Bottom seal replacement on a Woods BB720X rotary cutter

[MinnesotaEric]

The bottom seal on my rotary cutter is so bad that even grease leaks out, and both the nut and stump jumper on the bottom of rotary cutters are notoriously hard to remove. As such, I anticipate needing enough room to use an acetylene torch, 1” impact tools, and anger under this thing while keeping it steady enough to not get squished like a bug.

Any tips from anybody with a been there, done that t-shirt? Like, is the nut left-hand or right-hand thread? (I haven't looked.)

I just put this thing up on the wire spool and cribbing this evening as an experiment. The loader would be used only as a safety, but after centering the pull, I'm thinking I will bridle either one longer strap or bridle two separate straps to my loader. I do have a loader lock in, but I should make another loader lock so I can lock BOTH sides. The rotary cutter weighs just over 1200 pounds.

 

[flyerdan]

Is there any reason that you can't flip it over and set it on sawhorses so you can get to everything easily? I would do that, and tack weld a long bar on the stump jumper and put a cheater on the breaker bar, pull the two toward each other. If you have help, maybe an air hammer with a dull chisel on the edge of the socket to help it along.

 

[MinnesotaEric]

Is there any reason that you can't flip it over and set it on sawhorses so you can get to everything easily? I would do that, and tack weld a long bar on the stump jumper and put a cheater on the breaker bar, pull the two toward each other. If you have help, maybe an air hammer with a dull chisel on the edge of the socket to help it along.

I need to remove the gearbox so I can replace whatever is needed inside. That said, I'll find out how I need to hold the cutter from spinning when I look at it.

 

[Sawyer Rob]

Nothing is needed inside, the seal goes in from the outside.

Just make sure the replacement seal is the newly designed "triple lip" seal.

SR

 

[RayIN]

The nuts are RH, and screw onto a keyed shoulder bolt; so no concern about the bolt spinning in the stump-jumper. I enlarged the hole in the deck so a 3/4 socket fits nicely.
The first time removing the nuts I had to use heat. When I reassembled the bolt N nut I used ThreadEzze. i've never had to repeat that process, the nut unscrews easily every time after the lock washer tension is removed.
I have sharpening the blades down, I block up the bush hog with 2, 6" pole cutoffs. Loosen the nuts, and the tilt of the blades holds the bolt in the hole.
Crawl under, raise the blade tip a bit, the bolt falls out.
I use a 6" grinder to sharpen the blades, then reassemble. That used to take about 1 hr, but age has slowed me, now it's 2 hrs.

 

[Sawyer Rob]

The nuts are RH, and screw onto a keyed shoulder bolt; so no concern about the bolt spinning in the stump-jumper. I enlarged the hole in the deck so a 3/4 socket fits nicely.
The first time removing the nuts I had to use heat. When I reassembled the bolt N nut I used ThreadEzze. i've never had to repeat that process, the nut unscrews easily every time after the lock washer tension is removed.
I have sharpening the blades down, I block up the bush hog with 2, 6" pole cutoffs. Loosen the nuts, and the tilt of the blades holds the bolt in the hole.
Crawl under, raise the blade tip a bit, the bolt falls out.
I use a 6" grinder to sharpen the blades, then reassemble. That used to take about 1 hr, but age has slowed me, now it's 2 hrs.

First of all, he's not asking about taking the blades off!

Secondly, IF he was, it's obvious you have never taken the blades off a Woods bb720!!

SR

 

[RayIN]

First of all, he's not asking about taking the blades off!

Secondly, IF he was, it's obvious you have never taken the blades off a Woods bb720!!

SR

you are certainly entitled to your opinion.

 

[Sawyer Rob]

you are certainly entitled to your opinion.

Why thankyou for your permission...

At least I've done the exact job the OP is trying to do!

SR

 

[4570Man]

I’m not sure why you would attempt to work on it that way. Flip it all the way over.

 

[ruffdog]

I’m not sure why you would attempt to work on it that way. Flip it all the way over.

Yes^^^at least stand it up on the front end with the wheel in the air. With one rotary cutter, I drilled and tapped a 1/2-13 hole on each side of the nut that holds the SJ on. That way I could use my puller to pull it off. Then, just grease up a bolt and plug the hole for next time.