Ancient Mott flail mower gearbox dissasembly

Captain Ledd · Jul 18, 2013

Most of my resources for rebuilding this thing have come from this website. I'm really hoping someone can help me out.

2nd post here, and I've run into a bit of a head scratcher.

I have an old Mott Flail mower (60's?) that I'm rebuilding/restoring for me and my neighbor to use. Mostly it's just required bearings and a bit (a LOT) of welding back together. But while painting the gearbox and sitting it on it's side it became MOST apparent that the seals were no good... Measured shafts and openings, ordered nice double lip neoprene seals, went to pry the old seals out and I swear the front (input) seal case was made out of spring steel or something (turned out it was just a FELT seal too!), the side seal (output) was a normal seal, and wasn't an issue.

But this front seal I just could not remove, the only direction it went was farther into the gearbox. So I figured I'd just pop the front cover off (which I was kinda trying to avoid seeing as it was already painted) and replace the seal that way.

Well, there's my problem, the cover is STUCK about 1/8" up from the face of the housing, I'm bending screwdrivers prying on it and I don't want to break or bend anything, especially the cover. But I can't even get a good look in there to see what it's caught on. Any help or diagrams on how this thing comes apart would be great. It's got a different style housing than basically every other Mott I've seen, I have searched.

(hopefully my attachment works)

leonz · Jul 18, 2013

About your gearbox,

it should not be caught on anything,
Its just difficult to remove as there is a bearing set behind
the shaft collar.

what you need are proper curved edge pry bars,
preferrably 3 of them to gradually push the end
cover out and away as you are pushing up against
the shaft collar and there is most likely a lot of rust
and dirt there.

YOU have to pry the cover off evenly one bite at time
to get it to free itself and by that I mean 1/8 of an inch
at a time.

OH and by the way if the seals are leaking the shafts and bearings
need to be replaced as they are worn enough that the seals leak.
I realise thats something you do not want to hear but.....................

Plase send your e-mail to lzaharis@lightlink.com so I may forward
a Mott mower manual to you as the mail box on the forum will not
allow me to upload it as it is too big.

I believe parts for this gearbox are still readily available and the flailmaster folks can help with parts for it.

Captain Ledd · Jul 18, 2013

The shafts look to be decent at the moment. Bearings felt tight and at least seemed smooth enough, but there's no telling what they would sound like once under power. I'll double check them.

The side (output) I have off and the seal surface is good and smooth. I didn't realize before I tried to remove it that the front seal was actually just felt. It really wasn't covered in that much grease when I got it, only when I tipped it over did it start oozing.

Thanks a ton, I'll be sending you an E-mail in just a few minutes.

Captain Ledd · Jul 21, 2013

Enlisted the help of my brother while he was over. Wasn't enough space for crowbars initially, but I wedged in 3 old railroad spikes evenly spaced, and the finished it off with the crowbars.

Thanks again for the help.

The bearings are actually in great shape, very, very little wiggle, didn't appear to have any flat spots or damage. Nice and smooth.

The shafts however were another story, those felt seals are junk and pitted this poor thing to no end. Some more cleaning revealed the damage to the side shaft. So I'll be ordering some Speedi-Sleeve's Monday morning, and hopefully those will do the trick.

I give you these pictures for your viewing (dis)pleasure.

LEFT: The felt seal once I finally got it out.
MIDDLE: The side output shaft
RIGHT: The main input shaft

leonz · Jul 21, 2013

Re: Ancient Mott flail mower gearbox dissassembly

Captain Ledd said:
Enlisted the help of my brother while he was over. Wasn't enough space for crowbars initially, but I wedged in 3 old railroad spikes evenly spaced, and the finished it off with the crowbars.

Thanks again for the help.

The bearings are actually in great shape, very, very little wiggle, didn't appear to have any flat spots or damage. Nice and smooth.

The shafts however were another story, those felt seals are junk and pitted this poor thing to no end. Some more cleaning revealed the damage to the side shaft. So I'll be ordering some Speedi-Sleeve's Monday morning, and hopefully those will do the trick.

I give you these pictures for your viewing (dis)pleasure.

LEFT: The felt seal once I finally got it out.
MIDDLE: The side output shaft
RIGHT: The main input shaft

__________________________________________________________________________________________________

UMMM,

The rust on your bearings is a really really bad sign,
there should be zero wiggle period

The shafts are also in really really bad shape.

Sadly no speedy sleeve will cure this for you as the sleeve will not stay in place.
AND the old shafts will destroy the new seals.
I would check with the folks at flail master about buying a new gearbox if I were you.