Lawnmower repair question.....

I have an older Cub Cadet i1046 zero turn mower. This thing has served me very well and I would like to try to troubleshoot it. It is long in the tooth so spending a ton on repairs is counterproductive, but wanted to get your thoughts.

I replaced the oil, fuel filter, air filter, and battery fall 2019. Ran fine until last week. I was picking up a ton of leaves and it got bogged down a couple of times. On the last pass, the deck belt slipped off the pulley. No problem I thought. I parked it (it still drives fine, blades just don't engage). Last night I pulled the deck off, replaced some of the older hardware on the deck and put the belt back on. I installed the deck and started it up thinking it was going to be an easy fix. Pressed the PTO button and heard the click but blades still didn't engage.

Here is what I have found:
1. All attachments seem to be intact. I was thinking maybe the belt slipping off may have disconnected / torn a wore but that all looks fine to me.
2. The PTO switch works. When I try to start the mower with PTO switch on, it will not start. Turn it off and it fires right up so I know the switch itself is good.
3. PTO fuse is good. I pulled it an inspected it - no issues there.

I have come to the conclusion that I may have burned the PTO clutch up by bogging the mower down. Is that a likely possibility? I ordered a new one from Amazon for $175 and will try to replace and test - if that doesn't work I can always return it.

Anyway, am I on the right track? Overlooking something simple? Any advice is appreciated. I am a weekend wrencher but like to get advice of people much smarter than me. Thanks in advance.

Take Care,
Shawn

 

Before purchasing a new PTO, see if you are getting power at the plug where the PTO wire plugs to the harness (machine on and PTO switch engaged). If so, and assuming the ground wire is not damaged, then you're probably looking at a new PTO. You could also test it by running a jumper wires to the PTO.

 

Ok thanks for that information. If I am not getting power to the PTO, what would the alternative repair be? Like I said the wires and fuses all seem to be good. There is an audible CLICK when I pull the PTO switch but as I said nothing engages

 

A "click" might be a solenoid making a vain effort. I would expect an authoritative "clank" if the clutch is actually engaging.

If you can see the drive pulley and electric clutch, watch it while someone else works the switch. You should be able to see some movement to indicate the clutch is actually engaging. If it ain't moving, then you probably don't have power to the clutch (which you already suspect); use a multi-meter to check voltage at the clutch connector with the switch "on". Work backwards to find where power is first available with the switch on. Wires typically don't fail, so the next interesting part would be the solenoid (if it has one); the coil side may be working fine (the click), but the contacts on the power side may be burned up.

If you have power at the clutch connector terminals, then you've smoked the electro-magnet windings which will require a new clutch.

 

Thanks so much, I will report my findings after trying this. I appreciate you all taking the time to post and help me out

 

When you're looking for movement on the clutch, it isn't going to be much, maybe a plate moving as little as 1/16".

It will be more positive if you can actually get your hand on the clutch. You will feel vibration if the clutch is actuating. (The engine does not need to be operating, and should not be running for this testing. If there are safety interlocks to keep the clutch from operating unless the engine is running, butt in the seat, e-brake off, you'll have to discover those.) Just rest your hand lightly on the clutch housing top or bottom, or the engine shaft; don't grip the outside diameter of the clutch, you could may get skin pinched if it really actuates.

 

Ok so I got my wife to sit on the mower and engage the clutch - it spins like a champ. The belt is not tight enough and the clutch spins freely because the belt is loose. I am unsure how to tighten the belt assembly.......I can’t find the manual at the moment so wondering if any of you have an idea how to tighten it. I assume it would be the tensioner pulley......

 

Here is the picture of the deck:


The top left tensioner pulley has a ton of play in it and moves freely toward the middle pulley, so the spring just pulls those pulleys toward each other. It seems there should be a stop on the deck that doesn’t allow that play and should keep constant tension on the spring that just isn’t there......

 

Check to make sure you have free/full movement of all sprung pulleys, belt around all pulleys and if belt is correctly routed. My .02 cents

 

Yep, all pulleys move freely. And I am sure belt is routed correctly. I will take the tensioner pulley assembly apart tomorrow and see what I can find out

 

Buy a new deck belt. They get thinner as they wear and can stretch when heated up with big loads.

With engine off and belt off PTO pulley, engage the PTO. Is pto pulley engaged to the engine now? With PTO disengaged, the pulley should rotate freely by hand.

 

That’s a brand new deck belt.....I will try that sequence tomorrow when I get home from work. Thank you

 

You're going to need the manual. Your deck appears to have linked idler pulleys tied together by spring tension. My John Deere 54" deck has the same belt routing, but only one tensioner pulley that is spring-loaded, the other is stationary. With the information off the mower, you can online and find the manual here: https://www.cubcadet.com/en_US/operatorsmanuals

 

So if you look at the diagram in the manual, the spring attachment for the tensioner pulley is supposed to be more pointed “north”. It seems that it is pointed closer to “east” on my deck. I will inspect the entire tensioner assembly tomorrow and hopefully find a way to reinstall the pulley bracket correctly but suspect there must be some “check” on one of the brackets that had sheared.

 

There aren't any "stops" on the deck. Belt tension is what "stops" tensioner over-travel. I suspect either the end of spring, Item 29, or retainer, Item 10, are either broken or lost; i.e. the end of that spring isn't connected to anything. Alternately, you could have reattached the spring to the wrong point on the deck after the belt came off.

The manual diagram shows that spring (Item 29) attaching to the deck under the middle blade pulley, but your pic shows it pointing to the center idler pulley, a difference of about 60 degrees. That spring should be pulling the outside idler pulley toward the center of the deck to tension the belt.

Edit: I misread the drawing. Their assembly diagram actually shows Item 29 pointing to the idler pulley. Everything else I said is correct. The outside idler should be under spring tension pulling it toward the center of the deck. If it's not doing that, the reason it's not doing that is the problem. If the outside idler is under spring tension, and you have the belt routed as shown with the flat back side of the belt running on the idlers, and your belt is still too long...you need a new belt.

Once you repair that spring, the correct way to install the belt is to use a breaker bar and socket on the nut on the outside tensioner pulley bolt. Position the breaker bar on the side of the outside pulley nearest the rear of the deck, and pull like you're tightening the nut. The arm mounting the idler pulley should pivot outward, creating slack in the belt allowing you to install onto the drive clutch. The tapered sides of the belt ALWAYS face into the groove of the drive clutch pulley and blade drive pulleys; the flat back side of the belt runs on the idler pulleys.

The other spring for the inner idler pulley is correctly positioned. The inner idler pulley may adjust as force is applied to the outside idler, but it is just along for the ride.

 

Thanks so much; the spring to the outside pulley was broken. It still looked like it was connected but it was compromised at the idler bracket connection and would not hold tension when the belt tried to engage the blades. I had a replacement spring and that fixed it temporarily. The hole that the spring goes into on the idler bracket has a wear line that is almost like a straight line spanning almost the entire piece. It’s only a matter of time before that wears through so I ordered a new bracket and will replace. Here’s to hoping I can get the last of the leaves up this weekend!!!!