler which isn't installed yet. Waiting on a new one.
Click to expand...
Yah!


#32

B

bertsmobile1

Always good to hear a problem is solved.

Once a belt starts to burn it is trash so better get yourself another one as this one is now on borrowed time but no point replacing it till it goes bang.
You will remember how it goes next time


#33

7394

7394

And don't put on a new belt if you have a bad pulley or idler.

Unless you have a money tree out back.


#34

StarTech

StarTech

bertsmobile1 said:
Always good to hear a problem is solved.

Once a belt starts to burn it is trash so better get yourself another one as this one is now on borrowed time but no point replacing it till it goes bang.
You will remember how it goes next time
Click to expand...
It usually is but just a note here even new belts can have an odor to them when first put in use. In this case though we do know the belt has gotten damaged from severe overheating and should be replaced once the failed items are replaced.


#35

G

Gord Baker

LarryJohnson said:
Installed a new oem drive belt today and notice it smelled during initial test drive. Extemely hot to the touch. When replacing I noticed one of the belt guides was worn. This belt is much thicker than old after-market belt. Guides aren't bent. I rotated the worn guide , but still belt gets hot. Normal?
Click to expand...
Be sure you have the correct belt. Thicker belts need to be somewhat longer as they ride higher in the pulleys.
Check spindles and idlers for signs of seizing up.


#36

RP54

RP54

LarryJohnson said:
Installed a new oem drive belt today and notice it smelled during initial test drive. Extemely hot to the touch. When replacing I noticed one of the belt guides was worn. This belt is much thicker than old after-market belt. Guides aren't bent. I rotated the worn guide , but still belt gets hot. Normal?
Click to expand...
Something is seized. Rotate the belt by hand looking at each pulley. Or you can try to rotate each pulley if you have no tension on the belt. It is possible there is something caught around a spindle but more likely I would guess the bearings are frozen.


#37

L

LarryJohnson

7394 said:
And don't put on a new belt if you have a bad puller or idler.

Unless you have a money tree out back.
Click to expand...

There was a time yesterday when I wanted to strap the mower to a very large trebuchet and watch it FLY!


#38

J

Joed756

Are the idler arms free so that you can de-tension the belt by hand? Your comment about squeezing it in there makes me wonder.


#39

K

Kevins1955

LarryJohnson said:
Installed a new oem drive belt today and notice it smelled during initial test drive. Extemely hot to the touch. When replacing I noticed one of the belt guides was worn. This belt is much thicker than old after-market belt. Guides aren't bent. I rotated the worn guide , but still belt gets hot. Normal?
Click to expand...
The length of the belt is important, but so is the width or thickness. Usually a belt is identified with the size, along with a part number. For example, a belt that is labelled 3L320 is code for a 3/8" wide x 32" long. Make sure you are using the correct length and width for your mower.


#40

StarTech

StarTech

The OP having to squeeze in the belt in is because he didn't loosen the idlers before hand.


#41

S

SamB

LarryJohnson said:
There was a time yesterday when I wanted to strap the mower to a very large trebuchet and watch it FLY!
Click to expand...
Not everyone has a trebuchet. I'd sure like to borrow yours every once in a while!! :-D


#42

S

SlopeMan2

I did a dumb thing by putting a rear wheel on backwards once, and the tire rubbed the frame. First thing I noticed was a smell, which was a drive belt overloaded. I see you have some good drawings to study. Good luck.


#43

L

LarryJohnson

StarTech said:
The OP having to squeeze in the belt in is because he didn't loosen the idlers before hand.
Click to expand...

The OP made an attempt to loosen one of the idlers when it was removed, but couldn't figure out how to tighten once it was installed. So he squeezed the belt between the two with idler installed.


#44

S

steelwheel

LarryJohnson said:
Installed a new oem drive belt today and notice it smelled during initial test drive. Extemely hot to the touch. When replacing I noticed one of the belt guides was worn. This belt is much thicker than old after-market belt. Guides aren't bent. I rotated the worn guide , but still belt gets hot. Normal?
Click to expand...
I believe Rivets is dead on the money. I've replaced many hundreds of drive belts, idlers and pulleys in my years and one thing I absolutely KNOW is that when any part of the drive system needs to be replaced ie; the belt, idlers, and pulleys should all be replaced at the time of repair. Yes, it will cost quite a bit more but, you will thank yourself in the long run. I KNOW for a fact that a pulley or idler that spins freely has bearings that are out of grease. It only takes a few seconds for those dry bearings to heat up, expand and seize, thus the belt drags across the idler or pulley causing irreparable damage to the drive belt or worse a fire. Start it up and run it for say 30 seconds. shut it off and touch the idlers and pulleys, you'll find the culprit in a hurry!
LarryJohnson said:
Installed a new oem drive belt today and notice it smelled during initial test drive. Extemely hot to the touch. When replacing I noticed one of the belt guides was worn. This belt is much thicker than old after-market belt. Guides aren't bent. I rotated the worn guide , but still belt gets hot. Normal?
Click to expand...


#45

L

LarryJohnson

steelwheel said:
I believe Rivets is dead on the money. I've replaced many hundreds of drive belts, idlers and pulleys in my years and one thing I absolutely KNOW is that when any part of the drive system needs to be replaced ie; the belt, idlers, and pulleys should all be replaced at the time of repair. Yes, it will cost quite a bit more but, you will thank yourself in the long run. I KNOW for a fact that a pulley or idler that spins freely has bearings that are out of grease. It only takes a few seconds for those dry bearings to heat up, expand and seize, thus the belt drags across the idler or pulley causing irreparable damage to the drive belt or worse a fire. Start it up and run it for say 30 seconds. shut it off and touch the idlers and pulleys, you'll find the culprit in a hurry!
Click to expand...

Rivet concluded the bearings were worn and apparently the cause of the problem. At the time, I concluded that the pulleys were turning freely, not binding, not wobbling, and were not the cause of the heated belt. From your explaination above, I now understand why the pulleys aren't suppose to spin so fast - no grease equals fast spin. While the pulleys may be old and have no grease, it wasn't the cause of the immediate problem.

Received the new front pulley near the steering column. Wow, what a difference. That old one was more of an issue than the idler pullys.
Untitled by Larry Johnson, on Flickr


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