Mower deck Husqvarna Z254 - belt shakes very badly and engine tries to die when blades engaged

[bertsmobile1]

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.

 

[veekay]

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.

 

[bertsmobile1]

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.

 

[veekay]

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.

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

 

[veekay]

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?

 

[bertsmobile1]

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

 

[veekay]

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.

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

 

[bertsmobile1]

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.

 

[veekay]

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

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.

 

[veekay]

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.