Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

Drive belt wear

Any ideas what could be causing the drive belt wear seen in following pictures?

http://picasaweb.google.com/audreyappliance/WornDriveBelt?authkey=TpuWljxHp0o&feat=directlink

Sorry some pics blurry. I also pulled belt off to side of pulley so you could see some of the wear.

I did have some slow speed engagement problems earlier that I was able to address by adjusting the drive control rod. It seems there was too much slack. I haven't had any engagement issues since and I suppose this wear could've occurred before the adjustment of drive control rod.

One theory I have is that clearance of the traction drive pulley in regards to the friction drive might be too far apart and causing this wear. If drive pulley is pulled closer to wheel the belt wear may be mitigated on that one side of belt. Visually looking down at drive pulley I see belt rides that one side of pulley in the drive disengaged mode. In drive engaged mode it appears they line up correctly. This blower doesn't have any belt adjustments. They tell you to just replace the belts when they are worn or broken.

Service manual says the following on clearance:

"the disengaged position adjust the clearance between the Rubber Wheel Ring and the Drive Plate Assembly to .125"-.140". "

This is adjusted from from where the control rod attaches to lower left side of rear frame body by a spring. There is a nut that can be adjusted on the clutch rod.

I usually only plow in lowest gear and don't really push it. Auger belt is perfect. I intend to monitor the wear to see if it gets worse or stays in holding patter. I do have spare belts. It seems only about half of the belt has this wear so at some point there was some slipping that occurred on about half of it. The other half on that side is in good condition.

Drive engagement works perfect too.

Thoughts? Let me know if I need to clarify anything.

Thanks!
Snowmachine

I looked at your pics.  From what I can see, the fraying seems to be the result of contact with something on the outside of the belt.  When you disengage the drive, the belt will still be traveling but not right in the pulley groove.  It tends to bounce out of the groove when the drive is released.  When it does that, the belt could possibly be lifting enough to make contact with something.  Take a look at those two bolt heads just above the pulley (photo 1).  See if there is some buffing or shining on the underside of one or both of them.  If not there, look for other areas where contact on the outer surface of the belt could happen.  I noticed that on the inside of the belt there is a little lap hanging down a bit.  it's more than likely a manufacturing left over.  Take a torch a lightly melt it or burn it off.   If you find that the belt is lifting too far out of the pulley, adjust the guide fingers just a little to keep it closer to the pulley.  Don't give it too much adjustment.  Just a bit is all that's required.  When you've done that, take that torch and melt the fraying on the outside of the belt.  Make sure you don't have any gas leaking anywhere when working with an open flame.  Know what I mean???

Take a look and let us know what you see.

One last thing.  When taking close up pics, use your macro focus setting. 

Thanks Borat!

I will check into what you suggested.


I did have camera on macro but it acts kind of flakey on this camera when other things are nearby. I need to probably play with camera settings at some point for a workaround.

snowmachine wrote:
When using macro setting, try to brighten up the subject.  Even if you're using a flash, shine a light on it.  When you partially depress the button, the aperture should close down and allow for sharper images.  At least that's how mine seems to work.   

Interesting that the wear is just on the back side of the drive belt..  Get a helper to engage the drive and dissengage the drive with the cover off see what it is hitting.  In the archery days when we were tuning bows to see where the arrow would be contacting the arrow rest, we would spay foot powder all over the rest then shoot the arrow through the rest and if the arrow made contact with anything you would see it in the marked or rubbed powder.  You might want to spray and engage and see what exactly that belt is making contact with.  Those bolt heads could be prime targets, but you also might want to check the back of that drive pulley itself to make sure nothing is sharp there.  Good luck and let us know what you find.

Rick

I pulled everything apart this morning and couldn't find anything that it appeared to be rubbing on. I re-adjusted the traction drive pulley to make it more inline with the engine pulley and idler but shy of touching the friction disk while disengaged.

I took a small torch and cleaned up the side fraying and the lap piece that was hanging down.

This was good routine for me anyway since I had not torn machine down to this level before. A good run through on the belt replacement routine.

After running her a while this morning I rechecked and nothing noticeable had changed on belt in a negative way. I probably won't know for a couple more uses. If the adjustment I made is not the solution them the drive pulley itself may have some sharp edge on it.

I'll keep you posted... unfortunately no smoking gun on solution yet.

Thanks!

Personally, I think the belt is getting frayed on the two bolt heads just above the pulley.  All of the abrasion I could see in the pics is on that side  and apparently on the back or outer surface of the belt.   It looks as though the belt is slack enough when not under load to contact the bolt heads when power is relieved from the drive.  Have you tried to run the machine, apply power to the belt then relieve it to see what happens.  You might have to jack the wheels off of the floor and put a box or something under the machine to do an effective test.  Now that you've had it apart and re-assembled, you may have made enough of an adjustment to eliminate the problem.  I'm interested to hear if it starts again.  Let us know. 

It may be. I am not ruling anything out at this point.

While not running the belt tension seems about the same from this belt whether drive is engaged or disengaged. That spring loaded idler pulley seems to keep the same amount of tension on it at all times.

Do most friction drive snowblowers like the 14.5 keep the drive plate spinning in both drive engaged/disengaged mode? Drive engagement then just moves the already spinning plate against the friction disc?

I do need to a running test to see if I can see the belt jump between power drive engage and disengage.

Thanks!

borat wrote:

I may need to do that trick with the foot powder if nothing else turns up a clear solution... hopefully like Borat suggested I may have solved my problem with disassembly/reassembly. Time will tell. I had her tear into some compact snow and ice today. It seemed to slice through it pretty easily.



Clay wrote:

If you try the foot powder thing, incorporate Borats idea of lifting the wheels off of the ground.  A floor jack would be perfect, but there are many ways to suspend the wheels off of the ground from a piece of firewood that you have handy to a concrete block.  That way you won't have to walk around after it and you can isolate that probablem easier.  If you do it inside of your garage, make sure that you have enough ventilation while running that engine.  What is nice is that access to those two belts are a matter of just undoing two bolts and pulling the cover.  I'll keep watching this one.

Rick