Flail Mower New to Me- Seppi SMO 200 Flail Mower

[leonz]

Good morning Doug,

It is heavier than molasses, apparently Tractor Supply has it in squeeze bottles.
I would buy at least 3 bottles which should cover the bearings in the cross shaft
tube as well.


Happy mowing

 

[arto98607]

It looks like a spoke too soon concerning the gearbox input shaft seal. It is leaking. Not terribly bad, but it is leaking. This is a pic of the front of the gearbox right after I bought the machine:
View attachment 1443807

Has anyone here ever changed a seal on a gearbox such as this?

View attachment 1443809
It looks like once the front cover is removed, parts 5-29 will come out of the housing. Then slide the seal (part #5) off the shaft and then slide the new seal back on. Am I seeing this right?

Thanks for your time,
Doug

Hello Doug,
I replaced the input shaft seal on my old Ford 917L flail mower about four years ago when I bought it.

I have used 80W-90 gear oil since and it has not leaked at all - the shaft surface was in pretty good shape.






Not opposed to 00-grease, but the gearbox was probably not designed for it as far as I know and would consider it as the last resort.

I have used it in a junky old rototiller chain drive and best I can say is it stopped the leak...

 

[Doug Vee]

I think I will hold off on buying anything until I get the gearbox apart. I will measure the shaft and decide from there how I will address the leak. Thank you all for the input,

Doug

 

[Doug Vee]

Gearbox is open. I measured the shaft with calipers. It is 72 mm on the nose. I ordered a new seal which should be here mid next week. If I have time during our bathroom remodel project, I will get it installed next week.

Doug

 

[Doug Vee]

The seal replacement went well. A couple days later I took the mower out and mulched some garden materials. I ran it for 10 or 15 minutes. The next day I checked the input shaft seal and it is nice and dry. Unfortunately, the output shaft seal is wet, where it was dry after my initial 4 hour mow...I should have known that would be the case.

The horizontal output shaft housing design is dry- there is a seal on the gearbox end of the output shaft housing to keep oil in the gearbox. The other end, the sheave end, has a zerk fitting, with a seal on the sheave end of the output shaft housing. I bought both of those seals.

Now I can get more practice removing and reinstalling the gearbox. It's not all bad, dumping the gearbox oil will be good to flush out remaining contaminates.

Doug

 

[blitzen]

Nice, thanks for the update.

 

[Doug Vee]

I removed the gearbox and separated the output shaft housing from the gearbox housing. The output housing sleeves into the gearbox housing with a slight taped fit, and has an O-ring groove machined in it. The O-ring is shown in the parts diagram. There is also what the parts breakdown describes as a "gasket" between the mating surface flanges of each housing. When I opened up the joint, the O-ring was non-existent and the "gasket" was only half there.

I bought seals for each end of the output housing so I would have them when I had a chance to tear into this. As I was observing how the pinion gear and the bearing are located all on the gearbox side of the output shaft seal, I came to the realization that the output shaft seal would not seal the mating joint from leakage, it would prevent gear oil from migrating into the output shaft housing tube. The bearing on the sheave end of the output shaft is lubricated by a zerk fitting and has it's own seal, so the output shaft housing tube is to be dry inside, which is how I understood it to be. I do not think there is any reason to further disassemble the output shaft assembly, as there is no evidence that they are leaking. It appears that the O-ring is the seal between the gearbox housing and the output shaft housing joint where the current leak is evident.

I took the gasket to one of the local heavy truck repair shops to see if I could procure some gasket material to make a new gasket. The shop foreman looked at the piece that I had to match up and he told me that it is not an oil seal gasket. Due to the mating of the ring and pinion gears within the gearbox, he said that it is a shim. He measured it with a precision caliper and it measured .011".

The "gasket" appears to be metallic, but it was non-magnetic, so I was thinking that it might be aluminum or brass or...? I have done some searching on McMaster-Carr and have not found anything that measures .011". The closest I can get is .010, with the option of stacking a .001" layer with it. The truck shop foreman told me that he has used paper in a pinch.

I guess I will check with the machine shop that has helped me on the mower and see if they have any material or ideas for me. And if anyone has any bright ideas to share, I'm open to hearing them.

Thank you,
Doug

 

[leonz]

Buy the sheet gaskets from Mcmaster-Carr.

 

[Doug Vee]

Just to follow up. Made the shim/gaskets (from McMaster-Carr) and reassembled the gearbox/output shaft. I filled the gearbox on the bench and let it sit there a couple of days before I remounted the assembly on the mower. So far the o-ring seal is working...though not under much stress, just sitting there with cold 80/90 weight in it. We'll see how it does this spring.

Doug

 

[Doug Vee]

Just to follow up. Made the shim/gaskets (from McMaster-Carr) and reassembled the gearbox/output shaft. I filled the gearbox on the bench and let it sit there a couple of days before I remounted the assembly on the mower. So far the o-ring seal is working...though not under much stress, just sitting there with cold 80/90 weight in it. We'll see how it does this spring.

Doug

I did not get to mow any this spring, but did get some mowing done this week. Everything seems to be working fine.

I added two rear remote circuits to my L48. A swing cylinder was included in the old flail mower, so I reinstalled it and was able to use it while mowing. I am using the backhoe swing cylinder pressure line to provide power and the backhoe return line back to tank.

A view of the mower fully retracted, with the rear remote valves and connections:
View attachment IMG_1760.jpeg

Having the ability to offset more or less is way cool. It is really nice for mowing the fence line. And for mowing near obstacles like trees.

So far the new seals seem to be holding up also. A big plus, needless to say.

Next addition will be hydraulic top and side links. I think the side link will help me get further into the ditch line. Though it won't be a ditch bank machine, I think it will be good enough for what I want to accomplish.

Doug