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This is for a 2015 model - always run pretty well, but last year there was a lot of vibration when the blades were engaged - you can see the belt vibrating a lot, especially on the left side.

The belt had a few chunks missing and looked pretty worn so I went ahead and replaced it this weekend. The vibration is still really bad and now whenever I engage the blades it seems like the engine bogs down and almost dies - it picks right back up, but the belt seems pretty violent.

I'm really not sure what the next step would be - any advice on what to check/try next?

Thanks!

Take the belt off and either remove the deck or get the mower high enough to get under the deck.
Grab each end of each blade, try to move it up & down the rock from side to side see-saw style.
Any movement = time for new bearings.
spin each one and check for smooth quiet rotation.
Again any rumbles or jerkieness = new bearings.
Have a close look at the blades
Any lumps missing, any splits or bends where they should not be = new blades + new bearings
Check the spindle housing where they bolt to the deck.
While the 4 bolt ones are a lot stronger than the old 3 bolt ones the lugs still crack or break off.

Now on top of the deck check the tensioning arm for a free smooth movement.
Check the pivot on the tension arm as it tends to wear oval.

Spin both idler pulleys again checking for smooth quiet movement .
Again any failure = replacement of the whole pulley as the bearings are captive.
Check all of the pulleys ( including the engine pulley ) for something stuck in the groove.
Tree nuts get in there and can be near impossible to remove.
While you are checking the pulleys for debris also check the flanges for dents.

Just put on new blades, so can at least remove that from the equation. I bought a mower lift to make maintenance a little easier so I will check this stuff out this weekend - or try. Not sure on this thing what should move with what amount of force.

I should also ask if the belt keeper/guide could cause a problem? At one point a couple of years ago I loosened the bolt holding that and didn't know what position it should be in - always meant to go to Lowes and take a picture of what it should look like, but pretty sure it isn't in the right spot. I had an issue around this time where the belt kept shooting itself off.

If the guide has deep wear in it then it is in the wrong position.
If the belt is on the wrong side of a guide then it will do what you describe but with lots of smoke & a burned belt.

Pulleys on the spindles can also be worn in the center hole. Check that too.

If you look at the idler tension arm on the deck there may be a hole between the two idler pulleys . If so the end of the belt guide should drop into that hole and then tighten the the nut on top of the idler pulley that holds it. Also that belt guide should face straight up and down with no angle to it. It is not uncommon for the belt to grab that guide and put a nice twist into the guide rod.

If I posted a picture, would it be possible to tell if the position is correct?

Belt guide should be straight between the two idler pulleys, in line with that square hole in the arm. May even drop into that hole.

ILENGINE said:

Belt guide should be straight between the two idler pulleys, in line with that square hole in the arm. May even drop into that hole.

Click to expand...

Up too high to fit in there. As much as I try, I cannot unloosen the bolt holding that thing on - tried both directions and barely get any movement - probably why it ended up being in that position.

Okay, so it seems they don't sell this at the Lowes around me anymore - replaced with Craftsman.

Took the belt back off and tested the blades - no wobble, but I did notice that while the center blade spins freely, the left side has a little resistance and the right has a ton, as well as being bent very slightly (see picture). I hit a tree stump last year and the blade tore through part of the deck, must have happened then.



Does the whole assembly have to be replace? I tried to remove the top part (see picture), but I'm not sure what is safe to hold onto to remove the nut.



Without the belt there is zero hesitation when the blades are engaged, so at least it isn't related to the main spinner. I know, my technical terms are great.

Edit - So, finally removed it. Not sure if it happened now or earlier, but the mandrel broke off two of the bolt holders. Pretty sure the spindle that sits on top also made its own new grooves as I had to use a hammer to remove it. Ordered all new parts and fingers crossed that is all. Afraid to remove the other two in case they crack.

Don't feel too bad about breaking the spindle housing.
If the mounting tabs did not break off then the bolts would have broken , well at least one would have.

For future reference you hold the blade to undo the pulley nut
Then put the nut back on, put a socket on the nut and relieve your frustrations with a big hammer.
Once the spindle is out you can put the blade in a vice to undo the blade bolt.
The housings stay in the deck unless you are going to replace them.
The new housing will come with unthreaded holes.
You will need a decient nut driver to get the bolts to cut a new thread .
Make sure you get new bolts with the new spindle housing, most now days come without them and the bolts are a speciality item.
I generally hold the housing in a vice then run an old bolt through each hole to cut a thread in there first the fit the new bolts with a little silver no-sieze on them.

Running with a bent blade will throw the bearings in the spindle housing very quickly.
With the spindle housing that was a little hard, do as mentioned above and when the shaft is out replace both bearings.
They are 6203 top & 6204 bottom.
Get good ones from an engineering supply store, not from Ebay or Amazon , bearings are the most counterfeited item on the planet & there are a lot of bearings out there that are total rubbish.
Stick the shaft in the fridge overnight then in the morning put the bottom bearing in a plastic bag in boiled water for 10 minutes.
Usually this will allow it to drop strait onto the shaft with little more than thumb pressure.
Chilled overnight the top bearing will drop right into the housing then leave it a hour to warm up before you push the spindle complete with blade back through.
Leave the deck in the hot sun if you like to warm the housing & bearing a little.

You can just hammer them in but there is 5/8 of SFA crush holding the bearings in the spindle and once they start to spin in the housing it is all over.

While waiting on the parts I do have another question - how do you know how much grease to put into each grease point? I have just been doing two pumps. I also know you need to grease the new spindle - I saw mention of 12 pumps there.

If the bearings are sealed , just a little.
If the bearings are open you fill the entire cavity and it takes near 1/2 pound of grease.
I do the latter and remove the inner seals on the bearings.
This makes bearing replacements very messy and you use a lot of grease.

In theory a sealed bearing in a sealed enclosure should not require any grease at all.
The commercial decks get their bearings put in dry because we change them every year .
All I do with them is coat all of the surfaces with grease to inhibit corrosion.

bertsmobile1 said:

If the bearings are sealed , just a little.
If the bearings are open you fill the entire cavity and it takes near 1/2 pound of grease.
I do the latter and remove the inner seals on the bearings.
This makes bearing replacements very messy and you use a lot of grease.

In theory a sealed bearing in a sealed enclosure should not require any grease at all.
The commercial decks get their bearings put in dry because we change them every year .
All I do with them is coat all of the surfaces with grease to inhibit corrosion.

Click to expand...

My manual says to grease all the points every 25 hours I believe. That includes the front casters and all 3 spindles.

Okay, got everything bad together. At first the thing would instantly die when the blades were engaged - I had to actually run it for a while without blades and now it seems ok.

Belt shaking is still really horrible - https://imgur.com/dDsh72Y

Full speed and then slomo.

Maybe this is normal though?

The belt run on all of the domestic Husqvarna ZTR's is very poor.
They are trying to cut costs by not having enough idler pulleys.
That amount of flapping around is unfortunately fairly typical on the cheaper units, particularly on the 2 spindle decks.
Check the tensioning pulley and see if there is an adjustment to make the belt a little tighter.
in theory the only slack & there fore flapping should be between the engine pulley & the tensioning pulley where the belt is being "pushed" and the tensioning pulley should take all this out

This is on a 3 spindle deck and no more adjustment that I could find. This only happens on that long run going to that one spindle - nothing else has such a long distance between them.

bertsmobile1 said:

The belt run on all of the domestic Husqvarna ZTR's is very poor.
They are trying to cut costs by not having enough idler pulleys.
That amount of flapping around is unfortunately fairly typical on the cheaper units, particularly on the 2 spindle decks.
Check the tensioning pulley and see if there is an adjustment to make the belt a little tighter.
in theory the only slack & there fore flapping should be between the engine pulley & the tensioning pulley where the belt is being "pushed" and the tensioning pulley should take all this out

Click to expand...

Are you sure you have the belt run correct ?
usually there is a diagram on the deck and another in the owners manual.
Some times the two are different because changes get made or plain old mistakes
Every spindle pulley should have belt contact for 1/2 of its circumference .
Idlers oft only just touch.

Yes, they are correct. The manual and the deck diagram are the same.

bertsmobile1 said:

Are you sure you have the belt run correct ?
usually there is a diagram on the deck and another in the owners manual.
Some times the two are different because changes get made or plain old mistakes
Every spindle pulley should have belt contact for 1/2 of its circumference .
Idlers oft only just touch.

Click to expand...

Seems the final issue is from my replacement belt not fitting. While it may be the same length, the rest of the dimensions don't seem correct and so the idler pulley is hitting the frame.



Edit: So, not final. Old belt on and have good clearance, but the belt barely moves. When I engage the mower I get sparks. Can't see what exactly is happening, but pretty sure the pulley is still being jerked back. Took off the belt and noticed the clutch assembly now barely moves - it takes a ton of force just to spin it a little. I took it off, but have no idea how to actually get it open to see the issue or if it is even something I can fix.

Just keep digging the hole deeper.

Electric clutches have a brake fitted to them.
Legal requirement to make the blades stop after "X"seconds / rotations when turned off.
If the pulley is fouling on the deck then the routing is wrong, the belt is too long or the tensioner arm pivot is flogged really oval
The idler pulley should not come anywhere near the frame.
The tensioning spring should move the pulley towards the other pulleys.
Are you sure that the arm is on the right way round.
The spring should pull the short end of the lever left ( sitting on the mower ) towards the frame causing the pulley to move right towards the other pulleys and the belt prevents this happening.

Pretty sure it is on the right way - same way it has been for a number of years.

I did find that the clutch was seized because I tightened the 3 screws around it. I guess when those are loosened or tightened it controls how much force it takes to spin. Loosed up all the way and even after the blades are disengaged the wheel keeps spinning. Too much and it doesn't move. Have it somewhere in the middle right now. Still having the issue of the idler puller slamming against the frame though. If I start the blades at the highest position it is much better, but on the lowest setting it is just a hair away.

bertsmobile1 said:

Electric clutches have a brake fitted to them.
Legal requirement to make the blades stop after "X"seconds / rotations when turned off.
If the pulley is fouling on the deck then the routing is wrong, the belt is too long or the tensioner arm pivot is flogged really oval
The idler pulley should not come anywhere near the frame.
The tensioning spring should move the pulley towards the other pulleys.
Are you sure that the arm is on the right way round.
The spring should pull the short end of the lever left ( sitting on the mower ) towards the frame causing the pulley to move right towards the other pulleys and the belt prevents this happening.

Click to expand...

You should not touch the 3 screws on the clutch unless necessary.
They adjust the position of the clutch plate.
Most are around 0.010" between the clutch plates.
When you remove the belt does the tension arm move across to the right side & almost touch the other pulleys ?
If not then the deck is not set up right.
If it does do that then you have excessive wear in the pulleys or a belt that is drastically too short

Far too late for not touching them. Any idea how freely the clutch should spin? Might help with adjusting them back.

Yes, without the belt the arm moves and sits next to the other pulley.

I found out the problem with the belt wasn't so much that it was too short, but that the dimensions of the belt angles are wrong so it doesn't sit against the pulleys as well. That adds up over each pulley and then causes it to pull too much.

bertsmobile1 said:

You should not touch the 3 screws on the clutch unless necessary.
They adjust the position of the clutch plate.
Most are around 0.010" between the clutch plates.
When you remove the belt does the tension arm move across to the right side & almost touch the other pulleys ?
If not then the deck is not set up right.
If it does do that then you have excessive wear in the pulleys or a belt that is drastically too short

Click to expand...

veekay said:

Far too late for not touching them. Any idea how freely the clutch should spin? Might help with adjusting them back.

Yes, without the belt the arm moves and sits next to the other pulley.

I found out the problem with the belt wasn't so much that it was too short, but that the dimensions of the belt angles are wrong so it doesn't sit against the pulleys as well. That adds up over each pulley and then causes it to pull too much.

Click to expand...

The clutch won't spin freely because of the brake. Next to each of those bolts on that clutch should be a slot about an inch long. You insert a .012-.016 feeler gauge between the two rotating plates and slowly adjust all three bolts to get the same clearance between the plates all the way around. Don't change each bolt more than about 1/4 turn at a time because when you adjust one bolt it will effect the clearance on the other two.

Thanks - glad I actually own a set of feeler gauges.

ILENGINE said:

The clutch won't spin freely because of the brake. Next to each of those bolts on that clutch should be a slot about an inch long. You insert a .012-.016 feeler gauge between the two rotating plates and slowly adjust all three bolts to get the same clearance between the plates all the way around. Don't change each bolt more than about turn at a time because when you adjust one bolt it will effect the clearance on the other two.

Click to expand...

veekay said:

Thanks - glad I actually own a set of feeler gauges.

Click to expand...

My reply should saw 1/4 turn at a time not a full turn at a time. Went back and edited my original reply.

veekay said:

Far too late for not touching them. Any idea how freely the clutch should spin? Might help with adjusting them back.

Yes, without the belt the arm moves and sits next to the other pulley.

I found out the problem with the belt wasn't so much that it was too short, but that the dimensions of the belt angles are wrong so it doesn't sit against the pulleys as well. That adds up over each pulley and then causes it to pull too much.

Click to expand...

Sounds strange.
Husqvarna use standard A & B profile belts however you must use wrapped belts, not standard raw V belts like a car fan belt.
These get sticky when they get hot and will not run clean for the short time till they break.

I ordered an original belt versus the generic one. I did at least get things going enough to mow today. I can't engage the blades on the storage (highest) setting, but the others work well enough.

I wasn't able to get the clutch bolted in as tightly as I'd like since there is nothing to lock into place when tightening the bolt.

Remove one spark plug and rocker cover.
Rotate the engine so that cylinder is bottom dead centre on compression stroke.
Feed as much nylon rope ( plated rope is better ) down the plug hole as you can then rotate the engine to compress the rope.
That will hold thee shaft while you tighten the bolt the turn the engine back a little and pull the rope out.

bertsmobile1 said:

Remove one spark plug and rocker cover.
Rotate the engine so that cylinder is bottom dead centre on compression stroke.
Feed as much nylon rope ( plated rope is better ) down the plug hole as you can then rotate the engine to compress the rope.
That will hold thee shaft while you tighten the bolt the turn the engine back a little and pull the rope out.

Click to expand...

Thanks. I have to ask though, what does a rocker cover look like?

It is the tin cover on the end of each head that you take off to check the valve lash .
You need to do that so you can see the valves to work out if the piston is on compression ( both valve closed ) stroke.
So while you are there, check the valve lash at 1/4" past, should be around 0.004"

Got my correct belt. I adjusted the clutch as noted, but think it may still be too loose. How freely should it spin when turned? The clutch as well as all the blades turn very easily with the belt attached. It also takes a while to stop the blades once disengaged. Too loose?

I also noticed when I replaced the belt that the other one was almost shredded in half - this after just two hours.

Got everything back up and running pretty perfectly. I apparently adjusted the clutch wrong and didn't measure between the two actual plates and instead measured between a plate and the metal frame, which made things super loose.