Hydro vs Manual deck height

[clueless 2,898]

Put gator blades on a JD 48"deck when they first came out, what a mess they made.

[scoob8000 29]

So a little update.   I got my leveling tool that I ordered.   What I thought was accurate with a block of wood turned out to be way off.  

 

I now have it within 1/4" lower front to back.   I had to crank the adjuster in a little more.

 

I also found my original blades, sharpened them up and put them on.    They definitely fling the grass further out the chute, but the clippings coming out the front of the deck are about the same if not a tiny bit better.  My left sock is still stained green from clippings.   The front axle, foot rests, my boots, etc all covered in clippings after 5 minutes of mowing.

 

I don't know what, but I'm convinced there is something wrong with this deck.   Some wrong parts, bent, twisted, or something.    I need to find a nice rear discharge to trade someone.  

Edited April 25, 2017 by scoob8000

[bmsgaffer 2,043]

One last thing I can think of to check is the spindles. First make sure you have the blades spaced correctly. I believe there is a thin washer that goes above them and a thick below, but it has been a while since I removed my blades so I could be wrong on that. Second, measure the spindles from the deck to where the blade rests and maybe someone here can measure the same. Maybe someone in the past replaced the spindles with ones that were too long? 

 

My thought being that maybe the blades are down a bit too low to the ground. 

 

Can you take a picture of the deck from ground level both of the front and underside (from the chute with blades showing is fine)?

 

I hope we can solve this!

[pfrederi 17,147]

measured 3 48 SD decks all slightly different vintages.  4-1/4 to 4-3/8 from deck shell to bottom of blade.  interesting never really noticed before the blade actually is slightly below the front edge of the deck shell.  in the RDs their shell is much thicker (taller) and the blade is above the leading edges of the shell.  I always mow at max height and i get grass blowing out the front enough that I carry a brush to keep the blower screen clean, but not as much as it sounds like you get.

[scoob8000 29]

bmsgaffer, I'll measure that, I've often wondered if that were part of the issue.

 

pfrederi, funny you mention that about the blades being lower than the front lip of the deck.   Mine definitely are and I always thought it was kinda odd.     I'm sure if there were no wheels on the deck and you set it on a concrete floor, the blades would touch the ground in the front.

[bmsgaffer 2,043]

Thats interesting...  I am almost certain mine are very close but were short of the deck edge... I will have to check tonight!

[ztnoo 2,298]

pfrederi,

Interesting you should mention that deck shell to bottom of blade dimension. 

 

After my massive screw up of running over a 3/4" steel form stake last week I had forgotten was in the yard marking something, and which was obstructed by high grass as that was my first mowing of the season, I had my 48" 5-1482 SD deck off my GT 14 to remove a badly bent center blade and replace the other two as a seasonal swap which needed to be done anyway.

While I had the deck turned upside down at working waist height to fit the fresh blades, I out of curiosity checked that very same spec you mentioned. All of my blades ran between 4 5/16" - 4 7/16".

I think that's surprising and refreshingly accurate considering the deck is the same age as the 1969 tractor to which it is mounted.

Not only was I checking to see the relatively height of each of the three spindle/blade units, I was primarily concerned if I had bent the center spindle or bent its mounting in the deck top skewing its operational height from one side of the blade to the other.

 

To my good fortune, I believe I did not, after finding the aforementioned dimension running as consistently as it was from one end to the other of the center spindle blade.

My second mowing yesterday afternoon with the deck remounted showed no readily apparent discrepancies in running height between the three spindle/blade units. Thank goodness and AMEN!

I too noted all the blades were running approximately 1/4" above the bottom edge of the deck shell when I had the deck bottom side up with all blades bolted to their respective spindles.

[scoob8000 29]

So I think we're finally on to something.  

 

Using my new little blade height tool I measured:

 

Left (engine cooling fan intake side) blade tip is 1/4" LOWER than the leading edge lip of the deck.

Right (discharge chute side) blade tip is 1/4" ABOVE the leading edge lip of the deck.   

Lip of the deck to floor is the same on both sides.    This makes me think my deck is either twisted or one wrong spindle.

 

Next step will be to pull the deck and measure the spindles and check the deck with a straight edge.

 

Funny with overall 1/2" of difference from side to side, there are no noticable marks in my mowing pattern.

[scoob8000 29]

So a month later I accidentally find something.      I've got a bearing going bad in my 48" so I pull it off to put the 42" back on and something catches my eye on the pulleys.

 

Looking at the parts diagram the double center pulley should have the larger side UP.  (larger pulley is for the PTO belt, smaller groove for deck belt).

 

Mine is backwards.   So I'm thinking that's causing the blades to spin way faster than they should and possibly my issue.    I've looked at that parts diagram 50 times and never noticed my deck was backwards.     Going out to flip it and see what happens.

 

Will report back.

 

[edit]  Too wet to actually mow, but did some before and after tests with my laser tach.

 

Outside spindle RPM before and after:

Before: 6083rpm

After:  4291rpm

 

Those blades were spinning nearly 1800 rpm too fast!   We'll see what happens soon as it drys up out there.

Edited May 29, 2017 by scoob8000

[bmsgaffer 2,043]

Wow! That would make a difference! Also, the center blade would have been spinning at a different speed than the outside two, probably accounting for the biggest issues you saw. 

 

Federal law mandates manufacturers design blade tip speed to be no more than 19,000 ft/min (~216mph). Your blades were spinning at 25,487 ft/min or about 290 mph! Wheel horse designed them for about 17-18k and after your switch you are running at 17,979 ft/min.

 

I would very carefully inspect the blades for stress cracks starting to form as they were not designed to go that fast... Maybe even a new set of blades as your resharpened originals have been running that way for a while. I would bet that that deck works beautifully now (save for the bad bearing!) 

Edited May 30, 2017 by bmsgaffer

[Ed Kennell 35,773]

On ‎5‎/‎29‎/‎2017 at 8:42 AM, scoob8000 said:

So a month later I accidentally find something.     

 

Looking at the parts diagram the double center pulley should have the larger side UP. 

 

This is why .     Someone could have seen this 6 weeks ago.

[scoob8000 29]

Well I don't have anything left to mow in my yard, but I mowed a small 50x50 or so section of my neighbors.    It's not as bad, but still bad enough to bother me.  Those clippings on the screen are from that small section of mowing.  The other 48" deck I can mow my entire yard and not have to clean it off until the end.

 

bmsgaffer, just curious.  How do you compute blade tip speed from RPM anyway?

 

Ed,  Here's some pics.  Probably too little too late.        Those stainless bolts are from my make shift rubber skirt I tried.   It didn't do much so I took it off.

 

On a side note, does it matter that this deck once had a power flo bagger on it?

 

 

 

 

 

Edited May 30, 2017 by scoob8000

[Ed Kennell 35,773]

Thanks for the pics Scoob.  I don't see how the bagger brackets and xtra pulley would cause any changes.   The only thing I see that looks suspicious is there appears to be an obstruction on the underside of the deck between the left spindle and the baffle.  What am I seeing there?

[elcamino/wheelhorse 9,051]

@scoob8000 It appears that the center blade is cracked on the ends. The front anti scalp wheels may be a different diameter.

[scoob8000 29]

10 hours ago, Ed Kennell said:

Thanks for the pics Scoob.  I don't see how the bagger brackets and xtra pulley would cause any changes.   The only thing I see that looks suspicious is there appears to be an obstruction on the underside of the deck between the left spindle and the baffle.  What am I seeing there?

 

No problem.  I should have posted some sooner.      I'm not seeing anything on the underside pic.   Clump of grass perhaps?   I didn't clean it before I took these.

 

9 hours ago, elcamino/wheelhorse said:

@scoob8000 It appears that the center blade is cracked on the ends. The front anti scalp wheels may be a different diameter.

 

Really good eye!  There is a crack starting on that center blade right at the "lift wing".   These are old blades I put on just for testing to see if it made any difference.    The roller is a different shape but the same diameter.

 

 

This deck cuts nicely now, just can't wrap my head around why I get so much clippings coming out from under the front of it and virtually none with my 48" deck.  

[cleat 4,984]

The 42" decks are worse.

I sold my 42" decks partly because of that.

 

60" deck does not do it at all (maybe bigger actually is better).

[Sarge 3,462]

I've got nearly the same issue - except with a 48" deck that blows more out the front than the rear ...hate to have it clogging the fan intake on the engine , not to mention throwing grass on me more than out the discharge . Need to revisit the spindle lengths again , maybe at one time they were changed and the longer ones used or something - those blades are nearly lower than the deck shell .

 

Sarge

[scoob8000 29]

6 hours ago, cleat said:

The 42" decks are worse.

I sold my 42" decks partly because of that.

 

60" deck does not do it at all (maybe bigger actually is better).

 

Maybe it's just the nature of the beast then..    It is a lot better since I've adjusted the height better and got the pulleys correct.  Hopefully I'll find another 48 SD or even a 42 RD for a good price locally then I'll sell this puppy.

 

4 hours ago, Sarge said:

I've got nearly the same issue - except with a 48" deck that blows more out the front than the rear ...hate to have it clogging the fan intake on the engine , not to mention throwing grass on me more than out the discharge . Need to revisit the spindle lengths again , maybe at one time they were changed and the longer ones used or something - those blades are nearly lower than the deck shell .

 

That's interesting.  No matter how I mow with my 48" it isn't nearly as bad.  I kind of assumed like Cleat said, it's bigger and hangs out further.    But what you explain is what I've been dealing with the 42".   My left leg and shoe gets covered in grass.  My left sock sometimes has green stains on it.   I almost need safety glasses when I'm running it and it's dry out.

 

With the blades facing front to back, the front is actually a hair lower than the lip of the deck.   Both of mine are like this.   I've often wondered if that was correct or not.

 

[pfrederi 17,147]

25 minutes ago, scoob8000 said:

 

With the blades facing front to back, the front is actually a hair lower than the lip of the deck.   Both of mine are like this.   I've often wondered if that was correct or not.

 

  I just looked looked at a 42 and 48SD and the blade is even with the edge of the deck Actually slightly below it.  The 48 does kick up enough stuff that  carry a small brush to clean the flywheel screen but nothing like your issue.

 

The 42 RD i have i haven't used in awhile but do not recall it kicking out grass.   However the blades in that are well above the leading edge of the deck 1/2" or more. 

 

Got to wonder if at some point the wrong spindles were installed in yours

 

.Also the shell of the 42RD is about 5 Inches tall the SDs are only 4-1/4

[Sarge 3,462]

The whole issue with these decks and quality of cut - or more importantly how they discharge/disperse the clippings comes down to the depth of the deck . I have considered making one shell that is extended by an inch to help gain more vacuum and better air flow - but the limiting factor is the clearance to the frame due to the way they engineered the hanger assembly of the semi-floating design . Most of our tractors and their corresponding decks are known to cut notoriously short - even with the adjuster on the deck at the highest setting - it's just how they were designed . I've often wondered if adding a strip of rubber that extends down 1" to the front would help alleviate the air flowing out from the front of the deck and blowing clippings in a direction that is not helpful . Trick would be to keep it from folding inward and possibly contacting the blades...if I get time this summer I may try this by welding studs to the front face and using some 1/4" thick rubber strips I have here - we'll see .

 

Sarge