Woods MD-160 gearbox destruction

[DeudeMann]

So I have a small (big) problem with my Woods MD-160 shredder. I am 99% sure the gearbox assembly is broken. Or put another way, the bottom half of the housing has cracked off, leaving the output shaft to wobble freely. This means that all of the gear oil drained out of the bottom while it was spinning and therefore the innards of the gearbox are probably damaged as well.

Here is a vid of the condition of the output shaft looking from underneath the cutter deck. You can see that half of the cylindrical structure on the gearbox housing is gone and the shaft is, well, wobbling like a drunken sailor.
[video]https://photos.app.goo.gl/KivKAKYB685fegKf9[/video]

I have not taken it apart yet but I am guessing most of it is toast, and it might be time for a replacement gearbox. I am looking around for pricing. Are there any suggestions out there for good sources for new or remanufactured gearboxes?

I am thinking I want to stay away from used; I bought this as a used shredder and I have no idea how the previous owner treated it. I also do not want gearbox replacement to turn into a new hobby.

Thanks in advance

 

[DeudeMann]

Here is what the gearbox looks like. It is a brute, although apparently not indestructible.

 

[DeudeMann]

So an initial search is showing the stock Woods gearbox is an $1100+ item. OUCH. I am thinking it might be worth considering retrofit of another gearbox, maybe even an oversized one. For example Grizzly has a 100 HP unit for less than $300, with a side mount configuration like the Woods gearbox. However I have not checked the exact fitment.

Thoughts on the retrofit approach?

 

[dusty3030]

Well, if the OE is worth more than the whole cutter is worth - do you really have a choice but to try something else?

Problem is though, will the existing stump jumper / blade holder fit a different box.

 

[DeudeMann]

Yes on the stump jumper... From what I have measured the shaft mate on the stump jumper is a 1.5" diameter shaft with a keyway cut. Perusing around at universal gearboxes I have not seen that yet.

I am hoping there is an option I have not considered other than calling this shredder trash and buying another one. It is a beefy unit.

 

[radios1]

it could be just a toast lower bearing and seal. is there resistance to turning the shaft?. the gears may still be good.. here's another guy with the same problem. https://www.tractorbynet.com/forums/attachments/24965-woods-gearbox-gives-out-again.html a better brand uses 000 grease in their gearboxes, it can't leak out..

 

[DeudeMann]

Thanks for the link.

Yes I need to pull the gearbox out and take a look at the internals. I'll be doing that soon.

 

[dusty3030]

Thanks for the link.

Yes I need to pull the gearbox out and take a look at the internals. I'll be doing that soon.

If I saw your video correctly there is a chunk of the lower gearbox missing? If not, then by all means I'd try and replace the bearings / seals and rock on with the box you have.

 

[DeudeMann]

YEs there is definitely a chunk of the lower gearbox missing. From what I can tell from the Woods parts diagrams it is part of the main casting, and not a separate piece like the one for the horizontal (input) shaft.

So I just got off of the phone with Woods. That piece that is broken is part of the main gearbox casting, so at the very least I would be looking at purchasing a new case. The case alone is $325, and that assumes I would not need to replace any of the other components. Since it ran dry for at least the few seconds it took for me to shut it down, I am concerned there may be more damage internally. I can pull off the top plate and have a look without pulling the gear box from the deck so I'll do that next.

 

[def38]

Bearings and seal are likely low cost items that are standard, off-the-shelf items. You can likely rebuild the whole thing for less than $50.00 in parts as long as the gears and shafts are not damaged. Be sure to purchase non-Chicomm bearings. I prefer FAG bearings (German manufacturer with unquestioned quality) and double lip seal with garter spring tensioner.

As for lubricant, use what is specified in the gearcase. GL-5 gear oil is likely the recommended lubricant. I usually buy a brand name synthetic GL-5 at Wal-mart, even Supertech (Wal-mart brand lubricants). I ad a bit of moly (molybdenum disulphide, a friction modifier) to my gearcases. I have never had one fail.

You were posting as I was composing so I did not see your damaged case casting text.