Shredded primary belt

[Evil Twin]

I'm new to the forum. This is my first post, so please bear with me. I just purchased a home on a large lot and a Husqvarna YTH2548, 48" lawn tractor, was included with the purchase. I'm in the process of tuning up the tractor as I'm not familiar with what, if any, required maintenance was completed by the previous owner. I replaced the three spindles (from Amazon), the three belts, and the three blades. My concern is withe the right hand spindle, the one with the double pulley, On the new spindle, the top pulley seems to set about 1/4" too high causing the primary belt to rum on the deck lowering bracket arm. There seems to be sufficient clearance when the mower deck is lowered, but when the deck is fully raised the belt rubs on the lowering arm. The new primary belt shredded after about 20 minutes of use. The only thing that I can figure that may be the cause is the spacers between the spindle and the pulley may be thinker on the new spindles? I won't know for sure until I can disassemble the deck again. Could this be solved by using the old spacers and nut?

 

[bertsmobile1]

Check the deck height of the deck.
Owners who let their grass grow too long sometimes adjust the height too high.
Also check the front drag link support.
If you have the singe drag link the support bracket gets bent backwards which drastically alters the geometry of the deck.
I regularly have to pull them out and bend them forward .
If yours is held i by the front axle cross member then just raise the mower high enough to get some 12" shifters on the bracket and bend it forward.
If your bracket is bolted on with 2 small bolts take it off as attempting to bend it will rip it out.

 

[StarTech]

I check to see what the height of the pulleys should be in reference to the deck in the morning as I just got in a YTH2448 Saturday morning. It can very well be a spindle setup problem especially if you got after market spindles with pulleys. I had 6 spindles only assemblies two years ago that had over 1/8 end play and also sat 1/8 too high. What a pain when you doing a rush job. Ended having to rebuild the old spindles once I found the tapered bearings.

Also you are using Kevlar belts as Poly belts on this mower will fail quite fast.

 

[StarTech]

Okay the double pulley deck height to top of the stack is 3-7/8" from deck. The double stack itself is 2-1/32" top to bottom. Looking at the deck I realized that your problem may not be the double stack instead being the idle arm as I have both the arm and the stepped washer at the pivot to wear heavily. Sometimes even the deck in the same area is worn. All this causes the idler pulley to ride higher when under the belt load and spring tension. I have replaced numerous of these stepped washers and idler arms. Also check the idler pulley itself for bearing wear. Plus make sure the PTO to Deck belt is 5/8 X 90; don't install a belt that is under 89.5" as if shorter as it will cause belt life problems. Just a few thoughts.

 

[Evil Twin]

The double pulley deck height to top of the stack is 4" from deck. It's 1/8" higher than yours. The double stack itself is 2-1/32" top to bottom which seems to be consistant. I feel no end play in the spindle. The spindles are from Amazon. They are KanSmart 285-108 Spindle Assembly w/Screws for AYP Husqvarna. Is it possible to run the spindle without the spacer or is it better to purchase an OEM spindle?

 

[StarTech]

You got at least a thin spacer so only inner part in the top spindle is covered for free rotation. I believe your problem is the idler pulley bracket tilting (canting) and raising the drive belt higher than normal. This caused by the previously mention wear.

 

[bertsmobile1]

Hi & welcome to the forum.
When seeking assistance it is a great benefit to the rest of the forum if you could post the actual model number which is displayed on the ID tag.
Usuallt it will be under the seat on the frame ; on the left side frame rail under the foot board or some times on the back under the fender .
This helps us greatly as we can then zero in on the exact same mower as many models ran for a long time with a lot of variations.
Also as this is an old used mower there is no guarantee that how you found it is how it should be.
We did not get this model down here so I have no access to the IPL other than from one of the on line parts retailers which can be a little problematic.
So for starters is this the deck that you have https://www.jackssmallengines.com/j...mower/yth-2548-b-954571984-2004-06/mower-deck ?
IF so then again it gets rid of ambiguity if you use the reference number from the diagram so we are all talking about the same thing.
The only time I have seen one of these decks cause the belts to foul bad enough the wreck them in no time flat was when one came in with the spindles mounted on top of the deck, not under it.
What looks right is to have the flange sitting on top of the deck with the bolts just holding it in position not the flange under the deck where all of the weight appears to be on the flange and I have seen this done on more than one occasion.
You mention "Spacer " by which I assume you are talking about # 31 and not # 16.
Part # 31 is essential as it gives running clearance between the bottom of the spindle pulley & the top bearing.
Also note that all 3 spindle pulleys need to be in the same plane so if one goes then all 3 must go and then there is the height of the idler pulleys to be considered.
Is the sway bar # 6 still there , they hae a habit of falling off then being left off , Also check that the mounting plate # 3 is still bolted securely to the frame by both bolts.
If not it can allow the deck to shift under load enough for belt contact tho be made .
And as previously mentioned make sure that the 2 PTO idlers are in good condition, in particular the tensioning pulleys as the arms # 43 & # 146 wear under the pivot washers # 42.
This allows the arm to lift and the belt to run higher than it should.
Also check that they the correct pulleys . Some are stupid prices so cheapskate owners find a cheaper one that is "almost the same."
These pulleys have stand off bushes through the center and the same size pulley might be supplied with a dozen or more different height stand offs which will also alter the running height of the belt and a different diameter belt will alter the actual belt run.

 

[Evil Twin]

I'm new to lawn tractor ownership, so forgive me if I'm using the incorrect terminology. Yes...this is the deck I have, the one that's pictured on the Mower Lift diagram that you posted. My primary belt is rubbing on the bottom edge of part # 53 (532175802 ARM SUSP REAR RH). The primary belt touches and rubs on the bottom edge of the right hand suspension arm (#53) about 2" forward of the rear retainer spring hole. Apparently, this friction causes excessive heat the belt and the belt eventually shreds, By visually looking underneath the R/H side of the chassis and watching the raising and lowering of the mower deck with the lowering arm, it appears to me that the belt only touches and rubs the suspension arm when the deck is fully raised. There seems to be about 1/8" clearance between the belt and the suspension arm, when the deck is fully lowered. Like I mentioned, these after market pulleys I installed are about 1/8" taller than the OEM pulleys. It almost appears to me that the deck may be raising up a little too far when fully raised and thus the deck sets too high when locked into position. Could this possibly be what's causing the belt to come in contact with the lowerer edge of the suspension arm?. If that's the case, then my only thought would be that possibly the lift link nuts (#32 on the diagram) need to be ajusted downward on both the Right and Left deck lift links so that the deck sets lower? (#11 and #12). It seems like if the deck did sit a bit lower when fully raised, it would prevent the belt from touching the arm. Although, I can't explain why the belt shreds after about 30 minutes of normal use when the deck is fully lowered and the blades are spinning. Again, when the deck is lowered, and the blades not spinning, it looks like there is sufficient clearance and no rubbing of the belt.... Basically, I had no problems with shredding belts with the OEM spindles, so I'm wondering if my best approach would be to replace these after market spindles with OEM ones? Would that be a viable solution? Thanks for all your help.

 

[bertsmobile1]

OK,
For starters your spindle 285-108 are Stens item and I have fitted hundreds of the with no problems so we can count that out.
When belts wear they get thinner ( they do not stretch ) between the V sides and your problem could be nothing more than the deck being adjusted too high which the previous belt being worn could accomodate.
I gather that you did not get an owners manual with it.
If not the download one from Husqvarna using the model number from the ID tag.
The deck lever # 7 on your mower has 2 positions.
Towards you for transport and forward for mowing and I feel you might be trying to mow with it in the transport position.
You adjust the cutting height using the knob #29 and on these models it is just a bolt so it is possible to adjust the deck too high.
Similar models had a cam so you rotated through 6 to 10 heights then back to 1 again .
Also take careful note of what Star-Tech has been telling you about the tensioning pulleys or more over their arms.
I am forever replacing them due to wear allowing the arm to swing vertically.
A few thou of wear on the arm is enough to lift the belt far enough to foul on the lifting arms.

 

[StarTech]

What I am referring is items 42, 97, and 126. (Deck reference) On most mowers item 97 is completely worn away, Item 42 wear into a wedge shape, and item 126 wear on both side plus the mounting hole also wears egg shape. All this allows item 126 both tilt and to have excess vertical movement (Flop). It this tilting that causes the idler pulley drop the front entry point allowing the belt to run excessively on the up lip of the pulley. This lip does have a sharp edge and if the belt has to ride up on it, it can start cutting the belt's fabric cover. Especially under the tension that this belt is under.

As Bert said it takes a few thousandths of wear at the pivot to have an inch or more of flop and have several degrees of excessive tilt.