How would you solve this problem. Mower belts rubbing.

[4570Man]

Why not go back to the original design with a stacked center pully?

Well I could but I’d have to buy 2 more pulleys. I swapped because the drive pulley was worn out and another was busted so swapping to the double fixed those issues. Even if I did swap it back to stacked pulleys it would only help the problem not fix it. The motor is a horizontal shaft diesel with a non adjustable set of idlers to divert the belt to vertical.

 

[SPYDERLK]

I replaced the center pulley on my mower with a double pulley and got rid of the stacked center pulley which reduced the clearance. Now the belts rub against each other. Even before swapping the pulley the belts rubbed against each other evident by the abnormal wear on the belt. I’m thinking some rollers to hold up the brown belt would help but the roller of such small diameter would be spinning at a smoking fast rpm and probably wouldn’t last long. Any other ideas? ATTACH]594984[/ATTACH]View attachment 594985View attachment 594986

Cant you cant the tensioner pulley to lower that belt segment?

 

[rangerfredbob]

I had misunderstood what the top belt was before... if you can lower the tensioner pulley by about 1/4" that should help I believe

 

[4570Man]

That might be a possibility but evident by the rubber burns on the deck the lower belt is already slapping the deck.

 

[4570Man]

I’ve adjusted on it some more and raising the pulley an inch makes enough clearance but then it makes the lower belt rub tensioner bracket. There’s no position to eliminate both problems. Tilting the tensioner bracket makes no difference because it doesn’t control the second part of the lower belt. I guess I’ll have no choice to go with the roller idea which I don’t like or put separate pulleys back on which is probably what I’ll do.

 

[SPYDERLK]

I致e adjusted on it some more and raising the pulley an inch makes enough clearance but then it makes the lower belt rub tensioner bracket. There痴 no position to eliminate both problems. Tilting the tensioner bracket makes no difference because it doesn稚 control the second part of the lower belt. I guess I値l have no choice to go with the roller idea which I don稚 like or put separate pulleys back on which is probably what I値l do. View attachment 595093

Referencing this picture:

You have the tensioner bracket pivoting on a stud and the tensioner pulley pivoting on a bolt in the bracket. I think the bracket should be bent downward as closely as possible on the righthand side of the pulley pivot. This would position the side of the bracket, where the spring is, lower than now, and the resulting downward angle would cause the exit side of the pully - and thus the belt - to be lower.​

You probably will have to space the pulley downward a little so it doesnt rub on the bracket right side due to the new aspect caused by the bend.

 

[4570Man]

Both belts cross the other belt twice forming a square. The tensioner has no affect on the back section of the lower belt and it also rubs.

 

[big bubba]

simple obvious question. have you checked the idler pulleys for bearing wear? experienced misalignment/ belt rubbing when idler bearings were shot. don't understand why idler pulleys don't have grease zerks like the spindle drives.
sorry for stating the obvious, am sure you've checked

 

[4570Man]

The idler is good. The idler can’t completely fix or cause the problem anyway.

 

[Dave M7040]

From what I see in the photos and from my experience, the idler pulley is not running flat.

If the idler pivot has any wear, then the spring and the belt cause the idler to tilt off horizontal.

Many idlers use a shoulder washer. .

I do not see one on yours but this pivot, however designed, is the weak point allowing the belt to run off the center on the idler which is what I think I see on yours.

On one mower, I used a spindle assembly upside down to have a pivot for the idler which had no up and down flex.

Dave M7040