Ford 917L flail mower vibration

[Jeepdoc78]

Hello all.
I have a 917L flail that has turned into more of a project than I had hoped. I installed all new knives and fixed a pulley issue that I thought was causing some vibration but it still vibrates more than it should.

A look underneath reveals some rebar(3 pieces, left, center and right) welded to the shaft as well as some square stock weights that look factory. When I got the flail it was missing some knives. I wonder if a previous owner welded the rebar on to balance the mower instead of buying replacement knives.

Does anyone with 917L mind looking underneath and seeing what their weights look like? I'd like a second opinion on what I've got before I start grinding off the rebar.

Thank you for your help!
Dean

 

[5030]

cut the rebar off and grind down the welds flush with the shaft. That should eliminate the issue. Obviously, the previous owner was a cheap skate.

 

[MTGreen]

Mine does not have any weights welded on and runs fine after end bearing replacement. Agree with above

 

[Rustyiron]

Without completely removing the whole center tube and placing it in some type of fixture with bearings to simply gravity balance it, how would someone (the previous owner) even begin to balance this assembly beyond wildly guessing? [This is me questioning the dude with a welder theory]
On the other hand, little hunks of rebar from the factory? Not likely either.
Good luck with your restoration and I hope you get that smoothed out.

 

[Jeepdoc78]

Thanks everyone. I'll break out the grinder this weekend and let you know how it goes. I did check the shaft with a straight edge and it appears to be true.

 

[John0829]

I think before I did a bunch of grinding to remove the "add-ons" I would remover the knives, yeah I know PIA, then spin it up to see if the in-balance was still there with the bare rotor. Just my $0.02

 

[chim]

I don't know beans about flail mowers. However:

Is that a before picture? Those knives don't look very new, and the bolts look as though they've been undisturbed for a while.

Are all knives present and accounted for? Any chance there may be anything missing? Check the pattern of those little weldments and see that it's uniform.

Assuming the rotor is hollow, and chance something inside isn't contributing?

 

[5030]

After removing the rebar (simple matter with a gas axe and minimal grinding), I'd check the end play in the bearings because continued vibration can and will eat up the bearings.