My Mott F6 Rebuild Thread

[LD1]

I am the one who posted the Flail mower ID thread. Thanks to those of you who helped out.

http://www.tractorbynet.com/forums/attachments/200774-flail-mower-id.html

But I'd since it is several pages already, I figured I'd start a new thread with the pics and steps through the rebuild process:thumbsup:

For a refresher, here's what I started with

 

[LD1]

I dis-assembled everything and prepped for painting.

Here's a pic of the primer I shot last night.

The second pic is of the shaft and bushing I had to make to make a 6007 bearing work. Details are in the other thread on that dilema. It is NO a brass bushing. Rather it is stainless but I made it a .003 press fit so when I heated it, this is the color it turns. Once heated, it fell right into place:thumbsup:

 

[LD1]

The "Equipment Yellow" paint I shot this morning. Also, the flange for the pully side I had to make.

 

[LD1]

All finished. Assembled and tested out.

Everything works ok but I do notice a good but of vibration between 1600 and 1800 tractor RPM. No issues at Idle or at 540PTO which on my tractor is ~2500RPM. Just that one area while bringing up to speed.

Those of you with flail mowers, any ideas:confused2:

 

[leonz]

All finished. Assembled and tested out.

Everything works ok but I do notice a good but of vibration between 1600 and 1800 tractor RPM. No issues at Idle or at 540PTO which on my tractor is ~2500RPM. Just that one area while bringing up to speed.

Those of you with flail mowers, any ideas:confused2:

You have a dangerous imbalance some where;

Are all the knive pairs intact on the rotor with 2 grass slicers per hanger?




EDIT: Why is the Yoke so far away from the gearbox????????????, thats not good.

EDIT: your drive shaft does not look healthy after taking a second look with the photo enlarged.
I would take a good straight edge and palce it between the left and right arms of the flailmower
mount and spin the PTO shaft by hand.

The vibration may cease if you reposition the mounts on the furthest holes if not there already.


Candidly looking at the photo from from the right sideI think the drive line and yokes are suspect.



Are the yokes at 180 degrees to each other?, they must oppose each other.

This is sometimes usually the culprit as it should be balanced to the 2500 R.P.M.

Is the V belt tight? no more than a 1/16-1/8 of an inch of slack on the top belt?

Are ALL the grass slicer knives in place?

Are ALL the broken grass slicers removed with the corresponding opposite grass slicers removed?

Are all the broken knive hangers removed with the corresponding knive hanger rings and bolts removed?

 

[leonz]

My last two thoughts are regarding the 3 pulley support and belt tension bearings being worn and UGH!!?, the sleeve breaking loose and spining with the inner race of the bearing?

 

[LD1]

You have a dangerous imbalance some where;

Are all the knive pairs intact on the rotor with 2 grass slicers per hanger?


yes

EDIT: Why is the Yoke so far away from the gearbox????????????, thats not good.
Thats the way that PTO shaft is. The shaft on the gearbos is identical to the tractor side. With the indentations of a quick disconnect type. So that is all the farther on it can go.
EDIT: your drive shaft does not look healthy after taking a second look with the photo enlarged.
Yes the PRO shaft is not that healthy. I have a new one ordered but it wont ship out til monday. This is the one off my Bushhog and I dont have any problems with it.
I would take a good straight edge and palce it between the left and right arms of the flailmower
mount and spin the PTO shaft by hand.

The vibration may cease if you reposition the mounts on the furthest holes if not there already.
Not sure I understand you here. Could you please elaborate.

Candidly looking at the photo from from the right sideI think the drive line and yokes are suspect.



Are the yokes at 180 degrees to each other?, they must oppose each other. yes

This is sometimes usually the culprit as it should be balanced to the 2500 R.P.M.

Is the V belt tight? no more than a 1/16-1/8 of an inch of slack on the top belt? it is as tight as it can be. Spring tensioner:confused2:

Are ALL the grass slicer knives in place?yes

Are ALL the broken grass slicers removed with the corresponding opposite grass slicers removed? none are broken

Are all the broken knive hangers removed with the corresponding knive hanger rings and bolts removed?

The PTO shaft is not that healthy as mentioned. But I have NO issues at all with it on the bushhog. We'll see if the new PTO cures the problem. But I probabally wont get it until wednesday or thursday.

My last two thoughts are regarding the 3 pulley support and belt tension bearings being worn and UGH!!?, the sleeve breaking loose and spining with the inner race of the bearing?

Brand spanking new pulley with bearing. Everything there is tight. But I do notice the belt kinda "slapping" around a bit. Almost like it needs a stiffer spring. But I only notice that when it is bat at 1600-1800rpm. It doesnt do it below that RPM or above:confused2:

If you could, could you further elaborate on the mounts and such that you made mention of.

 

[leonz]

The PTO shaft is not that healthy as mentioned. But I have NO issues at all with it on the bushhog. We'll see if the new PTO cures the problem. But I probabally wont get it until wednesday or thursday.






Brand spanking new pulley with bearing. Everything there is tight. But I do notice the belt kinda "slapping" around a bit. Almost like it needs a stiffer spring. But I only notice that when it is bat at 1600-1800rpm. It doesnt do it below that RPM or above:confused2:

If you could, could you further elaborate on the mounts and such that you made mention of.

The V belt is not supposed to slap around AT ANYTIME when under tension, it must be very, very, tight with the spring.

The flail mower belts undergo a lot of shock loading when working and the spring tensioner reduces the power loss to a bare minimum. The V belts should be replaced annually as the rubber degrades from the natural ozone in the atmosphere.



There two support greased bearings and a tensioner pulley bearing(lifetime lubricated)


If the crown of the old belt is not above the pulleys give this one a funeral
and buy a new kevlar belt at a NAPA store etc.

Is the belt new or was it on the mower when you purchased it?

If it was on the mower most likely the cords are failing as the springs only suffer from massive failure/violent breakage-like garage door spring breaking.


The mounts I was referring to are the slotted attachment points in the mower frame; are they set so the mower is as far away from thr tractor when the mower is on the ground?

 

[LD1]

The V belt is not supposed to slap around AT ANYTIME when under tension, it must be very, very, tight with the spring.

The flail mower belts undergo a lot of shock loading when working and the spring tensioner reduces the power loss to a bare minimum. The V belts should be replaced annually as the rubber degrades from the natural ozone in the atmosphere.



There two support greased bearings and a tensioner pulley bearing(lifetime lubricated)
All these bearings are good. The cuttershaft bearing was replaced, the tensioner pulley is new, and the drive shaft bearing(4-bolt flange) was still good and tight.

If the crown of the old belt is not above the pulleys give this one a funeral
and buy a new kevlar belt at a NAPA store etc.

Is the belt new or was it on the mower when you purchased it?old belt

If it was on the mower most likely the cords are failing as the springs only suffer from massive failure/violent breakage-like garage door spring breaking.


The mounts I was referring to are the slotted attachment points in the mower frame; are they set so the mower is as far away from thr tractor when the mower is on the ground? Yes

I asked in the other thread what those slotted holes were used for. Do you know? Currently it is set up ALL the way back, with the mower as far as possible away from the tractor.

 

[leonz]

I asked in the other thread what those slotted holes were used for. Do you know? Currently it is set up ALL the way back, with the mower as far as possible away from the tractor.

About your flail mower;


The old belt has to go to the V velt graveyard or a recycling station.

The further the mower is away from the tractor the less likely the P.T.O., shaft will bend and bind when raised.

The further the mower is rearward the less likely you will (1) scalp the lawn if the mower encounters a ditch and (2)the mower will be able to cut a level lawn for you.

Be sure the top link has some slack when mowing
(when the mower is fully lowered to prevent scalping too.(this occurs because the mower cannot travel forward slightly to follow the contour(if there is no slack as the rear roller follows the ground at all times when mowing) Once you start shredding you will want to use the Mott for everything; all the trash and brush will be knocked down and the invasives will be dead or nearly dead.

Once you start on the brush you can mow at a creaper gear speed and all that will be left for you is sod as all the trash will be shredded to very tiny pieces that will dissolve and compost quickly. All four rows of knives will reduce the brush to nothing when you walk back over it(the other thing you will be able to do in a heartbeat is re-shred the same material with half the effort or less simply by reversing or over lapping and in a few days it wil be gone.

You will be able to buy dethatching blades for your Mott mower as well and remove all the thatch and reseed and add limestone and gypsum for your soil and turn the brush land into nice grass sod if desired.


enjoy;

One more convert for the flailmower nation. so many more to go:thumbsup: