Rotary Cutter Used brush hog - what to do before hooking up

[RickB]

Except for those folks that have a torque wrench with different settings, who have checked the torque of those settings, and have a regulator to keep the air pressure a constant.

How many of these folks do you know?

 

[RoyJackson]

Grease the Zerks on the PTO shaft U-joints.

Make sure the PTO shaft slides in and out easily. Grease it or use WD40 or PB Blaster to loosen it up.

Make sure the PTO shaft is plenty long enough to fit between the tractor's connection and the mower's connection. It should overlap several inches to be safe.

But also, make sure it's not too long!!
Remove the PTO drive shaft from the cutter (since there's other maintenance to do on it anyway) and rig the cutter to your 3PH
Raise your 3PH slow enough that you can determine when the tractor's PTO stubshaft and the cutter gearbox input shaft are closest. Measure that distance (I use the dimension from locking groove to locking groove).
Then lower the cutter to the ground.
Then collapse the (previously removed) driveshaft to it's shortest length and measure it...remember, you're measuring from the locking device (pin or balls) from one end to the other. This length must be shorter then the minimum dimension you measured between the tractor and implement.

Check the oil in the gearbox (as already stated). First to make sure it is full and then if is it milky at all, change the oil. Probably should do that anyway.

If you can get under it to look at the blades than make sure the blade bolts/nuts are tight. And if the stump jumper is held on with a bolt, check that too. Give them all a healthy torquing with a wrench - impact if you have one.

When starting it, do it at low RPM to diagnose any unusual vibrations or wobble.

If this is your first time using a cutter...well, they all vibrate initially (for a few seconds). Do engage your tractor's PTO at a lower RPM (1000 RPM or a bit lower) and let the cutter turn for a few seconds. You may hear a "bang" as the cutter blades pivot out...then any vibration should smooth out. Then slowly and smoothly increase the engine RPM to PTO speed.
If there's still vibration, the cutter's blades may not be balanced or one may not have pivoted out.
Again, if you're new to cutters...engage the PTO at a low RPM. When you are finished mowing, reduce the engine RPM to idle before disengaging the PTO...that's easier on the equipment.

$100 is an awfully good price for a decent mower. I'd be suspicious and give it a thorough going over.

Definitely a good price!

 

[gwdixon]

How many of these folks do you know?

Two....me and now you since you think it is a good idea. :laughing:

 

[RickB]

Two....me and now you since you think it is a good idea. :laughing:

I'm thinking we are back to one :anyone:

 

[Ductape]

Two Bud Light's before getting on tractor. Two more 1 hr later.

OK, I try not to preach too much on this forum. This time I simply cannot hold back. This is some of the worst advice I've ever seen on here. Who would do this????? Bush hogging is a tough task, where you need to pay attention. You could hit wire fencing, rocks, old fence posts...... etc. You could damage your bush hog, damage your tractor...... who knows what else ??? I mean, what kind of TBNer would go and recommend another TBNer ......... to drink LIGHT beer ?????

 

[deezler]

^^ bwaaaa hahaha. My thoughts exactly.

 

[deezler]

To add something a little more productive to the thread, I am going through this exact process right now myself.

I am a little embarrassed about what I paid for my old beat up king-kutter vs your $100 scoop, but! That's ok.

I did not really do my due dilligence upon picking mine up and took the craigslist ad for it's word (barely ever used, great shape, etc). It should have been pretty obvious that the PTO shaft wouldn't telescope, and that the shear pin was clearly busted and spun, causing all sorts of headaches... but my truck was already stuck in the mud in their yard before I even saw it, and I got flustered.

So after getting the cutter home, I was a little sad when I did my secondary (primary) inspection of it. I had to end up cutting the PTO shaft coupler off the rotary cutter's gearbox input shaft due to the smeared out shear pin. I guess that was the only real blemish on it though.

So after getting the shaft off, I decided to clean it up a bit today (sorry for the old phone pics)

I don't have an impact wrench right now, so I decided to just grind up the blade edges a little bit without taking them off. Nothing dramatic, just taking out the rock strikes and putting a little edge back on there. Next winter I may try to remove the blades and grind them cleaner... should it prove necessary.

Before:

After:

Then I changed the gear box oil (extracted it with a pella vacuum pump) and filled the gearbox ~75% with new 75w90 gear oil.

Lubed the rear wheel assembly and a few pivots, and she's ready for the new PTO shaft (arriving tomorrow).

 

[plaindave]

Thanks for the input. Weather turned cold so I haven't done anything but it's supposed to be back in the 60's tomorrow so I will be outside.

The PTO shaft is stiff and doesn't slide much - I was concerned that it may be a problem. I'll hit it with the PB Blaster and see if it improves.

The price was a great deal. It was from a horse farm going out of business. I bought it on the last day before they moved, gave them a lowball offer and they accepted. Apparently nobody buys brush cutters between Christmas and New Years.

 

[djradz]

I'm thinking we are back to one :anyone:

Since you asked. I think we're at least closer to 2. I basically agree with the following statement.

"... the one that is being discussed is to get it as tight as you can with an impact wrench so you'll be able to remove the nut(s) with the same impact wrench (hopefully)."

This is the philosopy I use for many applications, and have done enough checking with a torque wrench to confirm I'm in the balpark. Often, the case is one where I just cannot position anything well enough to block the blade, or whatever it is I'm trying to tighten, well enough so I can tighten the nut or bolt at the same time. I've successfully used this on both my Woods RFM and a KK (blue just like the pics) deck for over 20 years.

 

[deezler]

Yeah.. not happening. King Kutter manual says to tighten the blade bolts to 310 lbf-ft !!!

I am pleased to report that my KK brush hog kicks *****. It can easily chop down a wall of 2" saplings. Has me wanting more seat time!