Flail Mower My Flail Mower- what do I need for a driveshaft?

[Flatheadyoungin]

Well, I got the gearbox on my Alamo 88" back together. This is the one I picked up off of Craigslist and it need a new thrust nut for the pinion gear.

Anyway, it didn't come with a driveshaft. I just noticed that the shaft coming out of the Alamo's gearbox is splined (like the PTO on the tractor). I thought it was smooth like a bush hog and used a soft bolt for a shear key.

So do I just need the driveshaft? It kind of scares me that there isn't something made to slip in between the tractor PTO and the mower. Or, in a bad situation, the belt would slip? I just want to protect my tractor.

About how much do the driveshafts run at TSC or other?

 

[scuvnut]

As you have found, the PTO shafts can vary between implements. I have a load of implements and most of mine have splined ends.

Be sure to count the splines - 6 is pretty common, but be sure to check. Also, check the diameter as I've had ones that vary in this department as well.

Cost will partially depend on how long the PTO needs to be - you can by a larger one and then cut it or get one that will work without any cutting.

In general, I've picked them up on ebay for $50 - $75 and purchased them new at my New Holland dealer (when in a time crunch) for $125 - $165.

Here is one on ebay that has dimensions of 28" closed, 36" open 1 3/8 6 spline on both ends. Ebay item number: 120262400293. But remember, count your splines, check your diameter and check the distance you need.

 

[DuaneW]

Just sold one of those last fall in EXCELLENT working shape, with a NEW slip clutch assembly. Would use it on the 1650 Oliver and could slip the clutch without slipping the drive belt. When I bought it the drive belt was cracked better than 1/2 way through, bought a new belt ($70+) to have when it broke. Mowed over 250 acres with it and NEVER did replace the belt. I spent over $300 (believe it was either 380 or 480, cant remember) for the correct slip clitch/ new pto shaft, from alamo. Brother thought I was nuts.

Ok, now to the point. The Oliver is rated low at 66 Hp, and could slip the clutch, but would just start making smoke when the clutch would break loose. I doubt that you could slip that clutch on a 50 hp tractor. To me the clutch was there to protect the MOWER gear box, If you dont have enough tractor to slip the clutch, you probably DONT need the clutch, save your money. If your using it on a higher HP machine, you might save yourself some money in the long run by getting the clutch for it. Oh, mine was the SHD88 Alamo and I wish I had kept the darned thing now.

DuaneW.

EDIT: just re-read your post, the flail mower will not 'hard' strike objects like a rotary cutter will/can, the knives will swing away from or bounce off of hard objects. What it will do is warp itself in grass if you dont keep the RPM's up.

 

[IslandTractor]

I don't think you'd need a slip clutch for a flail mower. The belts will provide some shock protection and the flails themselves are not likely to snag or jam.

 

[greg_g]

To me the clutch was there to protect the MOWER gear box,

I agree that a slip clutch is likely overkill on a belt-driven flail mower.

But I'm wondering if perhaps that slip clutch of yours simply didn't come with operating instructions. Mine (a Eurocardan) included information on adjusting the clutch spring tension to make the slip point consistent with your PTO horsepower rating.

//greg//

 

[DuaneW]

It did have instructions, on both replacing the clutch plates AND adjusting the springs tension on the clutch. There was no consideration for the tractor HP, just setup per the mower it was attatched to. If operating consistantly at near max capacity, the gear box would get hot, rest of the time it would be warm, but not hot to the touch. I do agree, the belt drive and the automatic tensionor should absorb most all shock, but I would not count on it slipping w/only a 50hp tractor on it. Spend the extra and get the kevlar belt, will be cheaper in the long run.

DuaneW.

 

[Rara Avis]

Well, I got the gearbox on my Alamo 88" back together. This is the one I picked up off of Craigslist and it need a new thrust nut for the pinion gear.

Anyway, it didn't come with a driveshaft. I just noticed that the shaft coming out of the Alamo's gearbox is splined (like the PTO on the tractor). I thought it was smooth like a bush hog and used a soft bolt for a shear key.

So do I just need the driveshaft? It kind of scares me that there isn't something made to slip in between the tractor PTO and the mower. Or, in a bad situation, the belt would slip? I just want to protect my tractor.

About how much do the driveshafts run at TSC or other?

Check with either of these outfits...
PTO Shaft
PTO Shaft