48" Deck Belt Tensioner

[CubanB 4]

At the start of the mowing season I kept having the belt on the deck pop off.the center blade would still spin from the PTO belt and the outer two would stop. I'd have to take the covers off and just force it back on one of the side pulleys. I figured belt was worn and stretched.got sick of taking covers off so I left them off.since then I've mowed about 20 hours and it hasn't come off again. I noticed at the very end of my last mow, the engine was really blogging down, and I could hear a metallic noise when engaging PTO.

 

As you can see in the video, thr idler pulley is rubbing up on the nut for idler plate. I found a few pictures on here while searching and they all show that same nut a good 2 inches from the idler pulley.

 

I preemptively ordered a new tensioner spring and I have a spare deck belt. Is that all I will need to remedy this? I haven't taken it apart yet but I took the deck off the mower.

I can't figure out what the root cause of this  would be,and would like to know if anything else should be considered for replacement. I think maybe the idler pulley?

 

Hey guys, I was wondering of anyone has had a similar issue and what they did to fix it.

 

Here is a video with the PTO engaged with engine at idle.

 

https://1drv.ms/v/s!Atlwbji1O0hyhaMPoXvfrbFFHs20wQ

 

Thanks In advance for any thoughts/suggestions.

[peter lena 8,625]

@CubanB would bet , wrong belt , and INCREMENTAL BEARING HANG UP  ,  original idler pulley ,  known for failures , all of my deck idler pulleys , have bigger bearings , and  lucas chassis grease . there is an entire upgrade on this common issue . that constant bearing issue is what fractures decks , tractor supply has a similar pulley , with a larger  bearing , had to put a 3/8 sleeve into the 5/8 bearing hole , also cleaned out and re greased the bearing , never trust original lube , BTW  the mule drive bearings , also like a lubricant change , pto cone needle bearing , pete 

[Ed Kennell 38,170]

You need to correct this before the pulley is damaged.   Get a shorter belt or some of the slide bars have two holes where you can reposition the pulley away from the bolt.

Remove any sharp edges and burrs from the pulley before running your new belt.

 

 

Oh, to the 

Edited August 11 by Ed Kennell

[clueless 2,991]

Not the correct belt. 

[CubanB 4]

The belt was correct, however several years ago when I bought this mower,the tension spring broke. I took it to a local hardware store and got the closest one they had,and it seemed to work. I think it was a little longer and less forceful.

 

I began disassembly and cleaning. I ordered a new idler pulley, and the plastic spacers. I realized after that it is leaking oil. I will need to correct that, appears to be leaking near the filter.

 

The idler support bar is quite worn. My question now is can I continue to to use this or is that a bad idea?

[CubanB 4]

Cleaned everything up and looked for oil leak. Right at the filter. Grabbed it and was able to give it two full spins to tighten it.

 

Now I suppose I will be fixing up this deck. Decided to order the idler bar as deck is in great shape overall. Holding the new and old in hand, the difference is substantial..

[lynnmor 7,305]

4 hours ago, CubanB said:

Cleaned everything up and looked for oil leak. Right at the filter. Grabbed it and was able to give it two full spins to tighten it.

 

Now I suppose I will be fixing up this deck. Decided to order the idler bar as deck is in great shape overall. Holding the new and old in hand, the difference is substantial..

So you actually use the hood for a work bench?

[Ed Kennell 38,170]

On 8/11/2024 at 3:53 PM, Ed Kennell said:

Get a shorter belt or some of the slide bars have two holes

Like I said before, move the pulley to the hole near the center on the slide bar so the pulley is not hitting the bolt.   This may require a shorter belt

This is why I only buy belts locally at TSC.  If they don't fit, they can be exchanged or returned for a full refund.

[Lane Ranger 10,968]

I think the tensioner spring you purchased as a replacement was probably the culprit that led to the walloring out of the idler bar.   I had  a similar repair several years ago on a 42 inch deck that had the nylon inserts in the deck loose which allowed the bolt to eat out the sides of the hole in the idler bar.  Bought a new idler bar like you but also a new Toro idler bar spring.  Like Pete Lena says the idler pulley bearing is kind of a weak spot on the deck.  Always check and consider renewing when you have to change any deck parts.

 

The overall tension has to be just so so for the deck to function correctly and last a long time.   Like you indicate you have a good deck .

 

 

Edited August 15 by Lane Ranger

[Brockport Bill 1,662]

Replacing a torsion bar that has worn slots as well as the plastic washers is always a wise decision 

[CubanB 4]

Thank you all for your help. I have replaced the idler bar, pulley, and spring with new OEM parts. Brand new belt as well. The old belt was more like a piece of rope, it was rubbing on something. Hopefully I will get many more years of use out of it!

[Ed Kennell 38,170]

Looks great.    Good to see you moved the idler pully away from the slide bar bolt. 

     I like to attach the spring thru the center of the hole.    I feel it puts less stress on the spring hook that causes them to break.

 

   Yours

 

Mine

 

No biggy, but it may make your new spring last for 50 years instead of 20.     

[peter lena 8,625]

@Ed Kennell totally agree on the spring placement , ensuring its action /  survival , usually pick up a  change point when i,m  snooping around an issue . pete