FYI- How to repair/replace bearing on an idler pulley on your mower, etc...

[padawan]

This little project came about after viewing a YT of a Gent doing the same...

Problem, bearing in idler pulley started to go. Pulley is basically riveted and spot welded together and uses a standard 40mmx12mmx7mm bearing you can pick up at any parts store or on-line for about $2-3. The mower dealer wanted $35 for a complete pulley. "Its not serviceable".

So, after drilling out all the rivets and welds and using stainless 1/4-20 x 1/2" bolts and nylock nuts, I have a serviceable pulley. I couple coats of flat black makes it look all new again. Our mowers have 3 of these pulleys each so it will pay off. The 'inner' ring was rivets, the 'outer' ring was spot welds. Probably have about $8 in parts. Thought I would pass it along to maybe help someone save some $.

 

[tmschuller]

Thanks.. Pulling the deck off my husqvarna rider 16.. Will see if I can use your fix..
Parts are not cheap or available.. Always have to order online. It needs new idler pulleys. Thanks again.

 

[padawan]

Thanks.. Pulling the deck off my husqvarna rider 16.. Will see if I can use your fix..
Parts are not cheap or available.. Always have to order online. It needs new idler pulleys. Thanks again.

If its the bearing, break/split the pulley down and look up the number on the side of the bearing. I'll bet NAPA or another parts store has them.

 

[yepthatsme]

I noticed that the bolt pattern wasn't quite symmetrical. Does that have any effect on the balance of the pulley? I realize that the pulleys are small and balance isn't that big of an issue, but I was wondering if you could see bouncing of the belt or pulsing of the pulley when it is engaged?

 

[russc2542]

I noticed that the bolt pattern wasn't quite symmetrical. Does that have any effect on the balance of the pulley? I realize that the pulleys are small and balance isn't that big of an issue, but I was wondering if you could see bouncing of the belt or pulsing of the pulley when it is engaged?

The ID-OD geometry is the same so you won't see any pulsing or bouncing till the off-balanced-ness damages the bearing enough to have play.

 

[yepthatsme]

The ID-OD geometry is the same so you won't see any pulsing or bouncing till the off-balanced-ness damages the bearing enough to have play.

If the pulley is used on the engagement arm or tensioner arm, an imbalance could cause a bouncing of the belt or a pulsing of the belt. I have seen this happen before with poorly built pulleys. Most of the time it is slight and won't have any effect on the belt operation. However, if it's severe, it could cause the belt to jump off the pulley and wedge between the pulley and the guard.

In no way am I criticizing repairing and reusing pulleys, I was just curious if the pulley worked well since it had an irregular bolt pattern.

 

[padawan]

If the pulley is used on the engagement arm or tensioner arm, an imbalance could cause a bouncing of the belt or a pulsing of the belt. I have seen this happen before with poorly built pulleys. Most of the time it is slight and won't have any effect on the belt operation. However, if it's severe, it could cause the belt to jump off the pulley and wedge between the pulley and the guard.

In no way am I criticizing repairing and reusing pulleys, I was just curious if the pulley worked well since it had an irregular bolt pattern.

I noticed that too. The inner circle is round where the rivets were but the spot welds are definitely not. We'll see tomorrow when I put it back on. I'm hoping its not noticeable. Its on a 4" idler arm on the pump drive on a Scag Turf Tiger. I'm hoping the low mass of the outer bolts compared to the overall mass of the steel pulley is negligible. I guess in hind site, I should have re-drilled the outer circle to be round. I might do that. I'll let you know.