Mowing Finish mower used for cutting weeds?

[woodlandfarms]

Peter, if it was anyone else but you I would say you are full of hooey and you need to check again.... I have to say you learn something new every day...

I am jealous of your mower as I thought your 72" would be of the same design as my 90"... I have 3 mower heads all belt driven except for the center which is direct drive.

All 3 have zerks...

 

[J_J]

The 2007 72" brush cutter is a direct drive with a hydraulic motor. It has a single shaft, two blades, no belts. And, yes Virginia, you do want to engage the PTO with the engine idling.

There are zerks on the wheels, and the attachment plate, but not on the mower.

I didn't mean to concern those of you who have other designs.

All the best,

Peter

Peter, Are you absolutely sure that the mower spindle has no bearing? If you were to take the hydraulic motor off, would the blade assembly drop out the bottom. You have got to have a coupler between the hydraulic motor, and the spindle, unless it is a one unit assembly like the stump grinder, which has a hub mounted directly on the shaft.

I have written several articles on bearings. That greased for life quote, only means the life of the bearing before it melts down. The only sure way to test a bearing is to spin it and listen, and try and move the shaft sideways .

There have been post about re-greasing sealed bearings by puncturing the rubber seal and injecting grease. That is stretching it a bit much for economy sake. Over greasing is also a cause of bearing failure. You can find this quote many times on the Internet.

To those of you that pump a lot of grease into the bearing housings, it is probably being pushed out past the bearings and slung around the bottom of the mower deck.

 

[ponytug]

Folks,

Here's my story, and I'm sticking to it...
I remember being at the factory and being told that "the mower needs high speed grease". After I ordered the tractor, I double checked with Terry, who confirmed that "the mower" need the high speed grease. I duly went out and bought high speed bearing grease.

After I received the tractor, I went to mow, and thought I would grease it before I went out. (You know, good general preventative maintenance.)
Grease Q/A plate attachment---Check
Grease zerks on wheel axles---Check.
Grease zerks on front wheel spindles---Check.
Grease high speed coupler on mower--- No zerk, no coupler. Huh?

A short call to Power trac later, confirmed that the finish mower has spindle bearings, but the current 72" brush cutter has no coupler, and no need to grease a bearing with high speed grease. My recollection is that Terry said something about older designs on the brush cutters having a coupler that needed to be greased. Terry apologized saying he thought that I had the finish mower, rather than the brush cutter.

I just walked out to check. The hydraulic motor is bolted to the upper deck. The hydraulic hoses are at deck level, i.e. there is no space for a coupler on the upper side of the deck. The hub is below is held on by a cotter pin fastened nut. If there is a zerk, it would have to be greased by removing the hub that the brush cutter blades are installed on. i.e. removing the cotter pin, the nut on the spindle and dropping the entire hub and blade assembly, and then greasing it. Given that degree of dificulty, I would opine that this design brush cutter has no external bearings- besides the entire hub is about 2.5" thick.

Personally, I wish the brush cutter did have a coupler to reduce the impact shock when it hits something a little too solid, but this is definitely simpler. Time will tell how robust the design is. I can say that it is a pleasure to use it. 72" is a lot of space, and you can chop up 4" saplings, not to mention dimension lumber. Just be careful no one is in the general vicinity when you mow. I mow with my chainsaw facemask and hard hat/ear protectors because I have had chunks come ricocheting back towards me. (99% goes elsewhere, but 1% is still 1%.)

JJ. I've read your many postings on bearings and greasing, and we are on the same page about greasing and things like sealed for life bearings.

Of course, I now have a grease gun loaded up with high speed grease and almost no where to put it. I'll use a couple of squirts for the truck, but not too many since I don't routinely submerged it in water.

All the best,

Peter

 

[J_J]

Peter, After looking at a picture of the new brush hog, I have to agree that the blade hub is probably a one piece unit. That does seem like a big load that the bearings in the hydraulic motor has to endure.

 

[cqaigy2]

That's what mine looks like also. I too wish it had a rubber coupling between the blade and motor to but I can see why it's much simpler design and i would assume less expensive to make.

 

[ponytug]

That's the unit.

On the bright side, the bearings have fresh oil coming over them, and there are ways to design oil bearings to be shock absorbing. (and no, I haven't tried to match the motor to a manufacturer and series. It has a 2D Power Trac barcode on it, rather than a manufacturer.)

All the best,

Peter

Peter, After looking at a picture of the new brush hog, I have to agree that the blade hub is probably a one piece unit. That does seem like a big load that the bearings in the hydraulic motor has to endure.