How quick can....

[MAD MARK 74]

Can 312-8 42" RD spindle bearings go bad? I started mowing the lawn no issues. Half hour inmowing the deck started vibrating really bad and it sounds like the left side spindle. I haven't check for play. I continued to mow the rest of grass (2 hours) at 50℅ throttle which quieted the vibration. 

 

I was able to from the seat at full throttle look down at the spindles and seeing both the left and right vibrating enough to throw them out of whack. The grease zerk wast holding steady. 

[cleat 4,936]

I had a deck do that but I hit a rock.

 

Could not really see anything wrong with the blades but I put on a new set and the vibration went away.

 

 

[Racinbob 10,256]

You should have stopped mowing. Hopefully you didn't cause more damage. It sounds like a bearing failed and that happens.

[MAD MARK 74]

I took the deck off and didn't see any play. I did notice the blades were worn in spots. I didnt hit anything at the time it started vibration. Was so loud my wife came out to tell me she could hear it inside with the TV and Ac on. 

[slammer302 2,154]

May check the belt and make sure that it does not have chunks missing on the V part of the belt. Happened to me a few weeks ago made the deck start shaking badly. When the spot with the chunks missing went across the idler pulley it would make it move in and out causing the vibration.

Edited August 26, 2016 by slammer302

[MAD MARK 74]

Thanks for bringing that up. The first time I  checked the deck, it did have spots missing on the V so I changed to a new one to eliminate that. So with new belt it still did it. I know the nylon washers on the deck are gone, but this is the first time this has happened.

[slammer302 2,154]

I would remove the belt and spin each spindle and see what you find out.

[MAD MARK 74]

They all spun freely when I did it the first time. I'm going to take it off again tomorrow and double check. The deck is old and has some welded spots. I'll have to see if any of them popped or cracked and might need more. 

[Ed Kennell 35,602]

Did you check the mule drive bearings?

[953 nut 51,497]

I have an old deck that has had a few weld repairs done over the years around the spindle mounting areas. The metal cracks where the die bent the recess in the metal around the spindle, causes a little vibration at first and gets worse with time.

[pfrederi 17,125]

I chuck a socket wrench in to my drill and spin the spindles with that.  Gets you closer to actual speed of use to see if you hear/feel anything wrong

[MAD MARK 74]

On ‎8‎/‎28‎/‎2016 at 9:21 AM, pfrederi said:

I chuck a socket wrench in to my drill and spin the spindles with that.  Gets you closer to actual speed of use to see if you hear/feel anything wrong

That's a good idea wish I would have seen this earlier.

 

I checked everything and all spindles and bearings are tight. I even took the idler bar off thinking I didn't have any washers left and they look brand new. I did see a small crack in the deck in front of the front spindle. I guess I am going to chalk the noise up to this.

[woodchuckfarmer 333]

Better get that welded up , or it will just get worse.

[MAD MARK 74]

I welded the deck up. It was cracked more severely than I thought once I got the old paint off and could see all the stress fractures. I dont think this was the issue.

 

I watched closely as I ran the mower at full speed and it seemed as though the idler bracket was causing the vibration. The loud noise must be accounted for in the bracket vibrating off the deck at near full throttle. I shimmed it up and mowed the grass and it seemed normal, maybe slightly louder than normal. Not sure why this would start vibrating all of a sudden. All the washers are fine.

 

I bought new blades today and am going to throw them on next time I mow. I am wondering how far off balance my old blades are. New blades Sten 106635. 14.5" long.