ZT52HD DECK VIBRATION FIX

[coder]

Sure.

Making a case for this upgrade. It is a worthy upgrade on multiple levels.
The solution (complete with the filter minder) takes the guesswork out of air filter changes,
and contributes to the longevity of the engine. (Mainly by cutting down on airborn particles entering the intake, by virtue of
its superior filtering efficiency) It also decreases the number of air filter changes needed.

Next, somebody is going to ask, if it is such a great option, why Kawi does not just slap this air box on their FR or FS engines to begin with?
Or why do they not provide this as an upgrade? I good question, IMO. They should. Maybe they will, at one point.

I guess they want to give us some incentive to spend the $$$ on Pro model ZT-s with one of their "pro" engines.
The "differentiating" between the 3 levels of air filters available is entirely marketing driven.

For example, the entry level filter is just the flimsy, tear-prone paper filter. If you look at the engine service manual,
one of the recommended steps for filter inspection is to check for tears in the paper media. Great..

The next option is the same thing, but with a foam prefilter added. (How did they make a case for not having a $1 foam pre-filter?)
And the best option is a cylindrical filter, except they do not seem to want to provide that for "entry level" engines.

 

[cpurvis]

Adding a good air filter to the entire engine lineup would add cost. Unless ALL manufacturers did it, know-nothing-except-price customers would flock to the ones who can sell for less by putting a cheap filter system on their engines.

P.S. We're in the wrong thread. This one is about the Gravely 52" deck vibration issue.

 

[coder]

Yes. sorry about that, got carried away... I promise not to post about ai filters here.

 

[bertsmobile1]

It is all about the ticket price
There is 5/8 SFA difference between the FR & FS engines and it probably cost Kawasaki more to make the 2 variations than the difference in the wholesale price.
However Joe Public wants CHEAPER even if they are buying the top shelf engine on offer for a particular mower they still want it to be CHEAPER .
Thus the FR, FS & FX variation of exactly the same engine .
OTOH commercial customers can claim the mowers purchase price as a tax deduction of some sort so purchase price is not a problem for them in their heads .
Longevity & reduced maintanance time / cost is tops in their minds and the canister , fit & forget till it tells you to replace it is just the thing they want .

 

[coder]

OK.. back to the original topic: deck vibration.

On my 2021 model Ariens Apex 52, the PTO belt tensioner pulley arm has 2 mounting position for tensioning pulley, (and the belt safety "finger")
I can move these to the mounting holes to the left of the current factory position, and this will effectively increase the tension of the PTO belt slightly.
I think I like this solution more than I like the solution Ariens support recommended: "Buy a shorter aftermarket belt".
When I do this I will post pictures.

Just got my handy belt tension measuring tool, will measure the tension "before" and "after".

Now I just need to figure out how I can get at the blades, so I can take them down and balance them.

I have a couple of rapid racing jacks, I was thinking of just jacking up the front, putting one of the jacks in the middle , under the balancing weights.
Should be strong enough there.

PS. Changed my motor oil @6 hours to Redline 15W-50, and the original Kawi filter to Fram UG4967. Seems to run noticeably quieter.
My idle used to have a bit of "syncopation" to it, it is now evened out.

 

[coder]

Following up on the deck vibration topic.

I measured the current PTO belt tension. The common sense guideline suggests 1/64 inch deflection for every inch of segment length using a deflecting force of 10 lbs.
The segment in question is 72 inches. According to the generic principle, deflection should be 1 and 1/8" . I measure 1 5/8". So this belt does not appear to have enough tension.
And, as I observed before, it did did not look to me it had enough tension to begin with, with the way it is dancing around like crazy.

The tensioning arm has 2 possible positions where the pulley can be mounted. It came from the factory with the pulley mounted in the lower tension position.
Or perhaps it was part of the dealer's de-crating and assembly. I am optimistic that remounting the pulley will take care of the vibration, easy enough to change.

What disappoints is that Gravely /Ariens tech support did not know what the tension should be on this belt, nor it is in the service manual
and the support people were unaware that the tensioning pulley had 2 possible mounting position.

I am trying to figure out how to get at the blades without dismounting the deck, so I can take them off and balance them. I have a pair of ramps for working under my cars, maybe
that is good enough, given an impact gun. I see some Zt mower lifts on Amazon and HF, with a crossbar and "baskets" on each end of the crossbar
for the front wheels, it that what everybody uses?

 

[coder]

I did the "reposition tensioning pulley to increase belt tension".

Repositioning the tensioning pulley made the deck vibrate less overall, esp at full RPM. Instead of the belt section whipping between the pto and the center pulley, now the tensioning arm is bouncing excessively. Ariens tech support suggested to put on a belt an inch shorter, "unfortunately they do not have one in stock" .
They seem to have a 127", 5/8 belt : 7239300 Ariens Gravely PTO Mower Belt 5/8" x 127" B124 5L127

They said "you may want to find an aftermarket belt" .

I asked them to ship one to me, and state in a letter that I am allowed to put on the 127 belt s per their recommendation.
as a fix for a warranty issue. I want to avoid voiding my warranty because of performing an "unauthorized modification".
Talked to my dealer. Not surprisingly, not very useful. They want $40 to pick up the mower so the can look at it.

 

[MParr]

@coder
I use a floor jack to access the blades. Use jack stands for safety.
I have a DeWalt cordless impact to remove and install the blade bolts.

 

[NealS]

We purchased a ZT HD 52 in 2017. We have about 200 hours on it. We have been following the noisy deck problem for some time. We did add a idler pulley for the long side of the belt that seemed to be slapping so bad. Also pressed an indention into the pulley cover, to create clearance, which was rubbing on a bolt, or maybe stud. We have thought that most of the harmonics had been cured. The other day we experienced something that made this flash back into my mind. Have no idea if it could be part of the problem.
We had made a lift, to pick up the mower with the front end loader on our tractor, so we could stand upright to work on the underside of the deck. We were using a pressure washer to clean the deck underside. While doing so, we noticed, when we hit the underside of the deck, just right, it would give off a rattle sound. I think it must be where curved metal behind the blades (grass deflectors, one each blade) lays against the rear side of the deck housing, causing a viberation between the two pieces.
We wonder if it might be possible for this to be an overlooked viberation noise, some of us are hearing?

 

[coder]

It looks like this mower deck used to have a severe harmonic vibration and I think they fixed this to some degree by incorporating the "anti vibration kit" they were giving people to try out. I am thinking this, because the original tensioning arm used to be black, and now it is silver, just like in the kit. I think, the problem I am describing is not quite as bad. It is just excessive belt slapping now.
The current manufacture Ariens/gravely does not have any more problem with harmonic noise or the belt rubbing on the guard finger.
I got my 1" shorter V belt (Scag 127" x 5/8" ). Put it on today, did not seem to make much difference. I have to try putting the tensioner pulley back in its original position on the tensioner arm.