Blades Collide on 62D Mower Deck

[kb2520]

I have a 2011 JD 2520 with a 62D Mid Mount Mower. In preparing for mowing season, I pulled the blades off the mower, sharpened them, and reinstalled. This I've done at least twice per season since 2011 without issue. Today though, I complete the process of installing the deck on the tractor. With the deck raised and medium RPM, I engaged the PTO as a test. There was a terrible thunk, so I quickly switched off the PTO and shut down the machine. Upon inspection, two of the blades slapped each other as they passed. There was evidence of this in the metal. As I rotated the blades by hand, sure enough they hit each other.

Have I just gotten lucky with the alignment all these years? From the output end, does the first blade need to be positioned North and South, second blade [middle] East and West and the third blade North and South? I honestly do not know if this makes a difference or if I've done something else incorrectly. Sorry for the dunce question, but I could use some input. Thank you!

 

[Deere Dude]

My guess would be that one blade wasn't centered on the spindle which would offset one maybe an 1/8" or so.

I never heard of tractors having timed blades. Little garden tractor types but they have special belts also.

 

[Industrial Toys]

I assume there are three. Are they all the same length? I can't for the life of me believe there is a mower where the blades are synced. IF they were, the pulleys would have to have teeth to accommodate a timing belt.

 

[beenthere]

Agree with wrong mounting of blades. Once mounted correctly, they won't hit each other..

 

[KennyG]

I wonder if you have two blades mounted wrong (not over the spindle shoulder). On my 62D I don't think one mounted wrong would cause a hit. Upside down won't make a difference in clearance. Take them off and start over and you should be fine.

 

[bigtiller]

Maybe you didn't get the blades fully seated on the spindle before putting the nut on. It should be a close fit with no slop, and with no question about north/south and east/west orientation.

 

[ovrszd]

Yep, I'm with most others here. You didn't get them properly seated on the shafts. This should be evident by the fact that the blades aren't tightened up against the spool, bit of a gap on top of the blades??

Funny story bout something like this. Many years ago I was running the road grader going by the house of an elderly couple whom I knew very well. The man was on his JD mowing. The wife was standing in the driveway watching. His deck was doing a HORRIBLE job of mowing. When Lois saw me she started waving for me to stop. I got out and as I approached her she said "can you look at our mower and see what's wrong. Bill just sharpened the blades and it isn't working well at all." I said sure. Bill saw me and stopped. A bit embarrassed he said "I don't know what's the matter with this thing." I said let me take a look. I laid down on the ground and looked under the deck thru the discharge chute. Sure enough. The blades were on upside down. As politely as I could I explained my findings to Bill. He really got red faced then. I said pull in the garage and I'll help you swap them. I did it with the deck still on the tractor. He had removed the deck and turned it upside down when he removed/reinstalled them. Laying upside down he had installed them like they would go had the deck been right side up. By the time I got done we were all laughing about it and having a good visit. Couple weeks later I went in my shop to find a case of my favorite Beer sitting inside the door.

 

[Aquamoose]

By chance, were these “replacement” longer blades that you just happened to be lucky that they were synced to not hit each other up until now?

 

[ovrszd]

By chance, were these “replacement” longer blades that you just happened to be lucky that they were synced to not hit each other up until now?

As someone else mentioned, only way to stay "in synch" would be notched belt and pulleys. By design the blades are "creeping" all the time.

 

[Industrial Toys]

I have a mower currently and had another that had different length blades on the center deck. Albeit larger commercial multi wing mowers. Almost any blade I have seen sits very tight on the bolt, to the point of being difficult and annoying to remove. So, I can't see the off-center thing.

An upside down blade should not be any longer at either edge.