Flail mower bearings

[Skramps]

Hey guys,
I’m rebuilding a Mott 60 flail mower I picked up for $200. I’ve priced out the parts I need and it’ll run me around $650. The bearings and housings are almost $160 per side. Ive cleaned everything up as best I can. My concern is on the cuttershaft ends. One side looks good but the other side is fairly well pitted. I would really like to bring this mower back to life as I would be in for under $1000 instead of the $2k plus for a new one. This unit seems very heavily built as well and the gearbox is flawless. My question is if it’s possible to buy something like a shim or collar that would allow me seat the bearing properly if the new bearing won’t seat on the shaft as is and if anyone has used something like that.

 

[Andrew JohnMorris]

You could try something like this. Cut some thread into the remaining metal and then build up with this epoxy. Turn down until it takes the bearing

I’ve only tried once and not yet reassembled but the theory seems sound

 

[Outinstickssnafu]

Not familiar with the mower ... but guessing price of bearings it's a big shaft and a fair bit of material has worn off the end. Next step depends on skill set about. If not taking it to a engineering shop for them to rebuild the end, you can do the same carefully depending on shaft material and without a lathe even, but it's really tedious work.


However, once again I'm not familiar with the mower and someone who knows them well may know what you'll get away with. If the rod was a very high tensile steel like what we call resaflex, any ideas of welding it yourself might be sunk.

 

[Skramps]

View attachment 736101
You could try something like this. Cut some thread into the remaining metal and then build up with this epoxy. Turn down until it takes the bearing

I’ve only tried once and not yet reassembled but the theory seems sound

I just saw a video where someone fixed a spinning bearing with a similar Loctite product. I agree that it should work in theory so I’ll be ordering some and trying it.

 

[Skramps]

Not familiar with the mower ... but guessing price of bearings it's a big shaft and a fair bit of material has worn off the end. Next step depends on skill set about. If not taking it to a engineering shop for them to rebuild the end, you can do the same carefully depending on shaft material and without a lathe even, but it's really tedious work.


However, once again I'm not familiar with the mower and someone who knows them well may know what you'll get away with. If the rod was a very high tensile steel like what we call resaflex, any ideas of welding it yourself might be sunk.

I’m hoping to try an epoxy solution first to see if that will work. But good point that bringing it into a shop might be the best option and just have them deal with it. I’ll see if the epoxy works and then go from there

 

[Outinstickssnafu]

The flail mower bearings do get a hard time unless it was only cutting a light lawn. As a patch, I've yet to see epoxy of any sort work in high load situations where the shaft has been tapered off due to damage, work for any great period of time. If you do try the epoxy path, if there's room for tacking the rod sized washer on the end of the rod more or less dead center, it'll at least of all stop it pushing out to some extent.

If it wasn't as badly pitted or deformed, I'd have suggested brazing using something like a nickel bronze gear repair rod (Aust that would be comcoat N.)

 

[Skramps]

The flail mower bearings do get a hard time unless it was only cutting a light lawn. As a patch, I've yet to see epoxy of any sort work in high load situations where the shaft has been tapered off due to damage, work for any great period of time. If you do try the epoxy path, if there's room for tacking the rod sized washer on the end of the rod more or less dead center, it'll at least of all stop it pushing out to some extent.

If it wasn't as badly pitted or deformed, I'd have suggested brazing using something like a nickel bronze gear repair rod (Aust that would be comcoat N.)

That’s a fair point and that was my initial concern. Spending that much money on a repair that will possibly fail the second it’s under a load (I’m intending on light brush cutting, not lawn work). It’s just very tempting to save a few thousand. Tacking the washer is a good idea. I may yet lean towards just saving and buying a new flail

 

[Outinstickssnafu]

If you weld, migs these days make it easy, you don't want too much heat if the shaft is made from something special. Even if it means adding metal slowly, and not to any one side more than another, it's not so much welding but adding blobs of instant hard metal putty. The shaping the end back to round is the hard part and a makeshift jig to set the rod against a grinder, will help a lot to get close before manually filing ... or if you know someone with a big lathe ...

Machining shop rates vary and would depend on what they would do ... and what the going rates are in your parts. My way things get expensive quick, and had a simple threading high tensile rod both ends costing me a bit over weeks wage. I wasn't expecting to be stung, I would have preferred to put an expensive large die for much less and done it myself.

 

[Skramps]

If you weld, migs these days make it easy, you don't want too much heat if the shaft is made from something special. Even if it means adding metal slowly, and not to any one side more than another, it's not so much welding but adding blobs of instant hard metal putty. The shaping the end back to round is the hard part and a makeshift jig to set the rod against a grinder, will help a lot to get close before manually filing ... or if you know someone with a big lathe ...

Machining shop rates vary and would depend on what they would do ... and what the going rates are in your parts. My way things get expensive quick, and had a simple threading high tensile rod both ends costing me a bit over weeks wage. I wasn't expecting to be stung, I would have preferred to put an expensive large die for much less and done it myself.

Understood. I may end up doing this. Off topic but are PTO shafts interchangeable? I have a PTO shaft with a slip clutch on a tiller and this flail mower does not have one at all. I assumed they were interchangeable as long as the lengths match up but as I was shopping them online I kept seeing "xx shaft for tiller", "xx shaft for finish mower" so now I'm not sure.

 

[CADplans]

PTO shafts fall under the category of "ANYTHING GOES!!"

Besides length, the shaft can be splined, round, male, female,, on,,, and on,,,

I needed one for a RFM,, it was such an oddball, that I ended up finding it on eBay for $25 plus $10 delivery.

The pto shaft was brand new,, but, it was such an oddball,
the seller had very little of customer interest, and kept dropping the price.

I happened to luck out,,