2020 XT1-LT50 deck alignment

[ukrkoz]

Ok, my pretty much brand new CC tossed a belt yesterday for the 2nd time. Belt cam off with a big gush in it. I am in process of replacing it but, here's my dilemma.
1. why would a new mower toss belt twice in a row? Well, 1st time, I'll grant it, branch gut into pulley somehow and tossed it. But, belt had NO damage when I reinstalled it.
2. Here's main question. I re read deck alignment instructions twice. Wisely, it speaks in terms of distance to the ground between front and rear of the chute side blade.(speaking of deck would have been too easy, I guess) Says that front "should be 10mm less than rear". Whichever way I see it, it means deck is tilted down in the front, aye, mates?
Well, that poses a problem as, for some reason, PTO pulley is much higher up than deck and belt runs down at the angle to it. What, clearly, may cause it slippage off that pulley. Makes sense to have Front higher, so pulleys match belt direction angle. Just my simple mechanical mind.
That said, what do I know, but, considering darn belt is like a lot, I don't really want to mess with this every few mows. Especially, if it starts tearing them belts and no one has them in stock. Spring time, ha ha, when grass grows on yest.

3. What exactly is mowing height for that deck? Deck height lever has notches from 1 to 4 and little cutting logo right next to 4. At 4, deck lower edge is at 3 inches off the ground. What, I am presuming, puts blade edge at almost 4 inches. Too high a cut to my taste but, deck that high aligns pulleys with PTO pulley better, for more straight belt run. Thoughts?

 

[bertsmobile1]

You can heel the deck ( back lower than the front ) and it will give a cleaner cut.
However in long grass it will overwhelm the deck .
Once a deck belt gets thrown usually it is damaged internally so it fails completely in a short time

The blades are what does the cutting so you measure the cut by the position of the blade tips.

The numbrs on the deck height mean absolutely nothing because different types of grass will get cut at different height on the same setting.
It all depends upon the shape of the grass blades and the air flow under the deck & the amount you are cutting off the top.
thus it is a case of I like my lawn cut at the No 3 position so I cut there.
Some mower makers tried to get this through the thick stupid heads of owners by using letters but they gave up.


The reason why decks are powered by belts is because belts can handle being out of alignment, chains can not .
If yours is throwing then something is wrong with either a pulley or the deck.
Are the belt keepers still there, in the correct position and in good working order.
Occasionally a thrown belt will bend one out of position or even break it off .
Then there are owners who put them on in the wrong place
Check the pulleys for something stuck in one of the V's
Check that the tension arm is free to move & that you have put the belt on correctly.

 

[ukrkoz]

Mine has only ONE belt keeper and that is on tensioner pulley.
I just don't get it, how belt is supposed to stay well on PTO pulley, while running down at some 15 degrees.
There is no belt keeper on PTO pulley. Unless they forgot to install it, like they shipped it ot me with missing frond deck arm. Completely missing. I won't be surprised of anything else. That thing is as cheap made as it goes. Cuts well, thanks to rather powerful engine, but that's about it. They saved every penny making it. I bought bagger for it, speak of cheap plastic everywhere.

 

[bullet bob]

"I just don't get it, how belt is supposed to stay well on PTO pulley, while running down at some 15 degrees"
Something is totally missing here. That deck is not installed properly.

 

[bertsmobile1]

The belt stays on because the idler has a flange on it .
Unless you run a free floating pulley on a splined shaft, the deck & the engine can only ever be in alignment at one cutting height.
Usually this is in the middle of the range.

A keeper is only needed to prevent a SLACK belt jumping off the pulley.
Soa manual PTO needs keepers becuase the blat has to go slack to break the drive to the blades
An electric pulley does not need keepers because the belt is always tight ( ish )
He tensioning idler gets a keeper because when it is bounsing back & forth it can momentarily provide enough slack for the belt to go AWOL

DEcks come in two kings.
SIngle belt and double belts
On a single belt deck the pulleys align with the engine at the mid cut height
On a 2 belt deck, the drive pulley will align with the engin pulley at mid cut height but the blade pulleys will always be lower because of the double pulley

Wht can happen is the wrong deck end up on a mower so if a 2 belt deck goes on a single belt mower, the top ( drive pulley ) on the deck can foul on the under side of the mower
And if a single belt deck ends up on a 2 belt mower then the blade pulleys wil;l always be too low to the engine pulley.

When MTD bought Cub Cadet they adopted the Cub quick connect mounting system across the entire range.
The down isde of this is they all usr the same mounings so now can get mixed up very easily.

 

[ukrkoz]

wELL, IT'S WORKING SO FAR.
BTW, BELT PN is 954-04077A NEW 794-04077A old. 134 inch long. Yes, it's LONG belt.
A does not matter if you look it up.
Amazon has them for $45 but 2 week or so delivery.
They normally go for around $69 or so. Online order.
I got mine from Oreiley as they got it for me next day. So, if in pinch, go there. they wanted over $90 after tax for it but price matched Tractor Supply online price of $65.
Fits perfectly. Appears to be working well too.
As one of you here scared me shitless, I now mow at 3 and belt is more or less aligned with deck. Down angled maybe 8-10 degrees.
Also, I heeled deck more than they recommend. I made it horizontal, not nosed down. Figure, that also helps.