Bottom seal replacement on a Woods BB720X rotary cutter

[MinnesotaEric]

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

According to Woods, you are right, there is a new triple-lip seal that fits in place of the old seal (p/n 39289), and the part number for the new triple-lip seal is 1045872. I was informed that I will also need a protective seal (p/n 57338). Anyway, I'm going to order those parts in before getting into it.

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.

So you used the two 1/2-13 holes you made as jack bolts to pop the stump jumper off? I will keep that idea in mind when I get the seals ordered in.

 

[ruffdog]

So you used the two 1/2-13 holes you made as jack bolts to pop the stump jumper off? I will keep that idea in mind when I get the seals ordered in.

The two bolts were used to fasten my puller to the stump jumper. Then my puller pushed against the center of the gearbox shaft.

 

[MinnesotaEric]

I ordered the seals and on Ruffdog's suggestion, tonight I leaned it up against a tree.

 

[ruffdog]

I ordered the seals and on Ruffdog's suggestion, tonight I leaned it up against a tree.

View attachment 3869811

View attachment 3869812

Yep Trees work good. Your stump jumper looks different than my solid one. Can you get the fingers of a regular gear puller through the openings to pull it?

 

[gengine]

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

Why don't you provide something useful and helpful to this? I had to take the stump jumper and blades off of mine to remove the gearbox, they wouldn't fit through the tiny hole in the top of the mower deck.

 

[Sawyer Rob]

Why don't you provide something useful and helpful to this?

Did you read my first answer? I did provide the most valuable info in the whole thread, that is IF he doesn't want to have to do it again soon. AND what "useful" info did your post provide??

SR

 

[RayIN]

Why don't you provide something useful and helpful to this? I had to take the stump jumper and blades off of mine to remove the gearbox, they wouldn't fit through the tiny hole in the top of the mower deck.

On sawyer Bobs behalf; he obviously knows how to replace the seal without removing the blades. He rebuked me for writing how I removed my blades.

 

[MinnesotaEric]

So, popping everything apart is child's play. I first foam-cannoned the underside to get rid of any poison ivy oil.

I then pulled the cutterpin, which was the hardest thing to do, put a 1-13/16" socket on a 3/4" drive impact and winged the nut off.

I then threaded the nut most of the way back on but did not bottom it out. I then took a 3' pry bar behind the stump jumper, applied a bunch of pressure (being heavy has advantages, heh!) and whacked the nut with a three-pound hammer, and the stump jumper popped loose with no fear of it falling off since it was still retained by the loose nut (no photos because I was using both hands).

Super easy, no pullers are needed.

Basically, my technique was exactly like removing front-end parts and stuck clutches on power equipment.

The good news is that I had thought that at the very least, the bottom bearing had shelled to mess up the lower shaft seal. Maybe, but the play isn't that bad, so despite the new triple seal costing $80 (without dinner and a movie first), I'm going to punt on removing the gearbox to pull the bearings out and clean up the output shaft with 600, 1000, 1500 grit sand paper if a can catch a fingernail* and then fill the gearbox back up with cornhead grease when I replace the seal and seal protector.

In the meantime, tomorrow morning I'm going in for a knee operation, so if there is a gap in my reassembly photos, knee operation, see. The seals are expected to arrive next week.

* Believe it or not, a fingernail run across a smooth surface can catch down to about a 5 ten-thousandth deviation.

 

[4570Man]

On sawyer Bobs behalf; he obviously knows how to replace the seal without removing the blades. He rebuked me for writing how I removed my blades.

You don’t have to remove the blades. You do have to remove the stump jumper.

 

[MinnesotaEric]

While my bum knee is on the mend, I did replace the seal today. I couldn't get a seal pick or something like it to pop the seal out, so I drilled a hole and used a cotter pin puller to pop the old seal out. If that had not worked, I would have used a slide hammer with a screw threaded into the hole to pull the old seal out.

Comparing the old protective seal with the new one, either there has been a design change, or the protective seal functions a bit as a crush washer when the stump jumper is tightened down. I haven't flipped my stump jumper to look at it, because old age and treachery makes me think it doing so is a two-man job.