Help with new Gator Blades on 54D deck - Blade Edges Touching

A good 'ol side by side comparison is in order I think.

dieselshadow said:

A good 'ol side by side comparison is in order I think.

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I'll take it out tomorrow and remove the blades for some photos. :thumbup1gif:

56FordGuy said:

Is the hole in the center of the blade the same size? If it's a bit too large, you could center them up when you put them on and the centrifugal force could pull them out of whack.

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The holes seemed to be correct. There was not any play in the hole when it was mounted on the spindle. While I'm thinking about, I did make sure they were balanced before mounting them. I used "nail-in-the-wall" method. :thumbup1gif:

UPDATE: I tooled around with both sets of blades today and grabbed some photos because who doesn't like photos? :unknown:

As part of my experimenting, I moved the Gator blades around to different spindles to see if that would help. I also rechecked the balance of the blades. The blades are balanced perfectly but moving them around on the spindles did not help.

It does seem that the mounting hole is ever so slightly larger on the Gator Blades (396-719) than on the stock Deere blades (M143520). In the first photo you can see the mount holes side by side (stock on the right, Gator on the left). You can't really tell from the photo but after I pulled the mounting bolts I could feel a little more play in the Gator blades than on the stock blades:



In the next photo you can see both blades in their entirety side by side, this time Gator on right and stock on left. Their measured lengths are identical.



Next, you can see just how close the blades get from moving them by hand. You can also see the tell-tale signs of where the blades have met when running at low RPM (~800RPM based on my LCD display on the instrument cluster) NOTE: The stock blades are also pretty close on the left and center blades but I've never heard them hit each other and there are no wear marks on either stock blade.:



And lastly, you can see what the center and left blades look like when mounted up:



I am afraid that 56FordGuy may have hit the nail on the head and the problem is going to be the center hole is allowing too much play and at even low speed the centrifugal force is pulling the blades enough so that they "kiss" their edges.

The problem is, these are the blades recommended as the replacement blades for the M143520 OEM blades. I've got a technical support email in to the Oregon folks to see if they have a solution. In my research, I've found additional information and instead of retyping it, I'll just post what I emailed to the Oregon folks:

I recently purchased a set of three Oregon Gator 396-719 blades from a retailer on Amazon.com. I purchased model number 396-719 after using the lawn mower blade selector guide at oreganchain.com and entering in the model number for the Deere 54D OEM blades (M143520). I received the blades and mounted them per my owners manual. After engaging the PTO, the blades will make contact slightly on the middle and left blade. There are some scuffs on the very edge of the blade. The deck is brand new, and I’ve only used the OEM blades twice to mow my lawn. The OEM blades do not make contact. I noted that the blades I received from the Amazon.com retailer have Oregon 396-719 on the product decal but they also mention that the blades are a replacement for Stens model 330-489. According to Stens, this model blade has a 13/16” center hole but the blade is 19” long. (http://www.stens.com/Portal.aspx?CN...GCONTENTID=DBC825CBB3E6&RND=34286135159738345). My Deere M143520 blades are spec’d with a 13/16” hole but measures at 18 7/8” long. I’ve also noted that the Deere blade M143520 seems to be the OEM blade for several different 54” mower decks. Is it possible that the tolerances for the Deere 54D are too close for the Oregon 396-719 to work effectively? I’m just curious if I really have the correct blades for my mower deck.

So while I'm waiting on feedback from Oregon, have any of my fellow 54D mower owners tried the Gator blades and had success?

Looking at the blade photos again, it looks like the Gator blades may be just a hair wider than the stock blades. If they are, that would mean the very tip of the cutting edge sticks out just a hair more than stock, and in the photos it looks like that is where the blades are hitting. If you wanted to get technical about it, I'd take a measurement from the center mounting hole diagonally out to the tip of the cutting edge and compare those measurements between the Deere blade and the Gator blade.

Andy B.

andy b. said:

Looking at the blade photos again, it looks like the Gator blades may be just a hair wider than the stock blades. If they are, that would mean the very tip of the cutting edge sticks out just a hair more than stock, and in the photos it looks like that is where the blades are hitting. If you wanted to get technical about it, I'd take a measurement from the center mounting hole diagonally out to the tip of the cutting edge and compare those measurements between the Deere blade and the Gator blade.

Andy B.

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You are correct Andy. The stock M143520 blades are 2.70 inches wide and the Gator Blades (396-719) are 3.00 inches wide. I'm still curious as to why these are listed as the correct blades for the 54D. i'm going to give the Oregon people time to respond with their take on the blades. Otherwise, I may just get to try out my new Bosch angle grinder. :good2:

GADeereHunter said:

i'm going to give the Oregon people time to respond with their take on the blades. Otherwise, I may just get to try out my new Bosch angle grinder. :good2:

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Good plan. There is a chance that Oregon isn't aware of the issue, so letting them know is the right first step for sure. They might have a solution, if this has happened before. If not, then I like the grinder and balance method.

UPDATE - Firing up the grinder

Well, I have been conversing back and forth with the folks at Oregon for a couple of days now. At this point, they do not have a solution and either cannot or do not want to share whether any other customers have had similiar experiences. I will say that the person I have been chatting with has been very eager to help and has responded to my emails quickly. Here is what I have gleaned from my conversations with Oregon:

My blades were manufactured in "mid 2011" based on the date code "PS" stamped into my blades. According to Oregon's records there have been no manufacturing defects reported for this particular batch of blades. They have sold blade model "396-719" as the replacement for OEM "M143520" for over 4 years. They have sold over 12,000 blades with 4,000 of those being sold this year alone! The "396-719" blades are manufactured to be 18 29/32" in length measured diagonally, just 1/32" over the 18 7/8" specified for the "M143520" blades. The 3" width of the "396-719" (as opposed to the 2.7" width of the "M143520") should not make a difference because the blade is cut on the corners with a radius.

The Oregon people are going to check into this situation some more and will let me know if they find anything. So, unless someone comes forward and says "but Brad, I've installed the Oregon "396-719" blades on my 54D AutoConnect MMM and have had no problems" then I am going to take the advice of several here and grind at least one of these puppies down and rebalance it.

RichBaxter said:

Was just wondering if GADeereHunter ever heard anything further from Oregon on this issue?

Rich

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Hi Rich,

No, I never received any more information from Oregon. I've never ground down the blade edges either. I'm still using the original blades but still own the Oregon blades. I have not needed to replace the original blades yet (I only have 25 hours on the clock) but when I do, I'll reattempt the Oregon blades again.

GADeereHunter said:

Hi Rich,

No, I never received any more information from Oregon. I've never ground down the blade edges either. I'm still using the original blades but still own the Oregon blades. I have not needed to replace the original blades yet (I only have 25 hours on the clock) but when I do, I'll reattempt the Oregon blades again.

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Thanks for the update. I am thinking of getting a set of the Oregon blades for mine.

Rich

GADeereHunter,

I am not an expert when it comes to mower decks, but I have worked on many, replacing belts and blades. Whenever I replaced a belt I always tried to make sure that the blades were close to 90 degree angles to each other. That way they would not hit. Some blades overlap 3" or so. If they were in the position that your are in I would bet that most blades would touch. Here is how I align my blades. Sorry for not having my mower deck off and in front of me.

If they are aligned like this second picture they should in fact contact one another.

So if it were me, I would take the belt off and rotate the blades to where they are at 90 degrees to one another. Then I would put the belt back on. Just make sure that while replacing the belt you don't accidentally rotate the blades again. Now, I do not know if blade position has an effect on mulching ability or air flow. I just know that they won't hit each other. My two cents.


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